Anal Chem, 2002 Mar 15, 74(6), 1458 - 61 UV resonance raman spectroscopic detection of nitrate and nitrite in wastewater treatment processes; Lanoul A et al.; The 204- and 229-nm excited UV resonance Raman spectra of wastewater solutions containing sodium nitrite and nitrate were measured in the concentration range 7 microM to 3.5 mM (0.1-50 ppm nitrogen) . The other chemical species present in wastewater do not interfere with Raman measurements of NO2-/NO3- bands . We observe detection limits of < 14 microM (< 200 ppb) for both NO2- and NO3- . UV resonance Raman spectroscopy appears to be an excellent tool for on-line monitoring of NO2-/NO3- in wastewater for the real-time control of water treatment plants. Appl Environ Microbiol, 2002 Apr, 68(4), 1947 - 54 Shedding of Escherichia coli O157:H7 in dairy cattle housed in a confined environment following waterborne inoculation; Shere JA et al.; A study of Escherichia coli O157:H7 transmission and shedding was conducted with bull calves housed in individual pens within a confined environment . For comparative purposes, the numbers and duration of E . coli O157:H7 shedding in naturally infected calves were monitored after a single purchased calf (calf 156) tested positive prior to inoculation . During the next 8 days, the calves in adjacent pens and a pen directly across a walkway from calf 156 began to shed this serotype O157:H7 strain . Five of the eight calves in this room shed this O157:H7 strain at some time during the following 8 weeks . The numbers of E . coli O157:H7 isolates shed in these calves varied from 60 to 10(5) CFU/g of feces, and the duration of shedding ranged from 17 to >31 days . The genomic DNAs from isolates recovered from these calves were indistinguishable when compared by using XbaI digestion and pulsed-field gel electrophoresis . Inoculation of calves with 1 liter of water containing ca . 10(3) to 10(4) CFU of E . coli O157:H7/ml resulted in shedding in 10 of 12 calves (trial 1, 4 of 4 calves; trial 2, 6 of 8 calves) . The inoculated calves shed the inoculation strain (FRIK 1275) as early as 24 h after administration . The duration of shedding varied from 18 to >43 days at levels from 10(2) to 10(6) CFU/g of feces . The numbers of doses necessary to initiate shedding varied among calves, and two calves in trial 2 never shed FRIK 1275 after four doses (ca . 10(6) CFU per dose) . Results from this study confirm previous reports of animal-to-animal and waterborne dissemination of E . coli O157:H7 and highlight the need for an effective water treatment to reduce the spread of this pathogen in cattle. Water Res, 2002 Mar, 36(5), 1379 - 84 Removal of THM precursors by GAC: Ankara case study; Capar G et al.; The effectiveness of granular activated carbon (GAC) adsorption for the removal of natural organic matter and trihalomethanes from Ivedik Water Treatment Plant of Ankara City is investigated . Freundlich Isotherm constants K and n were determined as 17.61 and 1.66, respectively . Bench-scale GAC columns were run with empty bed contact times (EBCT) varying from 0.40 to 2.67 min to evaluate adsorption performance . 50% exhaustion values were used for comparison . The treated volumes of water increased with EBCT, showing a linear increase in GAC service life . Correspondingly, the carbon usage rate decreased . The capacities calculated by the isotherm equation and achieved by columns were also compared . The column capacities were within 43-65% of the isotherm capacities at complete breakthrough . However, they were only within 8-17% of the isotherm capacities at 50% breakthrough. Water Sci Technol, 2002, 45(3), 61 - 9 Erosion mechanisms in combined sewers and the potential for pollutant release to receiving waters and water treatment plants; McIlhatton TD et al.; The problems associated with solids in sewerage systems result in common difficulties such as blockages and flooding and the subsequent maintenance requirements have been well documented . Concerns regarding pollutant release have also been demonstrated, with the contribution from in-sewer solids to the quality of the flow during a storm event being especially significant . These events known as "foul flushes" in combined sewers typically occur in the initial period of storm flows, when the concentration of suspended sediments and other pollutants are significantly higher than at other times . Traditionally impacts from these events have been related to the suspended solids phase of the flow passing through a CSO structure . It is now apparent that much of the suspended load originates from solids eroded from the bed . The "near bed solids" which are re-entrained into the flow, together with solids eroded from the bulk bed, account for large changes in the suspended sediment concentration under time varying flow conditions . The influence of these eroded solids and their potential impact on receiving waters and treatment plants will be reviewed using data obtained from field studies carried out in the main Dundee interceptor sewer in Scotland . This paper describes some of the methods employed to investigate the characteristics of the pollutants associated with solids erosion in combined sewers. Epidemiol Infect, 2002 Feb, 128(1), 73 - 81 Risk factors in HIV-associated diarrhoeal disease: the role of drinking water, medication and immune status; Eisenberg JN et al.; In a cross-sectional survey of 226 HIV-infected men, we examined the occurrence of diarrhoea and its relationship to drinking water consumption patterns, risk behaviours, immune status and medication use . Diarrhoea was reported by 47% of the respondents . Neither drinking boiled nor filtered water was significantly associated with diarrhoea (OR = 0.5 {0.2, 1.6}, 1.2 {0.6, 2.5} respectively), whereas those that drank bottled water were at risk for diarrhoea (OR = 3.0 {1.1, 7.8}) . Overall, 47% always or often used at least one water treatment . Of the 37% who were very concerned about drinking water, 62% had diarrhoea, 70% always or often used at least one water treatment . An increase in CD4 count was protective only for those with a low risk of diarrhoea associated with medication (OR = 0.6 {0.5, 0.9}) . A 30% attributable risk to diarrhoea was estimated for those with high medication risk compared to those with low medication risk . The significant association between concern with drinking water and diarrhoea as well as between concern with drinking water and water treatment suggests awareness that drinking water is a potential transmission pathway for diarrhoeal disease . At the same time we found that a significant portion of diarrhoea was associated with other sources not related to drinking water such as medication usage. J Environ Sci (China), 2002 Jan, 14(1), 49 - 53 Double catholyte electrochemical approach for preparing ferrate-aluminum: a compound oxidant-coagulant for water purification; Qu JH et al.; Ferrate is an excellent water treatment agent for its multi-functions in oxidation, disinfection, coagulation and adsorption, but its coagulation ability depends on its dosage and is after its oxidation . This paper focuses on preparing a new kind of ferrate combined with alum to enhance its coagulation function for water purification . An effective electrolysis reactor was designed and employed in the test . Some key parameters in the process of electrolysis concerning the preparation efficiency, such as the current density, temperature and alkalinity were also investigated . The proper conditions for ferrate-alum preparation were determined . Under the condition of 5 V given voltage, 6 h electrolyzing interval, below 2% alum concentration (in weight), a combined liquid ferrate-alum products was successfully prepared, which contained 0.0294 mol/L FeO4(2-) and 0.0302 mol/L total soluble ferron with 2% Al2O3 . There was no insoluble ferron produced by controlling an optimum electrochemical condition. Environ Monit Assess, 2002 Feb, 73(3), 253 - 62 Trihalomethane formation potential and concentration changes during water treatment at Mumbai (India); Thacker NP et al.; The treated water at the outlet of treatment plants and representative service reservoirs of Mumbai city have been evaluated for trihalomethane formation potential in 1995-1996 . Chloroform, dichlorobromomethane, chlorodibromomethane and bromoform have been monitored during monsoon, winter and summer . The levels of chloroform are found above the regulated WHO guideline value of 200 microg L(-1) in final water during postmonsoon at Ghatkopar (226 microg L(-1)), Malbar (210.3 microg L(-1)) and Tulsi (231.26 microg L(-1)). Environ Sci Technol, 2002 Feb 15, 36(4), 662 - 8 Modeling the kinetics of ferrous iron oxidation by monochloramine; Vikesland PJ et al.; The maintenance of disinfectants in distribution systems is necessary to ensure drinking water safety . Reactions with oxidizable species can however lead to undesirable disinfectant losses . Previous work has shown that the presence of Fe(II) can cause monochloramine loss in distribution system waters . This paper further examines these reactions and presents a reaction mechanism and kinetic model . The mechanism includes both aqueous-phase reactions and surface-catalyzed reactions involving the iron oxide product . In addition, it considers competitive reactions involving the amidogen radical that lead to a nonelementary stoichiometry . Using the method of initial rates, the aqueous-phase reactions were found to have first-order dependencies on Fe(II), NH2Cl, and OH- and a rate coefficient (kNH2Cl,soln) of 3.10 (+/-0.560) x 10(9) M(-2) min(-1) . The surface-mediated reactions were modeled by assuming the formation of two surface species: >FeOFe+ and >FeOFeOH . Using numerical techniques, combined rate coefficients for the surface-mediated processes were determined to be 0.56 M(-3) min(-1) and 3.5 x 10(-18) M(-4) min(-1), respectively . The model was then used to examine monochloramine and Fe(II) stability under conditions similar to those observed in distribution systems . Our findings suggest the potential utility of monochloramine as an oxidant for Fe(III) removal in drinking water treatment. Semin Dial, 2002 Jan-Feb, 15(1), 50 - 2 Water treatment for hemodialysis: ensuring patient safety; Ouseph R et al.; Patient safety has become an important focus of the Institute of Medicine and the medical community . Although hemodialysis is a routine therapy, it is nonetheless a complex procedure where errors can occur . In particular, errors related to water quality can lead to patient injury and to increased medical costs . Using the Institute of Medicine report on errors in medicine as a basis, this article discusses previously published incidents of patient injury related to water quality in terms of the types of errors that occurred . Epidemiologic techniques provide a framework to identify, correct, and possibly avert these types of errors in the future . While the ultimate responsibility for ensuring water quality rests with the medical director of the hemodialysis unit, patient safety should be a concern of all members of the nephrology community. Appl Environ Microbiol, 2002 Mar, 68(3), 1025 - 32 Chlorine disinfection of atypical mycobacteria isolated from a water distribution system; Le Dantec C et al.; We studied the resistance of various mycobacteria isolated from a water distribution system to chlorine . Chlorine disinfection efficiency is expressed as the coefficient of lethality (liters per minute per milligram) as follows: Mycobacterium fortuitum (0.02) > M . chelonae (0.03) > M . gordonae (0.09) > M . aurum (0.19) . For a C.t value (product of the disinfectant concentration and contact time) of 60 mg.min.liter(-1), frequently used in water treatment lines, chlorine disinfection inactivates over 4 log units of M . gordonae and 1.5 log units of M . fortuitum or M . chelonae . C.t values determined under similar conditions show that even the most susceptible species, M . aurum and M . gordonae, are 100 and 330 times more resistant to chlorine than Escherichia coli . We also investigated the effects of different parameters (medium, pH, and temperature) on chlorine disinfection in a chlorine-resistant M . gordonae model . Our experimental results follow the Arrhenius equation, allowing the inactivation rate to be predicted at different temperatures . Our results show that M . gordonae is more resistant to chlorine in low-nutrient media, such as those encountered in water, and that an increase in temperature (from 4 degrees C to 25 degrees C) and a decrease in pH result in better inactivation. J Appl Microbiol, 2002, 92(3), 566 - 73 Mechanisms contributing to hypochlorous acid resistance of a Salmonella isolate from a poultry-processing plant; Mokgatla RM et al.; AIMS: We have recently reported the isolation of Salmonella that have acquired tolerance to hypochlorous acid (HOCl) (Mokgatla et al . 1998) . The aim of this work was to investigate possible protective mechanisms involved in the increased tolerance to HOCl of a selected resistant strain . METHODS AND RESULTS: One resistant (Salmonella 104) and one sensitive (Salmonella 81) isolate in exponential phase were exposed to HOCl at a final active concentration of 28 mg l(-1) . Cultures were assayed for superoxide dismutase and catalase activity, as well as for four membrane-bound dehydrogenases (malate, lactate, glutamate and glucose-6-phosphate dehydrogenase) . The degree of single-strand breaks in genomic DNA was analysed and lipopolysaccharide profiles determined . The resistant Salmonella isolate differed from the sensitive isolate in a number of ways . It responded within 10 min of exposure by producing catalase and decreasing the activity levels of four membrane-bound dehydrogenases . This combination would lead to lower levels of hydroxyl radicals and singlet oxygen, moieties thought to be integrally involved in the antibacterial action of HOCl . Furthermore, the resistant strain did not display the same degree of DNA damage as did the sensitive strain . CONCLUSIONS: Strain 104 is believed to grow in the presence of 28 mg l(-1) HOCl by protecting itself against HOCl by decreasing the levels of species that could react with HOCl to generate toxic reactive oxygen radicals and by improved DNA damage repair mechanisms . SIGNIFICANCE AND IMPACT OF THE STUDY: The occurrence of Salmonella able to grow in the presence of 28 mg l(-1) HOCl is of relevance to the food-processing and drinking water treatment industries as these strains would survive sanitation regimes. J Environ Monit, 2002 Feb, 4(1), 43 - 7 Monitoring dissolved organic carbon in surface and drinking waters; Volk C et al.; The presence of natural organic matter (NOM) strongly impacts drinking water treatment, water quality, and water behavior during distribution . Dissolved organic carbon (DOC) concentrations were determined daily over a 22 month period in river water before and after conventional drinking water treatment using an on-line total organic carbon (TOC) analyzer . Quantitative and qualitative variations in organic matter were related to precipitation and runoff, seasons and operating conditions . Following a rainfall event, DOC levels could increase by 3.5 fold over baseflow concentrations, while color, UV absorbance values and turbidity increased by a factor of 8, 12 and 300, respectively . Treated water DOC levels were closely related to the source water quality, with an average organic matter removal of 42% after treatment. J Environ Monit, 2002 Feb, 4(1), 16 - 9 The role of size exclusion chromatography-flame atomic absorption spectrometry in the treatment chemistry of potable water; Koether MC; The percentage composition of Al13, {AlO4Al12(OH)24(H2O)12}7+, in water treatment coagulants is an important criterion in the development and use of polymeric coagulants . Polymeric coagulants are generally used in cold climates or with highly turbid waters . Size exclusion chromatography flame atomic absorption spectrometry (SEC-FAAS) can separate Al13 and monomeric Al within 6 min . The percentage composition of Al13 and monomeric Al is determined by solving two simultaneous equations . Due to overlapping peaks, a 10% error is associated with this method of quantification . This method can be used on coagulants of varying "r values" (r={OH-}/{Al3+}), or on mixtures of those coagulants and monomeric aluminium. Pest Manag Sci, 2002 Feb, 58(2), 146 - 60 Predicted impact of transgenic, herbicidetolerant corn on drinking water quality in vulnerable watersheds of the mid-western USA; Wauchope RD et al.; In the intensely farmed corn-growing regions of the mid-western USA, surface waters have often been contaminated by herbicides, principally as a result of rainfall runoff occurring shortly after application of these to corn and other crops . In some vulnerable watersheds, water quality criteria for chronic human exposure through drinking water are occasionally exceeded . We selected three settings representative of vulnerable corn-region watersheds, and used the PRZM-EXAMS model with the Index Reservoir scenario to predict corn herbicide concentrations in the reservoirs as a function of herbicide properties and use pattern, site characteristics and weather in the watersheds . We compared herbicide application scenarios, including broadcast surface pre-plant atrazine and alachlor applications with a glyphosate pre-plant application, scenarios in which losses of herbicides were mitigated by incorporation or banding, and scenarios in which only glyphosate or glufosinate post-emergent herbicides were used with corn genetically modified to be resistant to them . In the absence of drift, in almost all years a single runoff event dominates the input into the reservoir . As a result, annual average pesticide concentrations are highly correlated with annual maximum daily values . The modeled concentrations were generally higher than those derived from monitoring data, even for no-drift model scenarios . Because of their lower post-emergent application rates and greater soil sorptivity, glyphosate and glufosinate loads in runoff were generally one-fifth to one-tenth those of atrazine and alachlor . These model results indicate that the replacement of pre-emergent corn herbicides with the post-emergent herbicides allowed by genetic modification of crops would dramatically reduce herbicide concentrations in vulnerable watersheds . Given the significantly lower chronic mammalian toxicity of these compounds, and their vulnerability to breakdown in the drinking water treatment process, risks to human populations through drinking water would also be reduced. Water Res, 2002 Feb, 36(4), 891 - 8 Investigation of assimilable organic carbon (AOC) and bacterial regrowth in drinking water distribution system; Liu W et al.; This paper investigated the variation of assimilable organic carbon (AOC) concentrations in water from several typical water treatment plants and distribution systems in a northern city of China . It is concluded from this study that: (1) The AOC in most of the product water of the studied water treatment plants and the water from the associated distribution systems could not meet the biostability criteria of 50-100 microg/L . (2) Only 4% of the measured AOC concentrations were less than 100 microg/L . However, about half of the measured AOC values were less than 200 microg/L . (3) Better source water quality resulted in lower AOC concentrations . (4) The variation of AOC concentrations in distribution systems was affected by chlorine oxidation and bacterial activity: the former resulted in an increase of AOC value while the latter led to a reduction in AOC . (5) The variation of AOC concentration followed different patterns in different distribution systems or different seasons due to their respective operational characteristics . (6) Less than 30% of AOC could be removed by a conventional treatment process, whereas 30-60% with a maximum of 50-60% could be removed by granular activated carbon (GAC) . (7) The observation via scanning electron microscope (SEM) on distribution pipe tubercle samples demonstrated that the pipe inner wall was not smooth and bacteria multiplied in the crevice as well as in the interior wall of distribution pipes. Water Res, 2002 Feb, 36(4), 1095 - 101 Removal of organophosphate pesticides from wastewater by supercritical carbon dioxide extraction; Yu JJ; Organophosphate pesticides including fenitrothion chlorpyrifos, diazinon, methamidophos, edifenphos, mevinphos, fenthion, and acephate present in agro-wastewater can be effectively removed by supercritical carbon dioxide (SC-CO2) extraction . Near quantitative removal of the pesticides from the aqueous solution can be achieved by SC-CO2 at 90 degrees C and 325 atm for 20 min of static extraction followed by 40 min of dynamic extraction . The extracted pesticides were collected in a small amount of Fenton's solution . The pesticides in Fenton's solution were degraded completely within an hour after the collection . A combination of SC-CO2 extraction and subsequent degradation by Fenton's reagent may provide an alternative water purification strategy for treating organophosphate pesticides in agro-wastewater. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2002, 37(2), 273 - 85 Effect of operational conditions on membrane permeability in a coagulation-microfiltration process for water purification; Mo L et al.; A coagulation-microfiltration combination process was used in treatment of simulative surface water . The effects of operational conditions such as filtration time, ceasing time and aeration intensity on the membrane permeability and organic removals were investigated . Experiment results showed that the membrane permeability could be improved through changing the operational conditions . Decreasing the filtration time or increasing the ratio of filtration time/ceasing time was favorable to enhance the membrane permeability . As the aeration intensity increased, the membrane permeability was also enlarged to some extent, but was not improved obviously anymore when the aeration intensity was over the critical value of around 4m3h(-1) . Different wash methods to remove membrane fouling were attempted . The results suggested that coagulation in the process mainly led to change of the deposit cake-caused membrane fouling, which could be physically removed by surface wash . Organic removals, in terms of OC and UV254, apparently varied with the operational conditions . An inverse relationship between organic removals and membrane permeability was found . Lower membrane permeability led to higher OC and UV254 removals. Int J Food Microbiol, 2002 Jan 30, 72(1-2), 77 - 83 Antimicrobial effect of electrolyzed water for inactivating Campylobacter jejuni during poultry washing; Park H et al.; The effectiveness of electrolyzed (EO) water for killing Campylobacter jejuni on poultry was evaluated . Complete inactivation of C . jejuni in pure culture occurred within 10 s after exposure to EO or chlorinated water, both of which contained 50 mg/l of residual chlorine . A strong bactericidal activity was also observed on the diluted EO water (containing 25 mg/l of residual chlorine) and the mean population of C . jejuni was reduced to less than 10 CFU/ml (detected only by enrichment for 48 h) after 10-s treatment . The diluted chlorine water (25 mg/l residual chlorine) was less effective than the diluted EO water for inactivation of C . jejuni . EO water was further evaluated for its effectiveness in reducing C . jejuni on chicken during washing . EO water treatment was equally effective as chlorinated water and both achieved reduction of C . jejuni by about 3 log10 CFU/g on chicken, whereas deionized water (control) treatment resulted in only 1 log10 CFU/g reduction . No viable cells of C . jejuni were recovered in EO and chlorinated water after washing treatment, whereas high populations of C . jejuni (4 log10 CFU/ml) were recovered in the wash solution after the control treatment . Our study demonstrated that EO water was very effective not only in reducing the populations of C . jejuni on chicken, but also could prevent cross-contamination of processing environments. Environ Health Perspect, 2002 Feb, 110(2), 157 - 64 3-Chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and mutagenic activity in Massachusetts drinking water; Wright JM et al.; There is limited information on the prevalence of the potent mutagen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) in U.S . water supplies . We measured MX concentrations and mutagenic activity in tap water samples from 36 surface water systems throughout Massachusetts . We found MX levels much higher (up to 80 ng/L) than previously reported in the United States . We also evaluated the role of water treatment on mutagenic activity and disinfection by-product formation . After adjusting for other covariates, chloramination and filtration were the most important treatment options for reducing mutagenic activity and disinfection by-product formation . Multiple chlorine application (before and after filtration) was associated with increased mutagenicity . Chlorine dose, pH, and total organic carbon were also associated with mutagenicity, MX, and total trihalomethane (TTHM) concentration . Seasonal variation was evident for MX and mutagenic activity, with higher levels occurring in the spring compared to the fall . In contrast, TTHM concentrations were greater in the fall. Water Res, 2002 Feb, 36(3), 744 - 54 Laboratory study of ballasted flocculation; Desjardins C et al.; Ballasted flocculation is applied successfully in the water treatment industry, but the concept has not yet been subject to extended experimental studies . The use of a microsand and a polymer together to increase the weight of the flocs and the rate at which they settle is radically changing the coagulation flocculation-settling methodology . The objective of this research is to study ballasted flocculation in the laboratory by means of a modified jar-test procedure . The first tests, conducted using a statistical approach, enabled us to identify those parameters that have a significant influence on the quality of settled water . The principal treatment parameters considered in this study were the chemical dosage, the contact times in the different basins, the pH of coagulation and the dosage of microsand . The parameters used to evaluate the quality of the settled water, and hence treatment performances, were turbidity, UV absorbance, TOC and membrane filterability . The results showed that the coagulant dosage and the coagulation pH have a preponderant effect on the variability of the quality of the settled water . By contrast, filterability as measured by the laboratory filter tests, was found to be more sensitive to coagulant and microsand dosages . It was dependent on the ratio of microsand to polymer dosage, and improved when this ratio increased. Water Res, 2002 Feb, 36(3), 519 - 26 Prevalence of Cryptosporidium oocysts and giardia cysts in the drinking water supply in Japan; Hashimoto A et al.; A one-year monitoring of Cryptosporidium oocysts and Giardia cysts was conducted at a water purification plant . A total of 13 samples of 50 L river source water and 26 samples of 2,000 L-filtered water, treated by coagulation flocculation, sedimentation and rapid filtration, were tested . Prior to conducting a survey of a water purification plant, we developed a method for concentrating Cryptosporidium oocysts from a large volume of raw or filtered water using a hollow fiber ultrafiltration (UF) membrane, and this procedure was adapted to survey a water purification plant . Cryptosporidium oocysts were detected in all of the 13 raw water samples . The geometric mean concentration was 40 oocysts 100 L . Giardia cysts were detected in 12 of 13 raw water samples (92%) and the geometric mean concentration was 17 cysts/100 L . Probability distributions of both Cryptosporidium oocyst and Giardia cyst concentration in raw water were nearly lognormal . In filtered water samples, Cryptosporidium oocysts were detected in 9 of the 26 samples (35%) with the geometric mean concentration of 1.2 oocysts /1,000 L and Giardia cysts in 3 samples (12%) with 0.8 cysts/1,000 L . The estimated log10 removal efficiency of Cryptosporidium oocysts and Giardia cysts by rapid-sand filtration was 2.47 and 2.53, respectively . Empty particles were removed at a higher log10 than intact oocysts and cysts . The efficiency of particle removal in the rapid sand filtration process tends to be reduced under cold-water conditions . Close management is necessary in the winter when the water temperature is low. Water Res, 2002 Feb, 36(3), 511 - 8 Influence of the character of NOM on the ozonation of MIB and geosmin; Ho L et al.; Tastes and odours (T&Os) are a major concern in drinking water as they are not efficiently removed by conventional water treatment . Ozonation has been effective for their destruction in some studies . However, the natural organic matter (NOM) in waters can affect the ozonation process and subsequently affect the destruction of T&Os . Five NOM fractions were isolated and ozonated in synthetic waters . The fraction containing the more highly coloured, higher molecular weight compounds exhibited the highest ozone (O3) demand, whereas the low aromatic fraction exhibited the lowest O3 demand . The character of the NOM fractions influenced the ozonation of MIB and geosmin . The destruction of MIB and geosmin was significantly higher in the fraction with the highest colour and UV/visible absorbance at all O3 doses . The destruction of the compounds in the other fractions showed the same trends, increasing MIB and geosmin destruction with increasing UV/visible absorbing character of the NOM . MIB was also ozonated in two real waters . with results showing a competing effect between NOM concentration and NOM character . The O3 reaction time was shown to be important for the destruction of both compounds. J Chromatogr A, 2002 Jan 11, 943(1), 1 - 13 Determination of aldehydes in drinking water using pentafluorobenzylhydroxylamine derivatization and solid-phase microextraction; Cancho B et al.; A headspace solid-phase microextraction (HS-SPME) procedure followed by gas chromatography and electron capture detection (GC-ECD) has been developed for the determination of aldehydes in drinking water samples at microg/l concentrations . A previous derivatization with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) was performed due to the high polarity and instability of these ozonation by-products . Several SPME coatings were tested and the divinylbenzene-polydimethylsiloxane (DVB-PDMS) coating in being the most suitable for the determination of these analytes . Experimental SPME parameters such as selection of coating, sample volume, addition of salt, extraction time and temperature of desorption were studied . Analytical parameters such as precision, linearity and detection limits were also determined . HS-SPME was compared to liquid-liquid microextraction (proposed in US Environmental Protection Agency Method 556) by analyzing spiked water samples; a good agreement between results obtained with both techniques was observed . Finally, aldehydes formed at the Barcelona water treatment plant (N.E . Spain) were determined at levels of 0.1-0.5 microg/l . As a conclusion, HS-SPME is a powerful tool for determining ozonation by-products in treated water. Nefrologia, 2001 Jul-Aug, 21(4), 342 - 8 {Chronic dialysis in Uruguay: mortality trends from 1981 to 1998}}; Gonzalez C et al.; Uruguay is a developing country with 3.16 million inhabitants . Chronic dialysis treatment (CDT) expanded after the creation of a National Fund of Resources in 1980 who receives contribution from all inhabitants to finance, among others, the CDT and renal transplantation . During the 1981-1998 period, about 4,819 patients were treatment, 2,365 patients had died, 454 were transplanted and 51 patients were lost to follow-up due to change in residence . At the start of the treatment, mean age was 57.0 +/- 17.7 years, 37% were 65 or older than 65 year old, 61.3% were male and 98% of patients were white persons . The most common diseases responsible for End Stage Renal Disease were: hypertension (22%), chronic glomerulonephritis (19%) and diabetic nephropathy (15%) . In 1998, there were 44 dialysis units in the country (13.6 units per million population--pmp), 100% of them had water treatment (reverse osmosis 96.8%) and reuse dialyzer . The most frequent causes of death were: cardiovascular and infection . In this paper, eighteen years of the mortality time course of CDT are analyzed . Annual mortality rate was expressed as deaths per 1,000 patients years at risk (M/1,000) . The indirect standardization method was applied to adjust the mortality rate . Two populations were used as standard: the 1996 population of USRDS to adjust for age, sex, race and nephropathy and the 1996 Uruguayan general population to adjust for age . Standardized mortality rate (SMR) for each year was obtained dividing observed deaths by expected deaths . From 1981 to 1998, the incident population increased from 32 to 133 patients per million populations and the prevalent population from 28 to 639 pmp . There was a simultaneously increase in the prevalence of diabetic patients and of patients older than 65 years . The annual mortality rate decreased from 249 to 138 deaths per 1,000 patient years (M/1,000) . The standardized mortality (SM) with the USRDS population as standard decreased from 452 in 1981 to 132 in 1998 and the SMR from 2.07 to 0.60 . The SMR with the Uruguayan general population decreased from 17 to 4 . In conclusion, these results are similar with those observed in developed countries . There has been a decrease both in the gross and the standardized mortality ratio in the period of observation. Toxicol Sci, 2002 Feb, 65(2), 177 - 83 Acrylamide-induced cellular transformation; Park J et al.; Acrylamide is a monomer of polyacrylamide, whose products are used in biochemistry, the manufacture of paper, water treatment, and as a soil stabilizer . While polymeric acrylamide is nontoxic, the monomer can cause several toxic effects and has the potential for human occupational exposure . While acrylamide is not mutagenic in prokaryotic mutagenesis assays, chronic acrylamide treatment in rodents has been shown to produce tumors in both rats and mice . The mechanism for the induction of tumors by acrylamide is not known . In the present study, we examined the possibility that acrylamide might induce cellular transformation, using Syrian hamster embryo (SHE) cell morphological transformation as well as potential mechanisms for the cellular transformation . Results showed that treatment with 0.5 mM and higher concentrations of acrylamide continuously for 7 days induced morphological transformation . Cotreatment with acrylamide and N-acetyl-L-cysteine (NAC), a sulfhydryl group donor, resulted in the reduction of acrylamide-induced morphological transformation in SHE cells . Cotreatment with 1-aminobenzotriazole (ABT), a nonspecific P450 inhibitor, and acrylamide produced no change in morphological transformation when compared to acrylamide treatment only . Cotreatment with acrylamide and DL-buthionone-{S,R}-sulfoximine (BSO), a selective inhibitor of gamma-glutamylcysteine synthetase, increased the percent of morphologically transformed colonies compared to acrylamide treatment alone . Acrylamide reduced GSH levels in SHE cells, and cotreatment with acrylamide and NAC prevented the acrylamide-induced reduction of GSH . BSO treatment with acrylamide enhanced the depletion of GSH . These results suggest that acrylamide itself, but not oxidative P450 metabolites of acrylamide appear to be involved in acrylamide-induced cellular transformation and that cellular thiol status (possibly GSH) is involved in acrylamide-induced morphological transformation. J Appl Toxicol, 2002 Jan-Feb, 22(1), 31 - 5 In vitro hepatotoxicity of alachlor and its by-products; El-Sakka S et al.; During water treatment, potentially hazardous chemical by-products may be formed . Alachlor (2-chloro-N-(2, 6-diethylphenyl)-N-(methoxymethyl) acetamide) is a widely used pre-emergence herbicide . The present study investigated the toxicity of alachlor and its disinfection by-products on freshly isolated rat hepatocytes . Hepatocytes were harvested by a collagenase perfusion technique and were exposed to different concentrations of alachlor and its by-products for up to 2 h . Cell viability, the leakage of aspartate transaminase (AST) and alanine transaminase (ALT) and glutathione (GSH) depletion were determined throughout the incubation period . The cell viability of the hepatocytes exposed to 100 microg ml(-1) alachlor was decreased by 20% compared with the control after 60 min of incubation . At the same concentration of alachlor the leakage of ALT and AST was increased by 56% and 45%, respectively . Cell viability of the hepatocytes was decreased upon exposure to 2-chloro-N-(3-chloro-2,6-diethylphenyl)-N-(methoxymethyl) acetamide (CCDMA) and 2-chloro-N-(3-chloro-2,6-diethylphenyl) acetamide (CCDA)--the by-products of alachlor and chlorine--after 60 min of exposure . At 100 microg ml(-1) CCDMA the AST leakage was increased significantly (73%) after 30 min of incubation . The reaction mixture of alachlor (100 microg ml(-1)) and chlorine dioxide (1 ppm) caused significant increases in cell loss and ALT and AST levels by 22%, 40% and 34%, respectively, as early as 15 min incubation . Alachlor (100 and 200 microg ml(-1)) caused significant decreases in GSH contents (62%) in isolated hepatocytes . The reaction mixture of alachlor and chlorine dioxide led to significant glutathione depletion (44%) after 60 min of incubation . The by-products of alachlor and chlorine--CCDMA and CCDA--depleted GSH almost completely (93%) . This investigation suggested that the by-products formed from the reaction of alachlor and chlorine decreased GSH and increased the leakage of liver enzymes, especially AST . Chemosphere, 2002 Jan, 46(1), 109 - 13 Ozonation of hydrolyzed azo dye reactive yellow 84 (CI); Koch M et al.; The combination of chemical and biological water treatment processes is a promising technique to reduce recalcitrant wastewater loads . The key to the efficiency of such a system is a better understanding of the mechanisms involved during the degradation processes . Ozonation has been applied to many fields in water and wastewater treatment . Especially for textile mill effluents ozonation can achieve high color removal, enhance biodegradability, destroy phenols and reduce the chemical oxygen demand (COD) . However, little is known about the reaction intermediates and products formed during ozonation . This work deals with the degradation of hydrolyzed Reactive Yellow 84 (Color Index), a widely used azo dye in textile finishing processes with two monochlorotriazine anchor groups . Ozonation of the hydrolyzed dye in ultra pure water was performed in a laboratory scale cylindric batch reactor . Decolorization, determined by measuring the light absorbance at the maximum wavelength in the visible range (400 nm), was almost complete after 60 and 90 min with an ozone concentration of 18.5 and 9.1 mg/l, respectively . The TOC/TOC0 ratio after ozonation was about 30%, the COD was diminished to 50% of the initial value . The BOD5/COD ratio increased from 0.01 to about 0.8 . Oxidation and cleavage of the azo group yield nitrate . Cleavage of the sulfonic acid groups of aromatic rings caused increases in the amount of sulfate . Formic acid and oxalic acid were identified as main oxidation products by high performance ion chromatography (HPIC) . The concentrations of these major products were monitored at defined time intervals during ozonation. Water Sci Technol, 2001, 44(11-12), 493 - 8 The effect of refinery effluent on the aquatic macrophytes Scirpus californicus, Typha subulata and Zizaniopsis bonariensis; Campagna AR et al.; Experimental wetlands were built to follow the implementation and permanence of three species of aquatic macrophytes (Scirpus californicus, Typha subulata and Zizaniopsis bonariensis) under different treatments (water, water + nutrients and water+ nutrients + refinery effluent) . Morphological variables (number of lateral shoots produced, height of the main lateral shoot and final density values) were used to check the influence of a petrochemical effluent . All the response variables showed significant differences (p = 5%) in their development, mainly between the water treatment and water + nutrient + effluent, followed by water with water + nutrients . In the Water treatment, the lowest variable values were found for the three species, possibly due to the lack of nutrients in the medium . Opposite results were found in the other treatments, indicating that the petrochemical effluent was not a limiting factor for the implementation of the species in the systems. Environ Int, 2001 Dec, 27(6), 495 - 519 Combinatorial bio/chemical analysis of dioxin and dioxin-like compounds in waste recycling, feed/food, humans/wildlife and the environment; Behnisch PA et al.; The present review describes international activities using bioassays/biomarkers in combination with chemical analysis to measure the effects of dioxin and dioxin-like compounds (DLCs) in the environment . The above authors reviewed already the state-of-art bioanalytical detection methods (BDMs) for dioxins and DLCs {Environ Int (2001)} . The aim of this study will be to review applications of these bioassays/biomarkers to evaluate potential dioxins and DLCs . The present literature study lists relative potencies (REPs) of polyhalogenated dibenzo-p-dioxins and -furans (PXDD/Fs; X = Cl, Br, F), their thio analogues polychlorinated dibenzothiophenes (PCDTs) and thianthrens (PCTAs), polyhalogenated biphenyls (PXBs), polychlorinated naphthalenes (PCNs) and other Ah receptor agonists measured by several biodetectors (Tier 3 screening) . The authors will discuss some examples of the applications of some of these biodetectors in biomonitoring programmes and recently occurred dioxin crisis in feed/food . The diagnosis of the biopotency of these pollutants in technical processes like thermally treated waste, waste water treatment, landfill leachate treatment, commercial PCB-mixtures, the release into the environment (soil, air and water) and the final intake into wildlife and humans will be reviewed. Fed Regist, 2002 Jan 14, 67(9), 1811 - 44 National primary drinking water regulations: Long Term 1 Enhanced Surface Water Treatment Rule . Final rule; Environmental Protection Agency (EPA); In this document, EPA is finalizing the Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR) . The purposes of the LT1ESWTR are to improve control of microbial pathogens, specifically the protozoan Cryptosporidium, in drinking water and address risk trade- offs with disinfection byproducts . The rule will require systems to meet strengthened filtration requirements as well as to calculate levels of microbial inactivation to ensure that microbial protection is not jeopardized if systems make changes to comply with disinfection requirements of the Stage 1 Disinfection and Disinfection Byproducts Rule (DBPR) . The LT1ESWTR applies to public water systems that use surface water or ground water under the direct influence of surface water and serve fewer than 10,000 persons . The LT1ESWTR builds upon the framework established for systems serving a population of 10,000 or more in the Interim Enhanced Surface Water Treatment Rule (IESWTR) . This rule was proposed in combination with the Filter Backwash Recycling Rule (FBRR) in April 2000. Fresenius J Anal Chem, 2001 Dec, 371(8), 1124 - 9 Coupling pervaporation to AAS for inorganic and organic mercury determination . A new approach to speciation of Hg in environmental samples; Fernandez-Rivas C et al.; The design and development of a new approach for Hg speciation in environmental samples is described in detail . This method, consisting of the coupling of pervaporation and atomic absorption spectrometry, is based on a membrane phenomenon that combines the evaporation of volatile analytes and their diffusion through a polymeric membrane . It is proposed here as an alternative to gas chromatography for speciation of inorganic and organic Hg compounds, as the latter compounds are volatile and can be separated by applying the principles mentioned above . The interest of this method lies in its easy handling, low cost, and rapidity for the analysis of liquid and solid samples . This method has been applied to Hg speciation in a compost sample provided by a waste water treatment plant. Antimicrob Agents Chemother, 2002 Feb, 46(2), 420 - 4 Protective efficacy of a sulfated sialyl lipid (NMSO3) against human rotavirus-induced diarrhea in a mouse model; Takahashi K et al.; Antiviral activity of sulfated sialyl lipid (NMSO3) against human rotavirus (RV) was examined in vitro and in vivo . NMSO3 inhibited the replication of four major serotypes (G1 to G4) of human rotavirus with a low 50% effective concentration of 1 to 5 microg/ml and 50% cytotoxic concentration of 153 microg/ml when determined by plaque assays with MA104 cells . Exposure of NMSO3 to HCl (pH 2.0) for 30 min exhibited no loss of anti-RV activity . Time-of-addition experiments revealed that NMSO3 inhibited the adsorption of four serotypes of RV to MA104 cells . Furthermore, an assay of virus binding with radiolabeled RVs revealed that NMSO3 inhibited the binding of virus to MA104 cells, suggesting that NMSO3 may bind to VP4 and/or VP7 . Prophylactic oral administration of NMSO3 (10 microg three times per day, 4 days) to five suckling mice starting 30 min before inoculation of MO strain (3 x 10(6) PFU/mouse) prevented the development of diarrhea . Four of five mice showed no stool or brown formed stool, and only one mouse showed brown soft stool, while water treatment caused watery diarrhea in all five mice . The mean titer of antibody to RV in mice which received NMSO3 at 10 microg three times per day for 4 days was significantly lower than that of untreated, infected mice . NMSO3 is a promising candidate for the prophylactic treatment of human RVs. Water Sci Technol, 2001, 44(10), 321 - 5 Sludge dewatering using centrifuge with thermal/polymer conditioning; Lin CF et al.; Sludge dewatering is preceded by a conditioning operation to enhance water removal efficiency . In the conditioning operation, chemical coagulants or polymers are added to promote sludge particle aggregation for easier dewatering . In this study, an alternative conditioning method for sludge thermal treatment at temperatures up to 80 degrees C was extensively investigated . Dewatering characteristics such as sludge capillary suction time and specific resistance to filtration, sludge viscosity and concentration of solid cakes were examined thoroughly . A good correlation between capillary suction time and specific resistance to filtration was established for sludges from water treatment, but not for biological sludge . Cationic polymer exhibits the best enhancement on sludge moisture removal . The sludge rheogram varies from 60 to 5 cP as temperature changes from 20 to 80 degrees C for sludges from water treatment plant . The dewatering ability of sludge can be greatly enhanced by thermal treatment in conjunction with the use of polymers. Water Sci Technol, 2001, 44(10), 273 - 7 Reuse of water treatment plant sludge and dam sediment in brick-making; Huang C et al.; In this study, an attempt was made to use water treatment plant (WTP) sludge and dam sediment as raw materials for brick-making through the sintering process . The sinter of dam sediment fired at 1,050 degrees C had a less than 15% ratio water absorption, and its compressive strength and bulk density met the Chinese National Standard (CNS) for first level brick . The WTP sludge sinter made under the same operating condition exhibited higher water absorption, larger shrinkage, but poorer compressive strength . When fired at 1,100 degrees C, the shrinkage of the WTP sludge sinter was as high as 45%, although its compressive strength and water absorption of WTP sludge brick still met the standard for the first level brick . To reuse WTP sludge in an economical way, mixtures of various proportions of WTP sludge to dam sediment are used as raw materials . A satisfactory result was achieved when the ratio of the WTP sludge was less than 20% of the mixture . Results of tests indicated that the sinter of dam sediments which are fired at a temperature of 1000 to approximately 1100 degrees C has reached the requirement for tile brick. Water Sci Technol, 2001, 44(10), 231 - 6 Properties of flocs produced by water treatment coagulants; Gregory J et al.; Hydrolyzing coagulants are extensively used in water and wastewater treatment, often under conditions where hydroxide precipitation is important, giving "sweep flocculation" . Pre-hydrolyzed coagulants, such as polyaluminium chloride (PACl) are also widely used and have several advantages over traditional additives, such as aluminium sulfate . Their action is usually discussed in terms of cationic species and charge neutralization . However, precipitation may also be important and this aspect has not been considered in detail . The present work has compared the action of alum and three commercial PACl products on model clay suspensions . The conventional jar test procedure has been used, along with measurements of settled floc volume and dynamic monitoring of floc formation and break-up by an optical technique . The latter method gives very useful information on the nature of the flocs produced and their response to different shear conditions . It is clear from the results that the PACl products form larger and stronger flocs than alum . With all coagulants floc breakage appears to be essentially irreversible . Sediment volumes are slightly lower for flocs produced by PACl than by alum, but the value is proportional to the dosage in all cases. Water Res, 2001 Dec, 35(17), 4126 - 36 Biodegradation of anthracene and fluoranthene by fungi isolated from an experimental constructed wetland for wastewater treatment; Giraud F et al.; Pilot-scale constructed wetlands were used to treat water contaminated by polycyclic aromatic hydrocarbons (PAHs), particularly fluoranthene, and the possible role of fungi present in these ecosystems was investigated . A total of 40 fungal species (24 genera) were isolated and identified from samples (gravel and sediments) from a contaminated wetland and a control wetland . All of them were assayed for their ability to remove anthracene (AC) and fluoranthene (FA) from liquid medium . FA was degraded efficiently by 33 species while only 2 species were able to remove AC over 70% . A selection of 10 strains of micromycetes belonging to various taxonomic groups was further investigated for FA and AC degradation, toxicity assays and phenoloxidases (POx) detection . Interesting and not previously reported species were revealed (Absidia cylindrospora, Cladosporium sphaerospermum, and Ulocladium chartarum) . They were all able to highly degrade the PAH-model compounds chosen . An interesting inducibility was noted for Ulocladium chartarum . Degradative ability of fungi was not related to their extracellular POx activity . This study may contribute to the improvement of constructed wetlands for water treatment, which may be enriched in efficient fungi. Anal Chem, 2001 Dec 15, 73(24), 5886 - 95 Simultaneous determination of halogenated derivatives of alkylphenol ethoxylates and their metabolites in sludges, river sediments, and surface, drinking, and wastewaters by liquid chromatography-mass spectrometry; Petrovic M et al.; A quantitative solid-phase extraction-liquid chromatography/mass spectrometry (SPE-LC/MS) method is described for the simultaneous analysis of halogenated byproducts of alkylphenolic compounds and their degradation products formed during chlorine disinfection in the presence of bromide ions . Compounds analyzed include brominated and chlorinated nonylphenol ethoxylates (XN-PEOs); octylphenol ethoxylates (XOPEOs); nonylphenols (XNP); nonylphenoxycarboxylates (XNPECs) and their precursors nonionic surfactants, alkylphenol ethoxylates (APEOs); and their metabolites formed during sewage treatment, alkylphenoxycarboxylates (APECs) and alkylphenols (APs) . Target compounds were concentrated from water samples using a C18 SPE procedure . Extracts were analyzed using reversed phase LC/MS . The performances of both atmospheric pressure chemical ionization (APCI) and electrospray (ESI) interfaces were compared . ESI offered better sensitivity and specificity for a higher range of oligomers . Detection limits (LODs) for water samples were from 20 to 100 ng/L; and for sediment samples, from 2 to 10 microg/kg . Slightly higher LODs were obtained for sludge samples (5-25 microg/kg) . Halogenated byproducts were found in sludge from Barcelona drinking water treatment plant in concentrations of 220 microg/kg for BrNP, 430 microg/kg for BrNPEOs (nEO = 1 - 2), and 1600 microg/kg for BrNPEOs (nEO = 3 - 15) . The concentration of ClNPEOs was estimated to be in the order of 660 microg/kg (assuming the same response as BrNPEOs) . Halogenated OPEOs were also identified, and their concentration was approximately 50 times lower than the concentration of NPEOs analogues . To our knowledge, this is the first method described that allows simultaneous determination of alkyphenol ethoxylates and halogenated derivatives, including degradation products. J Environ Monit, 2001 Dec, 3(6), 621 - 6 Occurrence of organophosphate esters in surface water and ground water in Germany; Fries E et al.; The present investigation was carried out to quantify the three organophosphate esters, tributyl phosphate (TBP), tris(2-chloroethyl) phosphate(TCEP) and tris(2-butoxyethyl) phosphate(TBEP), in river, rain and ground water obtained from several locations in Germany, and to compare the data with those obtained about 15 years ago . Additionally, one influent and one effluent sample of waste water from a local waste water treatment plant were investigated . The applied analytical method is based on solid phase extraction (SPE), in order to concentrate polar compounds from water samples, followed by gas chromatography-mass spectrometry (GC-MS) of the extracts . A total of 5 1 of the respective water samples was used for extraction purposes and analyte recoveries were all > or = 83% . The detection limit for the target analytes was 1 ng l(-1) and the relative standard deviations for replicate injections (n = 10) were 14.0% for TBP, 12.6% for TCEP and 9.9% for TBEP . The presence of the organophosphorus compounds, TBP, TCEP and TBEP, in Germany has resulted in water concentrations of 17-1,510 ng l(-1) in the Rhine, Elbe, Main, Oder, Nidda and Schwarzbach Rivers . The maximum value of TBP measured in the Rhine River was 17 times lower than the maximum value measured 10 years ago . The maximum value of TCEP measured in the Rhine River was 100 times lower than the maximum value measured in previous investigations . The maximum concentration of TBEP measured in the Elbe River was seven times higher than the value measured 16 years ago . Similar concentrations of TBP, TCEP and TBEP were also detected in ground water and rain water . The highest levels of these compounds were detected in samples of waste water. Environ Sci Technol, 2001 Dec 15, 35(24), 4697 - 703 Removal of endocrine-disrupting chemicals in activated sludge treatment works; Johnson AC et al.; The release of endocrine-disrupting chemicals into the aquatic environment has raised the awareness of the central role played by sewage treatment in lowland water quality . This review focuses on the activated sludge process, which is commonly used to treat sewage in large towns and cities and which successfully removes the bulk of the organic compounds that enter the works . However, not all compounds are completely broken down or converted to biomass . For example, the estrogenic alkylphenols and steroid estrogens found in effluent are the breakdown products of incomplete breakdown of their respective parent compounds . Batch microcosm studies have indicated that estrone, ethinylestradiol, and alkylphenols will not be completely eliminated in activated sludge over typical treatment times . Field data suggest that the activated sludge treatment process can consistently remove over 85% of estradiol, estriol, and ethinylestradiol . The removal performance for estrone appears to be less and is more variable . Because of its relatively high hydrophobicity, the accumulation of alkylphenol in sludge has been observed . Although it has not been examined, accumulation of ethinylestradiol in sludge is a possibility due to its recalcitrance and hydrophobicity . A comparison between the concentrations of some of the major endocrine-active chemicals in effluents and their biological potencies has been made, to direct attention to the chemicals of most concern . While water purification techniques such as UV or activated charcoal could significantly remove these microorganic contaminants, the high costs involved suggest that research into the potential for treatment optimization should receive more attention. Clin Infect Dis, 2002 Feb 1, 34(3), 355 - 64 Epub 2001 Dec 17. Water disinfection for international and wilderness travelers; Backer H; Acquisition of waterborne disease is a substantial risk for international travelers to countries with inadequate sanitation facilities . It also poses smaller but still significant risks for wilderness travelers who rely on surface water in developed countries with low rates of diarrheal illness, such as the United States . This article reviews the etiology and risks associated with waterborne disease that might be encountered by both types of travelers . It also summarizes--and makes recommendations for--the various water-treatment methods available to travelers for reducing their risk of contracting waterborne disease. J Chromatogr A, 2001 Dec 14, 938(1-2), 45 - 55 Determination of haloacetic acids in aqueous environments by solid-phase extraction followed by ion-pair liquid chromatography-electrospray ionization mass spectrometric detection; Loos R et al.; Haloacetic acids (HAAs) were determined in different water samples by a new, fast and simple analysis method based on enrichment of 50-ml water samples at pH 1.8 by solid-phase extraction (SPE) followed by liquid chromatography (LC) separation and electrospray ionization mass spectrometric detection in the negative ionization mode . Deprotonated (M-H)-haloacetates and decarboxylated (M-COOH)- ions were detected . Different polymeric SPE sorbents were tested, and LiChrolut EN was found to be the best material for the extraction . Complete LC separation of all compounds could only be achieved by ion-pair chromatography using triethylamine as volatile ion-pairing reagent . The detection limits were in the low microg/l range . High microg/l concentration levels for the chlorinated and brominated haloacetates were found in drinking water from a drinking water treatment plant in Barcelona, and the corresponding tap water . In swimming pool water samples from Catalonia mg/l levels and in surface river water from Portugal microg/l values were detected . These results confirm other recent reports on the ubiquitous occurrence of HAAs in aqueous environments. Water Res, 2002 Jan, 36(1), 140 - 6 Degradation of microcystin toxins in a falling film photocatalytic reactor with immobilized titanium dioxide catalyst; Shephard GS et al.; The increasing incidence of algal blooms in fresh water supplies and the consequent possibility of cyanobacterial microcystin contamination of potable water is a cause of recent concern . Heterogeneous photocatalytic oxidation forms part of a family of advanced water treatment technologies comprising the generation of reactive oxidizing species in water media and results in the complete oxidative degradation (mineralization) of organic pollutants to yield carbon dioxide, water and inorganic ions . A new experimental laboratory-scale 'falling film' reactor has been developed to study the photocatalytic degradation of microcystins in aqueous solution . The reactor consisted of a fiberglass sheet impregnated with immobilized titanium dioxide (TiO2) catalyst over which the microcystin solution was pumped (as a falling film) while being irradiated from UV-C germicidal lamps . The design of the system obviated the necessity to separate suspended catalyst from treated water as required in slurry reactors . The photocatalytic degradation was characterized by pseudo-first order reaction kinetics . Rapid degradation of microcystins LR, YR and RR was observed in natural lake water with half lives less than 10 min, while even faster rates were achieved in laboratory distilled water . Although low pH (pH 3) marginally improved reaction rates . the presence of radical scavengers such as sulfate ions was detrimental to the photocatalytic oxidation process. Water Res, 2002 Jan, 36(1), 330 - 42 Development of chlorine dioxide-related by-product models for drinking water treatment; Korn C et al.; Factorial experiments were conducted using source waters from seven drinking water treatment plants in Ontario, Canada to develop statistically based model equations capable of predicting chlorine dioxide consumption and chlorite and chlorate formation upon chlorine dioxide application . The equations address raw water quality and operational parameters including pH, temperature, chlorine dioxide concentration, reaction time and water organic content (as described by non-purgeable organic carbon x ultraviolet absorbance measured at 254 nm, NPOC x UV254) . Terms describing two-factor interaction effects were also included, improving the accuracy of the predictive equations in fitting measured response concentrations as evaluated through internal and external validations . Nearly 80% of the predictions for chlorine dioxide consumption and chlorite formation were observed to be within 20% of the measured levels . Over 90% of the predicted chlorate levels were within +/- 0.1 mg/L of the measured levels . Chlorine dioxide concentration and NPOC x UV254 were key parameters when developing the predictive models. Water Res, 2001 Dec, 35(18), 4464 - 73 The impact of ferrous ion reduction of chlorite ion on drinking water process performance; Henderson R et al.; The use of chlorine dioxide (ClO2) as a primary disinfectant and pre-oxidant in drinking water treatment is being explored as an alternative to chlorine for reducing disinfection by-product formation and to assure compliance with United States Environmental Protection Agency's Stage 1 Disinfection/ Disinfection By-Products Rule . However, the ClO2 by-product chlorite ion (ClO2-) is also regulated by the same regulation . Ferrous iron (Fe(II)) has been shown to effectively reduce chlorite ion to chloride ion (Cl-) and this study was conducted to evaluate the impact on overall treatment process performance due to the ferric hydroxide solids that form from the reaction . Ferrous iron application was explored at three different points in a pilot-scale water treatment system: pre-rapid mix . pre-settling and pre-filter . Chlorite ion concentrations were effectively reduced from 2mg/L to less than 0.3mg/L using an Fe(II) dose of approximately 6mg/L for all trials . Fe(II) addition at the rapid mix caused no adverse effects and, in fact, allowed for reduction of the alum dose due to the newly formed ferric hydroxide acting as a supplemental coagulant . An increase of 241 and 247% of total suspended solids influent to the filter process was observed when Fe(II) was applied at the pre-settling and pre-filter locations . Pilot-scale filter runs during these trials were less than 2 h and never obtained true steady state conditions . Jar testing was performed to better understand the nature of the ferric hydroxide solids that are formed when Fe(II) was oxidized to Fe(III) and to explore the effectiveness of Fe(II) addition at intermediate stages in the flocculation process. Water Res, 2001 Dec, 35(18), 4455 - 63 Influence of the characteristics of natural organic matter on the fouling of microfiltration membranes; Fan L et al.; Natural organic matter (NOM) plays a significant role in fouling microfiltration membranes in drinking water treatment processes even though the NOM is retained only to a small extent . The aim of this study was to obtain a better understanding of the interactions between the fractional components of NOM and microfiltration membranes . Filtration experiments were performed using 0.22 microm hydrophobic and hydrophilic polyvinylidene fluoride (PVDF) membranes in a stirred-cell system on the NOM isolated from three Australian surface waters . As expected, the fouling rate for the hydrophobic membrane was considerably greater than for the hydrophilic membrane . Focusing on the hydrophobic membrane, it was shown that the high molecular weight fraction of NOM ( > 30 kDa) was responsible for the major flux decline . Filtration tests on the four fractions of NOM isolated on the basis of hydrophobicity and charge using non-functionalised and anionic resins revealed that the fouling potential for the three waters was hydrophilic neutral > hydrophobic acids > transphilic acids > hydrophilic charged . The low-aromatic hydrophilic neutral compounds were the main determinant of the rate and extent of flux decline . This was linked to the colloidal size fraction ( > 30 kDa) and to the selective concentration of calcium in the fraction leading to organics-Ca2+ bridging . It was also shown that the higher the aromaticity of the NOM the greater the flux decline, and the aromatics mainly resided in the hydrophobic acids fraction . Overall, the fouling mechanism controlling the flux decline involved the combined effects of adsorptive and colloidal fouling by the hydrophilic neutral fraction in the internal pore structure of the membrane. Water Res, 2001 Dec, 35(18), 4444 - 54 Assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC): complementary measurements; Escobar IC et al.; The objective of this study was to evaluate the necessity of measuring both assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC) as indicators of bacterial regrowth potential . AOC and BDOC have often been measured separately as indicators of bacterial regrowth, or together as indicators of bacterial regrowth and disinfection by-product formation potential, respectively . However, this study proposes that both AOC and BDOC should be used as complementary measurements of bacterial regrowth potential . In monitoring of full-scale membrane filtration, it was determined that nanofiltration (NF) removed over 90% of the BDOC while allowing the majority of the AOC through . Heterotrophic plate counts (HPC) remained low during the entire period of monitoring due to high additions of disinfectant residual . In a two-year monitoring of a water treatment plant that switched its treatment process from chlorination to chlorination and ozonation, it was observed that the plant effluent AOC increased by 127% while BDOC increased by 49% after the introduction of ozone . Even though AOC is a fraction of BDOC, measuring only one of these parameters can potentially under- or overestimate the bacterial regrowth potential of the water. Water Res, 2001 Dec, 35(18), 4426 - 34 Membrane and solution effects on solute rejection and productivity; Zander AK et al.; Limited understanding of the physical and chemical processes involved in membrane processes affects their widespread application in drinking water treatment . Insight into these processes was attained through a systematic manipulation of solution chemistry in membrane filtration with three 'loose' nanofiltration membranes . Eighteen known solutions were created varying pH, ionic strength, and major cation valence in the presence of a commercial humic acid . The membrances varied as well, including a non-ionic hydrophobic, a non-ionic hydrophilic, and an anionic hydrophilic membrane surface . Specific membrane productivity and TOC and conductivity rejection were monitored . In all cases, the presence of divalent cations decreased the rejection of both conductivity and organic matter . Divalent cations also greatly increased the rate of productivity decline over equivalent tests in solutions with monovalent cations . The most hydrophobic membrane had the greatest productivity decline rate under all solution conditions . The lowest ionic strength solutions showed the greatest TOC and conductivity rejection and the greatest rate of productivity decline for each of the membranes. Water Res, 2001 Dec, 35(18), 4253 - 60 Photochemical processes for atrazine degradation: methodological approach; Hequet V et al.; Numerous studies have been carried out on s-triazines, and more specifically on atrazine, with the long-term objective of resolving the problems caused by these herbicides: removing them from drinking water . However, applications have remained too limited . So far, processes based on photochemical degradation have been little implemented . We, therefore, investigated the development of photochemical processes, emphasizing their capacity to degrade triazine by photolytic and photocatalytic mode . The study sought to assess the performance of these ssstems . Experiments ts showed that according to a medium pressure mercury source (UV-Vis irradiation), the photolytic degradation of atrazine was very efficient, with a best atrazine degradation half-life shorter that 5 min . The main degradation pathway was deshalogenation . The photocatalytic degradation of atrazine under irradiation over 290 nm in the presence of titanium dioxide was shown to be efficient too, with a half-life of about 20 min . In this case an experimental design was conducted so as to assess the influence of various parameters: pH, water medium, and amount of catalyst . There has been observational evidence for the efficiency of the processes investigated here and for potential technological developments as regards drinking water treatment. Water Sci Technol, 2001, 44(9), 173 - 80 Combination of advanced oxidation processes and gas absorption for the treatment of chlorinated solvents in waste gases; Dewulf J et al.; Treatment of chlorinated organic compounds in waste gases is difficult because of several reasons: these compounds are dioxin precursors when incinerated, and also biological treatment is difficult because of a limited number of suitable microbial degradation pathways . On the other hand, since the 1990s, a new generation of chemical oxidation techniques has been introduced in water treatment . Advanced Oxidation Processes (AOPs) are based on a combination of UV/H202, UV/O3 or H2O2/O3 . The combinations result in the generation of OH-radicals, which subsequently attack the organic pollutants . In this work, the treatment of a gas stream (240 L/h) loaded with 20-40 ppmv trichloroethylene (TCE) is presented . Therefore, a combination of an absorption process in a bubble column with a liquid H2O2/O3 initiated oxidation, was investigated . Removal efficiencies, depending on the dosed H2O2 and O3, up to 94% were found . The production of chloride ions was investigated: the Cl-atoms from the removed TCE could be found back as chloride ions . Next to the experimental work, attention was paid to the mechanisms taking place in the proposed concept . Here, a simulation model was developed, considering gas/liquid mass transfer of TCE and ozone, axial liquid dispersion, advective gas and liquid transport and about 29 chemica reaction steps . The modelling allowed a better understanding of the technique and gives insight in its possibilities and limitations . Finally, it can be concluded that the proposed technique shows interesting perspectives: it is able to transform chlorine in chlorinated solvents into chloride ions effectively at ambient temperature conditions. Mar Pollut Bull, 2001 Jul-Dec, 43(7-12), 187 - 208 A new coastal marine ecosystem model study coupled with hydrodynamics and tidal flat ecosystem effect; Sohma A et al.; A new coastal marine ecosystem model was developed, which was composed of pelagic and benthic ecosystems, and was applied to Mikawa Bay, Japan . This model deals with variations of biochemical and physical interactions among dissolved oxygen and C-N-P species (composition formed out of carbon, nitrogen and phosphorus elements) so that it resolves the flux dynamics of carbon, nitrogen, phosphorus and oxygen elements . The physical and biochemical mechanism figured in this model is constructed for the purpose of simulating the estuarine lower trophic ecosystem, in areas where the sea was too deep for light to reach the sea-bottom . As a result of coupling the benthic with pelagic system, the effect of process of sedimentation and nutrient diffusion back to the pelagic system could be indicated . In addition, by implementing the tidal flat ecosystem model's calculation result, the integrated model can include the effect of water purification in tidal flats where the light can reach the sea-bottom, and where seaweed, sea grass and benthic algae exist . In this study, the model indicates that oxygen-depleted water exists at the sea-bottom especially in summer mainly caused by an increase of oxygen consumption in the benthic system and a decrease of the vertical mixing water process . Furthermore, by comparing the case--with the tidal flat ecosystem model and the case without it, the effect of water purification of tidal flat estuaries was indicated . From the viewpoint of a short time scale, the tidal flat has the potential to restrict red tide (rapid increase of phytoplankton), and from the viewpoint of a long time scale, it restricts the sedimentation of detritus . Restricting the sedimentation prevents oxygen-depleted water occurring in the coastal marine system of Mikawa Bay. J Environ Sci Health A Tox Hazard Subst Environ Eng, 2001, 36(10), 1983 - 96 Rheological behavior of Phanerochaete chrysosporium broth during lignin degradation; Hernandez-Penaranda AM et al.; Rheological behavior of a lignin-degrading culture of Phanerochaete chrysosporium CDBB-H-298 was determined . Rheological characteristics revealed a Newtonian behavior in the culture medium without fungi, and a non-Newtonian dilatant behavior with fungi . In addition, the rheological behavior of the lignin-containing culture medium was complex, and changed from dilatant to pseudoplastic . During fungal growth without lignin in Kirk media rheological behavior exhibited a parabolic profile, and thixotropy showed a tendency to increase . Results indicated a small increase in the apparent viscosity in the presence of lignin; however, this may not affect the oxygen and mass transfer coefficients . The present findings can be applied to bioreactor desing for waste water treatment. Water Sci Technol, 2001, 44(7), 51 - 6 Watershed monitoring to address contamination source issues and remediation of the contaminant impairments; Barnes PL et al.; The Big Blue River Basin is located in southeastern Nebraska and northeastern Kansas and consists of surface water in the Big Blue River, Little Blue River, Black Vermillion River, and various tributaries draining 24,968 km2 . Approximately 75% of the land area in the basin are cultivated cropland . The Big Blue River flows into Tuttle Creek Reservoir near Manhattan, Kansas . Releases from the lake are used to maintain streamflow in the Kansas River during low flow periods, contributing 27% of the mean flow rate of the Kansas River at its confluence with the Missouri River . Tuttle Creek Reservoir and the Kansas River are used as sources of public drinking water and meet many of the municipal drinking water supply needs of the urban population in Kansas from Junction City to Kansas City . Elevated concentrations of pesticides in the Big Blue River Basin are of growing concern in Kansas and Nebraska as concentrations may be exceeding public drinking water standards and water quality criteria for the protection of aquatic life . Pesticides cause significant problems for municipal water treatment plants in Kansas, as they are not appreciably removed during conventional water treatment processes unless activated carbon filtering is used . Pesticides have been detected during all months of the year with concentrations ranging up to 200 microg/l . If high concentration in water is associated with high flow conditions then large mass losses of pesticides can flow into the water supplies in this basin . This paper will investigate the use of a monitoring program to assess the non-point source of this atrazine contamination . Several practices will be examined that have shown ability to remediate or prevent these impairments. Rev Saude Publica, 2001 Oct, 35(5), 481 - 6 {Outbreak of hemolytic reactions associated with chlorine and chloramine residuals in hemodialysis water}; Calderaro RV et al.; OBJECTIVE: To investigate the process of water contamination and to assess the subsequent outbreak in the hemodialysis center . METHODS: In September 2000, sixteen patients undergoing chronic hemodialysis at a dialysis center in Minas Gerais, Brazil, experienced hemolytic reactions compatible with toxic symptoms due to chlorine and chloramine water contamination . Chlorine and chloramine concentrations in samples obtained from various sites of the dialysis center's water treatment and distribution system were measured . Case-patients were identified by reviewing medical records and nursing notes for all dialysis sessions carried out during the study period . Interviews with technicians, nursing and medical staff members were conducted . RESULTS: Reaction rate was significantly higher (p<0.028) during the outbreak period (September 25 to 27, 2000) than the pre-outbreak period (September 18 to 20, 2000) . All patients with toxic symptoms had been under dialysis with water treated by reverse osmosis equipment and had used dialysers manually reprocessed . Chlorine and chloramine residuals concentrations found in the dialysis water as well as in the dialysers were at levels higher than regulations, </=0.5 mg/L for chlorine and </= 0.1 mg/L for chloramine . Individuals exposed to high chlorine and chloramine concentrations presented a relative risk of 2.58 (1.0-6.28) of having hemolytic reactions . CONCLUSION: There is a need to observe surveillance procedures to secure that the maximum allowable concentrations of regulated substances in the water used in the hemodialysis process are not exceeded. Environ Sci Technol, 2001 Nov 1, 35(21), 4252 - 9 MTBE oxidation by conventional ozonation and the combination ozone/hydrogen peroxide: efficiency of the processes and bromate formation; Acero JL et al.; The present study investigates the oxidation of methyl tert-butyl ether (MTBE) by conventional ozonation and the advanced oxidation process (AOP) ozone/hydrogen peroxide under drinking water treatment conditions . The major degradation products identified were tert-butyl formate (TBF), tert-butyl alcohol (TBA), 2-methoxy-2-methyl propionaldehyde (MMP), acetone (AC), methyl acetate (MA), hydroxyisobutyraldehyde (HiBA), and formaldehyde (FA) . The rate constants of the reaction of ozone and OH radicals with MTBE were found to be 0.14 and 1.9 x 10(9) M(-1) s(-1), respectively . The rate constants for the same oxidation processes were also measured for the degradation products TBF, MMP, MA, and HiBA (k(O3-TBF) = 0.78 M(-1) s(-1); k(OH-TBF) = 7.0 x 10(8) M(-1) s(-1); k(O3-MMP) = 5 M(-1) s(-1); k(OH-MMP) = 3 x 10(9) M(-1) s(-1), k(O3-MA) = 0.09 M(-1) s(-1), k(O3-HiBA) = 5 M(-1) s(-1); k(OH-HiBA) = 3 x 10(9) M(-1) s(-1)) . Since all compounds reacted slowly with molecular ozone, only the degradation pathway of MTBE with OH radicals has been determined, including the formation of primary degradation products . In experiments performed with several natural waters, the efficiency of MTBE elimination and the formation of bromate as disinfection byproduct have been measured . With a bromide level of 50 microg/L, only 35-50% of MTBE could be eliminated by the AOP O3/H2O2 without exceeding the current drinking water standard of bromate (10 microg/L) . The transient concentrations of MTBE and its primary degradation products were modeled using a combination of kinetic parameters (degradation product distribution and rate constants) together with the ozone and OH radical concentration and were in good agreement with the experimental results. Ground Water, 2001 Nov-Dec, 39(6), 921 - 30 Characterization of iron and manganese precipitates from an in situ ground water treatment plant; Mettler S et al.; Aquifer samples from the precipitation zone of an in situ iron and manganese removal plant that was operated for 10 years were analyzed for iron and manganese minerals . Measurements were performed by various chemical extraction techniques (5 M HCI, 0.008 M Ti(III)-EDTA, 0.114 M ascorbic acid), X-ray diffraction and Mossbauer spectroscopy . Chemical extractions showed that iron was precipitated as ferric oxides, whereas manganese was not oxidized but deposited as Mn(II) probably within carbonates . The ferric oxides in particular accumulate preferentially in the smaller grain- size fractions . This tendency was observed to a lesser extent for manganese . X-ray diffraction and Mossbauer spectroscopy showed that the ferric oxides were mainly crystalline (goethite, 50% to 100% of the iron) . Ferrihydrite was found as well, but only as a minor fraction (< or = 12%) . Pure manganese minerals were not found by X-ray diffraction . The precipitated amounts of iron (5 to 27 micromol/g Fe as ferric oxide) and manganese (1 to 4 micromol/g Mn) during 10 years operation of the treatment plant agree with values that were estimated from operational parameters (9 to 31 micromol/g Fe and 3 to 6 micromol/g Mn) . Considering the small amounts of precipitated iron and manganese, no long-term risks of clogging of the aquifer are expected. Water Sci Technol, 2001, 44(6), 73 - 80 Sludge and washwater management strategies for the Vaalkop water treatment plant; Haarhoff J et al.; The Vaalkop plant, owned and operated by Magalies Water, provides a valuable South African case study of sludge and washwater management at a large water treatment plant . Starting out as a small plant of 18 Ml/day about thirty years ago, it has steadily grown to a plant with treatment capacity of 210 Ml/day; fairly large by South African standards . During the preceding years, it has not only been subject to a vastly larger scale of operation, but it also had to adapt to a tremendous increase in the cost of raw water, an increased environmental awareness amongst water treatment professionals and general public alike, and a much more sophisticated and complicated legislative framework . It is the objective of this paper to track the sludge and washwater management practices adopted over the years at Vaalkop, and to present the current strategies adopted for the medium to long term . The paper will summarize the previous methods of sludge and washwater disposal, with reasons why they were adopted . The multitude of technical analyses and alternatives that were performed over the years will be summarized, and may provide valuable pointers for other applications in South Africa . The current system, which has just been commissioned, will be presented; its technical design parameters, the anticipated mode of operation, its costs and how the current environmental and legislative requirements are being met. Biol Trace Elem Res, 2001 Summer, 82(1-3), 185 - 200 Zinc supplementation prevents liver injury in chlorpyrifos-treated rats; Goel A et al.; The present study was performed to investigate the protective effects of zinc (227 mg/L in drinking water) treatment in chlorpyrifos (13.5 mg/kg body weight, orally) induced hepatotoxicity in male rats . Animals received chlorpyrifos and/or zinc treatments for 8 wk . A 99mTc-mebrofenin clearance test was done to determine the biological half-life (Tbiol) of the radiopharmaceutical in liver for the determination of the hepatobiliary function of the animals . At the end of treatment periods, samples were collected for the measurement of zinc levels in serum and liver . Electron microscopic studies were performed to study hepatic ultrastructure following various treatments . When compared to normal controls, chlorpyrifos treatment resulted in reduced hepatic and serum zinc levels (p < 0.01) . The biological half-life (Tbiol) of 99mTc-mebrofenin in liver was increased (p < 0.01) significantly in chlorpyrifos-treated animals, reflecting a poor excretion of the radiopharmaceutical from the liver . Simultaneous zinc supplementation retained the increased hepatic Tbiol values of 99mTc-mebrofenin within normal limits . Zinc treatment also protected hepatocytes from the marked disruptions in the membranous organelles and narrowing/blocking of biliary channels, which was otherwise a common observation following chlorpyrifos treatment . These data clearly show the protective effects of zinc in animals subjected to organophosphate poisoning. Chemosphere, 2001 Nov, 45(6-7), 865 - 73 Molecular size distribution of natural organic matter in raw and drinking waters; Nissinen TK et al.; The purpose of this study was to compare the molecular size distribution (MSD) of natural organic matter (NOM) in raw waters (RW) and drinking waters (DW), and to find out the differences between MSD after different water treatment processes . The MSD of NOM of 34 RW and DW of Finnish waterworks were determined with high-performance size-exclusion chromatography (HPSEC) . Six distinct fractions were generally separated from water samples with the TSK G3000SW column, using sodium acetate at pH 7 as an eluent . Large and intermediate humic fractions were the most dominant fractions in surface waters (lakes and rivers), while in artificially recharged groundwaters and natural groundwaters intermediate and small fractions predominated . Water treatment processes removed the two largest fractions almost completely shifting the MSD towards smaller molecular size in DW . Granular activated carbon (GAC) filtration, ozonation, and their combination reduced all humic fractions compared to the conventional treatment . Humic fractions correlated with total organic carbon (TOC) content and chemical oxygen demand, this being especially true in RW . The results demonstrate that the HPSEC method can be applied for a qualitative and also for rough estimate quantitative analyzes of NOM directly from RW and DW samples without sample pretreatment. Water Sci Technol, 2001, 44(5), 263 - 70 Water treatment by TiO2 photocatalysis and/or ultrasound: degradations of phenyltrifluoromethylketone, a trifluoroacetic-acid-forming pollutant, and octan-1 -ol, a very hydrophobic pollutant; Theron P et al.; TiO2 photocatalysis and ultrasound are advanced oxidation processes for water treatment . Our study aimed at showing, via the purposely chosen title compounds, that these techniques can be complementary . For C6H5COCF3 (PTMK), the photocatalytic removal rate was higher than the ultrasonic (515 kHz) removal rate in the presence of TiO2 in the dark, whereas it was the opposite for octan-1-ol under the conditions employed . Simultaneous UV and ultrasound irradiation of the TiO2 suspension led, for PTMK, to a removal rate about equal to the sum of the removal rates observed for separate irradiations, and decreased by a factor of approximately 20% for octan- 1 -ol as if the photocatalytic degradation was suppressed by the dominant distribution of octan-1-ol to the cavitation bubbles . This distribution was substantiated by the large detrimental effect of octan- 1-ol on the PTMK ultrasonic removal rate . The concurrent use of both techniques allowed a faster removal of both pollutants in binary mixtures . The amount of CF3COOH from PTMK was approximately eight times lower in sonicated, than in UV-irradiated, TiO2 suspensions . Several intermediate products showed the occurrence of chemical transformations occurring in and/or on the cavitation bubbles . COD decline and CO2 formation were initially higher for ultrasonic than for photocatalytic treatment . However, complete mineralization (except for CF3COOH) was achieved more rapidly by photocatalysis and even more rapidly by simultaneous use of both techniques. J Nutr, 2001 Nov, 131(11), 2848 - 52 Oolong tea increases metabolic rate and fat oxidation in men; Rumpler W et al.; According to traditional Chinese belief, oolong tea is effective in the control of body weight . Few controlled studies, however, have been conducted to measure the impact of tea on energy expenditure (EE) of humans . A randomized cross-over design was used to compare 24-h EE of 12 men consuming each of four treatments: 1) water, 2) full-strength tea (daily allotment brewed from 15 g of tea), 3) half-strength tea (brewed from 7.5 g tea) and 4) water containing 270 mg caffeine, equivalent to the concentration in the full-strength tea treatment . Subjects refrained from consuming caffeine or flavonoids for 4 d prior to the study . Tea was brewed each morning; beverages were consumed at room temperature as five 300 mL servings . Subjects received each treatment for 3 d; on the third day, EE was measured by indirect calorimetry in a room calorimeter . For the 3 d, subjects consumed a typical American diet . Energy content of the diet was tailored to each subject's needs as determined from a preliminary measure of 24-h EE by calorimetry . Relative to the water treatment, EE was significantly increased 2.9 and 3.4% for the full-strength tea and caffeinated water treatments, respectively . This increase over water alone represented an additional expenditure of 281 and 331 kJ/d for subjects treated with full-strength tea and caffeinated water, respectively . In addition, fat oxidation was significantly higher (12%) when subjects consumed the full-strength tea rather than water. Epidemiol Infect, 2001 Oct, 127(2), 237 - 44 Microbiologic effectiveness of hand washing with soap in an urban squatter settlement, Karachi, Pakistan; Luby SP et al.; We conducted a study in a squatter settlement in Karachi, Pakistan where residents report commonly washing their hands to determine if providing soap, encouraging hand washing, and improving wash-water quality would improve hand cleanliness . We allocated interventions to 75 mothers and collected hand-rinse samples on unannounced visits . In the final model compared with mothers who received no hand-washing intervention, mothers who received soap would be expected to have 65% fewer thermotolerant coliform bacteria on their hands (95% CI 40%, 79%) and mothers who received soap, a safe water storage vessel, hypochlorite for water treatment, and instructions to wash their hands with soap and chlorinated water would be expected to have 74% fewer (95% CI 57%, 84%) . The difference between those who received soap alone, and those who received soap plus the safe water vessel was not significant (P = 0.26) . Providing soap and promoting hand washing measurably improved mothers' hand cleanliness even when used with contaminated water. FEMS Microbiol Lett, 2001 Oct 16, 204(1), 71 - 4 Evidence for additional genus-level diversity of Chlamydiales in the environment; Horn M et al.; The medically important order Chlamydiales has long been considered to contain a few closely related bacteria which occur exclusively in animals and humans . This perception of diversity and habitat had to be revised with the recent identification of the genera Simkania, Waddlia, Parachlamydia, and Neochlamydia with the latter two comprising endosymbionts of amoebae . Application of a newly developed PCR assay for the specific amplification of a near full length 16S rDNA fragment of these novel Chlamydia-related bacteria on activated sludge samples revealed the existence of at least four additional, previously unknown evolutionary lineages of Chlamydiales (each showing less than 92% 16S rRNA sequence similarity with all recognized members of this order) . These findings suggest that some waste water treatment plants represent reservoirs for a diverse assemblage of environmental chlamydiae, a discovery which might also be of relevance from the viewpoint of human public health. J Chromatogr A, 2001 Sep 28, 930(1-2), 9 - 19 Determination of phenylurea herbicides in natural waters at concentrations below 1 ng l(-1) using solid-phase extraction, derivatization, and solid-phase microextraction-gas chromatography-mass spectrometry; Gerecke AC et al.; A procedure is presented which allows the ultratrace level determination of phenylurea herbicides (PUHs) in natural waters . Samples were enriched by solid-phase extraction (SPE) on Carbopack B and alkylated with iodoethane and sodium hydride to yield thermostable products . After derivatization, the aqueous samples were extracted and injected by SPME . The use of iodoethane instead of iodomethane allowed the differentiation between parent compounds and the N-demethylated metabolites . Limits of detection were between 0.3 and 1.0 ng/l for the parent compounds . Standard deviations below 10% were achieved for samples containing more than 4 ng/l in very different matrices including Nanopure water, lake water, and waste water treatment plant (WWTP) effluent . Moreover, the para-hydroxylated metabolite of diuron could be quantified with the same procedure . The presence of further metabolites was assessed qualitatively . Chromatography was stable over a large number of measurements even with dirty samples from WWTP effluent . The precision and sensitivity of the developed analytical method allowed the investigation of the fate of PUHs in lakes, their degradation during drinking water treatment and their transport within the North Sea. Environ Toxicol, 2001 Oct, 16(5), 422 - 7 Testing the toxicity of influents to activated sludge plants with the Vibrio fischeri bioassay utilising a sludge matrix; Hoffmann C et al.; To protect the bioceonosis within activated sludge, a method of predicting the toxic effect of influents to the biological treatment stage of waste water treatment plants, based on DIN method 38412 L 34, has been developed . A population of the luminescent marine bacterium Vibrio fischeri was incorporated into a sludge testing matrix derived from a model laboratory and real activated sludge plants . The sludge was challenged with different concentrations of pure toxicants and complex aqueous samples, and light output by V . fischeri monitored . The results were compared to toxicant testing in the absence of sludge (standard test) . The modified method was found to be less sensitive for some toxicants tested than the standard DIN and other bioluminescent tests, but considered more realistic as it provides buffering and takes into account sorption which can affect the sensitivity of the test towards some compounds . The method is comparable in terms of ease of use, speed, reproducibility and cost effectiveness to standard V . fischeri luminescence methods. J Environ Manage, 2001 Sep, 63(1), 87 - 102 The effect of limited options and policy interactions on water storage policy in south Florida; Mayer AL; Due to environmental constraints and reactive water management practices, water shortages exist across the Everglades ecosystem . A growing human population and continued wetlands damage and loss decrease the system's ability to provide water for sustained natural areas and for human uses . 'The Restudy' is an $8 billion plan to restore the Everglades while also continuing to provide water storage for urban and agricultural areas . The Restudy proposes a mix of water storage systems to provide for the predicted future growth in water demand . This mix is purported to be the most cost-efficient at providing water supplies, within the constraints of unchanged agricultural and urban land use . However, a sensitivity analysis of the Restudy's cost equation reveals that the total cost of water storage systems is influenced by real estate, land acquisition and water treatment costs . The interaction of land use and agricultural policies can affect these cost factors, and can change the relative cost-efficiency between storage systems . Real estate and land acquisition costs are affected by several 1996 Farm Bill provisions, which influence the cost of aboveground water storage systems versus Aquifer Storage and Recovery systems . The Governor's Commission for a Sustainable South Florida recommendations also influence the water storage options available to the Restudy . Due to the Restudy's initial assumptions and constraints, it may not advocate the most economically and ecologically sound remediation. Nephrol Dial Transplant, 2001, 16 Suppl 7, 29 - 35 Dialysis: its role in optimizing recombinant erythropoietin treatment; Locatelli F et al.; Although iron deficiency is probably the most important factor affecting response to recombinant erythropoietin (Epo, epoetin), other factors are of significance, including dialysis adequacy . Additionally, water treatment and distribution, sterilizants and the quality of the dialysate in terms of trace elements (particularly chloramine) are of importance in relation to erythropoiesis inhibition . Microbiological or pyrogenic contamination can cause or aggravate anaemia in haemodialysis patients, and the impact of enhanced production of cytokines should be taken into consideration . By removing small and (possibly) medium/large molecules, adequate dialysis is of paramount importance in correcting anaemia and optimizing epoetin therapy . The biocompatibility of dialysis membranes and flux are other important factors . As yet unknown uraemic toxins may suppress erythropoiesis and contribute towards the development of anaemia . It is reasonable to hypothesize that, because anaemia improves after the start of dialysis with cellulose membranes, low molecular weight erythropoiesis inhibitors are involved, as well as medium/large molecular weight inhibitors, which are removed by more permeable membranes . However, in highly selected, adequately dialysed patients without iron or vitamin depletion, the effects of dialysis membrane type on haematological parameters and epoetin efficacy are smaller than might be expected from the results of uncontrolled studies . Improvement in anaemia has been observed using on-line haemofiltration, haemodiafiltration, and sterile dialysate . The results of prospective, randomized trials examining the impact of these factors on anaemia and the effectiveness of epoetin treatment are eagerly awaited. CNS Drugs, 2001, 15(9), 691 - 9 Dementia in patients undergoing long-term dialysis: aetiology, differential diagnoses, epidemiology and management; Rob PM et al.; Dementia in patients undergoing long-term dialysis has not been clearly defined; however, four different entities have been described . Uraemic encephalopathy is a complication of uraemia and responds well to dialysis . Dialysis encephalopathy syndrome, the result of acute intoxication of aluminium caused by the use of an aluminium-containing dialysate, was a common occurrence prior to 1980 . However, using modern techniques of water purification, such acute intoxication can now be avoided . Dialysis-associated encephalopathy/dementia (DAE) is always associated with elevated serum aluminium levels . Pathognomonic morphological changes in the brain have been described, but the mechanism for the entry of aluminium into the CNS is incompletely understood . The mechanisms involved in the pathogenesis of the neurotoxicity associated with aluminium are numerous . Although only a very small fraction of ingested aluminium is absorbed, the continuous oral aluminium intake from aluminium-based phosphate binders, and also of dietary or environmental origin, is responsible for aluminium overload in dialysis patients . Age-related dementia, especially vascular dementia, occurs in patients undergoing long-term dialysis as frequently as it does in the general population . The differential diagnoses of dialysis-associated dementias should include investigation for metabolic encephalopathies, heavy metal or trace element intoxications, and distinct structural neurological lesions such as subdural haematoma, normal pressure hydrocephalus, stroke and, particularly, hypertensive encephalopathy and multi-infarct dementia . To prevent DAE, dietary training programmes should aim to achieve the lowest phosphate intake and pharmacological tools should be used to keep serum phosphate levels below 2 mmol/L . To prevent vascular dementia, lifestyle modification should be undertaken, including optimal physical activity and fat intake, nicotine abstinence, and targeting optimal blood glucose, cholesterol and triglyceride levels, and blood pressure, to those outlined in current recommendations. Pediatr Clin North Am, 2001 Oct, 48(5), 1129 - 52, viii Is the water safe for my baby? Balbus JM, Lang ME. Children's behavior and physiology place them at unique risk from waterborne microbial and chemical contaminants . This article reveals children's susceptibility factors and the microbial and chemical contaminants of greatest importance to this age group . It also provides a primer on water treatment and alternatives to tap water . This article concludes with recommendations and resources to aid the practicing pediatrician in addressing patient concerns about drinking water. J Environ Qual, 2001 Sep-Oct, 30(5), 1693 - 8 Manure phosphorus extractability as affected by aluminum- and iron by-products and aerobic composting; Dao TH et al.; Shifts in manure phosphorus (P) chemical forms and pool sizes induced by water treatment residuals and industrial mineral by-products are largely undefined . We conducted a manure P fractionation study to determine mechanisms of reduction of dissolved reactive phosphorus (DRP) in poultry manure upon mineral by-product additions . The effects of composting on the P immobilization efficacy of the by-products were determined using laboratory self-heating composting simulators . The mineral by-products included an aluminum-water treatment residual (Al-WTR) and an iron-rich titanium-processing by-product . The noncomposted manure averaged 0.11 g g(-1) of total P as DRP forms . The by-products significantly reduced manure DRP, by an average of 39 and 48% in the Al- and the Fe-treated manure, respectively . The by-products also reduced the 0.5 M NH4F-extractable phosphorus (FEP) fraction . Shifts in P forms between FEP and 0.1 M NaOH-extractable phosphorus (SHEP) depended upon the Al and Fe contents of the by-products while the combined FEP + SHEP pool remained constant . Phosphate sorption measurements supported the observations that the Fe-rich by-product was more effective at reducing manure DRP and enhancing the formation of SHEP forms at the expense of FEP than the Al-WTR . Composting had no effect on the efficacy of either by-product to reduce DRP . Potential mechanisms of enhanced P stabilization in treated manure upon composting included chemical shifts from the DRP and FEP fractions to the citrate-bicarbonate-dithionite extractable P fraction . Thus, the choice of P immobilization agents affected the stability of immobilized P forms and should be taken into consideration in developing manure processing and nutrient stabilization methods. Can J Microbiol, 2001 Aug, 47(8), 782 - 6 Detection of Aeromonas hydrophila in a drinking-water distribution system: a field and pilot study; Chauret C et al.; A 16-month study was conducted on the presence of Aeromonas hydrophila in drinking water in Indiana, U.S.A . Enumeration was conducted in source water, in various sites within a water treatment plant, and in the distribution system in both bulk water and biofilm, as well as in a simulated (annular reactors) drinking-water distribution system . Presumptive Aeromonas spp . counts on source waters regularly approached 10(3)-10(4) CFU/100 mL, during summer months and granular activated carbon - filtered water counts ranged from <1 to 490 CFU/100 mL . In source water, presumptive Aeromonas levels were related to water temperature . Aeromonas hydrophila was never detected in the treatment plant effluent or distributed bulk water, showing disinfectant efficiency on suspended bacteria; however, isolates of A . hydrophila were identified in 7.7% of the biofilm samples, indicating a potential for regrowth and contamination of drinking-water distribution systems. Am J Public Health, 2001 Oct, 91(10), 1571 - 3 Challenges in implementing a point-of-use water quality intervention in rural Kenya; Makutsa P et al.; To prevent diarrheal diseases in western Kenya, CARE Kenya initiated the Water, Sanitation, and Education for Health (WASEH) Project in 1998 . The project targets 72 farming and fishing communities with a total population of 43 000 . Although the WASEH Project facilitated construction of shallow wells and pit latrines, the water quality still needed improvement . Consequently, in 2001, CARE implemented the Safe Water System (which consists of point-of-use water treatment with sodium hypochlorite, safe storage, and behavior change techniques) within the already established WASEH infrastructure, using existing community organizations in combination with a social marketing approach that introduced affordable products . The project has resulted in adoption rates of 33.5% for chemical water treatment and 18.5% for clay pots modified for safe water storage. Am J Public Health, 2001 Oct, 91(10), 1565 - 70 Not just a drop in the bucket: expanding access to point-of-use water treatment systems; Mintz E et al.; Since 1990, the number of people without access to safe water sources has remained constant at approximately 1.1 billion, of whom approximately 2.2 million die of waterborne disease each year . In developing countries, population growth and migrations strain existing water and sanitary infrastructure and complicate planning and construction of new infrastructure . Providing safe water for all is a long-term goal; however, relying only on time- and resource-intensive centralized solutions such as piped, treated water will leave hundreds of millions of people without safe water far into the future . Self-sustaining, decentralized approaches to making drinking water safe, including point-of-use chemical and solar disinfection, safe water storage, and behavioral change, have been widely field-tested . These options target the most affected, enhance health, contribute to development and productivity, and merit far greater priority for rapid implementation. Infect Dis Clin North Am, 2001 Sep, 15(3), 797 - 812, viii Infection control in hemodialysis units; Tokars JI et al.; Infectious complications of hemodialysis include bacterial infections caused by contaminated water or equipment, other bacterial infections (including vascular access infections), and bloodborne viruses (primarily the hepatitis B and C viruses) . Infections caused by contaminated water and equipment can be prevented by a well-designed water-treatment system, routine cleaning and disinfection of system components, and routine bacteriologic monitoring of dialysis water and dialysis fluid . Standard precautions with additional measures recommended specifically for dialysis centers will prevent transmission of bacteria and viruses from patient to patient . These precautions include routine use of gloves, handwashing, and cleaning and disinfection of the external surface of the dialysis machine and other environmental surfaces . In addition, preventing transmission of hepatitis B virus infection requires vaccination of susceptible patients and staff, avoiding dialyzer reuse, and use of a dedicated room, dialysis machine, and staff members when treating patients chronically infected with this virus. Huan Jing Ke Xue, 2001 Jul, 22(4), 95 - 9 {Super heavy oil produced water treatment by surface flow constructed wetland}; Ji G et al.; This paper adopts a new economic technology of treating super heavy oil produced water using surface flow reed wetland system . The field test was conducted at the average filtration rate of 3.33 cm/d . The average influent concentrations per year of COD, Oil, BOD5, TN were 459.16 mg/L, 27.65 mg/L, 33.52 mg/L, 13.74 mg/L, and the average effluent concentrations per year of above indices were 77.21 mg/L, 1.42 mg/L, 3.90 mg/L, 1.60 mg/L, respectively . Its respective removal ratios of COD, Oil, BOD5, TN and pH were 83.18%, 94.86%, 88.37%, 88.36%, 7.87-7.77 . Analyses showed that super heavy oil produced water had no obvious effect on soil and almost no effect on growth volume and quality of reeds . Results indicated that the surface flow reed wetland could provide an efficient economical, stable new means of treating super heavy oil produced water. Huan Jing Ke Xue, 2001 Jul, 22(4), 123 - 7 {Development of the heterogeneous photocatalytic reactor in water treatment}; He X et al.; Based on the history and the functions of the heterogenous photocatalytic reactors, three categories were discussed . The emphasis was put on the employment of the reactors designed for the practice in recent years . It was pointed out that the study and the design of the reactors were one of the cores in the process of the application of the photocatalytic oxidation techniques . And the trend of this technology was also predicted. Anal Biochem, 2001 Oct 1, 297(1), 94 - 8 Direct immunodetection of antigens within the precast polyacrylamide gel; Desai S et al.; Detection of specific proteins separated by SDS-PAGE is the basis for studying specific antigens . Immunodetection of antigens is commonly performed using Western blotting technique . In this paper we have shown that it is possible to eliminate Western blotting and to detect the antigens directly within the precast polyacrylamide gels by pretreating the gels with 50% isopropanol followed by distilled water treatment . This method would be valuable for large or difficult to transfer proteins . Environ Sci Technol, 2001 Sep 1, 35(17), 3526 - 34 Utilization of zeolites synthesized from coal fly ash for the purification of acid mine waters; Moreno N et al.; Two pilot plant products containing 65 and 45% NaP1 zeolite were obtained from two Spanish coal fly ashes (Narcea and Teruel Power Station, respectively) . The zeolitic product obtained showed a cation exchange capacity (CEC) of 2.7 and 2.0 mequiv/g, respectively . Decontamination tests of three acid mine waters from southwestern Spain were carried out using the zeolite derived from fly ash and commercial synthetic zeolite . The results demonstrate that the zeolitic material could be employed for heavy metal uptake in the water purification process . Doses of 5-30 g of zeolite/L have been applied according on the zeolite species and the heavy metal levels . Moreover, the application of zeolites increases the pH . This causes metal-bearing solid phases to precipitate and enhances the efficiency of the decontamination process. Environ Sci Technol, 2001 Sep 1, 35(17), 3476 - 81 Redox transformations of arsenic and iron in water treatment sludge during aging and TCLP extraction; Meng X et al.; Laboratory experiments and modeling studies were performed to investigate the redox transformations of arsenic and iron in water treatment sludge during aging, and to evaluate the impact of those transformations on the leachability of arsenic determined with the U.S . EPA toxicity characteristic leaching procedure (TCLP) . When the backwash suspension samples collected from a California surface water treatment plant were aged in closed containers for a few weeks, soluble arsenic increased from less than 5 microg/L to as high as 700 microg/L and then decreased dramatically because of biotic reduction of arsenate {As(V)}, ferric oxyhydroxide, and sulfate . The experimental results and the thermodynamic models showed that arsenic mobility can be divided into three redox zones: (a) an adsorption zone at pe > 0, which is characterized by strong adsorption of As(V) on ferric oxyhydroxide; (b) a mobilization (transition) zone at -4.0 < pe < 0, where arsenic is released because of reduction of ferric oxyhydroxide to ferrous iron and As(V) to arsenite {As(III)}; and (c) a reductive fixation zone at pe < -4.0, where arsenic is immobilized by pyrite and other reduced solid phases . The TCLP substantially underestimated the leachability of arsenic in the anoxic sludge collected from sludge ponds because of the oxidation of Fe(II) and As(III) by oxygen . The leaching test should be performed in zero-headspace vessels or under nitrogen to minimize the