Activated sludge

Anal Biochem, 1988 Nov 15, 175(1), 14 - 21
Clinical and biochemical applications of luciferases and luciferins; Kricka LJ; Recent advances in the analytical applications of bacterial and firefly luciferases and firefly luciferin are reviewed . Luciferases have been used in soluble and immobilized/co-immobilized forms in assays for a variety of enzymes, substrates, and cofactors . The firefly luciferase reaction forms the basis of rapid microbiological tests which have found application in susceptibility testing, detection of bacteriuria, activated sludge analysis, and food testing . Rapid microbiological assays are also possible using bacteriophages containing the lux genes from Virbrio harveyi . Both the firefly and the bacterial luciferase reaction have been applied in immunoassay and DNA probe assays and the firefly luciferin phosphate substrate for alkaline phosphatase labels has proven particularly successful.

Zentralbl Bakteriol Mikrobiol Hyg {A}, 1988 Aug, 269(2), 188 - 96
Characterization of Campylobacter jejuni and Campylobacter coli isolated from waste water; Stelzer W et al.; The raw sewage samples of the investigated municipal sewage plant (sewage flow of about 30,000 m3/d) contained about 10(3) campylobacters/100 ml . The sewage plant reduced 80.8% of organic wastes (COD), 85.0% of colony counts (20 degrees C), 92.5% of total coliforms and 88.0% of campylobacters . The sewage plant effluent contained an average of 1.3 X 10(2) campylobacters/100 ml . About 10(10) campylobacters are discharged with the effluent of the high-output sewage plant into the receiving water every day . No reduction of the indicator bacteria was found in the activated sludge tank, there was, however, a significant reduction (94.5%) of campylobacters . In total, 94 strains were differentiated by biotyping and serotyping . 59.6% were found to be Campylobacter jejuni and 40.4% were Campylobacter coli . 8 Serotypes were found among the C . jejuni strains and 12 among C . coli . The raw sewage of the investigated oxidation pond treatment plant contained an average of 51 campylobacters/100 ml . The sewage plant effluent did not show campylobacters in any case.

Appl Environ Microbiol, 1988 Jul, 54(7), 1880 - 1
Optimum pH levels for eluting enteroviruses from sludge solids with beef extract; Berg G et al.; This study demonstrates that elution of enteroviruses from a mixture of primary- and activated-sludge solids with beef extract at pH 9.2 +/- 0.2 may be less efficient than elution with beef extract at pH 7.2 +/- 0.2 and that elution of enteroviruses from extended-aeration-sludge solids with beef extract is at best no more efficient at pH 9.2 +/- 0.2 than at pH 7.2 +/- 0.2 . Thus, the common practice of adjusting the pH of beef extract used for eluting enteroviruses from the natural neutral level of the elutant to alkaline levels is unnecessary and probably undesirable.

Appl Environ Microbiol, 1988 Feb, 54(2), 294 - 301
Degradation of 1,2-dichlorobenzene by a Pseudomonas sp; Haigler BE et al.; A Pseudomonas sp . that was capable of growth on 1,2-dichlorobenzene (o-DCB) or chlorobenzene as a sole source of carbon and energy was isolated by selective enrichment from activated sludge . The initial steps involved in the degradation of o-DCB were investigated by isolation of metabolites, respirometry, and assay of enzymes in cell extracts . Extracts of o-DCB-grown cells converted radiolabeled o-DCB to 3,4-dichloro-cis-1,2-dihydroxycyclohexa-3,5-diene (o-DCB dihydrodiol) . 3,4-Dichlorocatechol and o-DCB dihydrodiol accumulated in culture fluids of cells exposed to o-DCB . The results suggest that o-DCB is initially converted by a dioxygenase to a dihydrodiol, which is converted to 3,4-dichlorocatechol by an NAD+-dependent dehydrogenase . Ring cleavage of 3,4-dichlorocatechol is by a catechol 1,2-oxygenase to form 2,3-dichloro-cis,cis-muconate . Preliminary results indicate that chloride is eliminated during subsequent lactonization of the 2,3-dichloro-cis,cis-muconate, followed by hydrolysis to form 5-chloromaleylacetic acid.

Schriftenr Ver Wasser Boden Lufthyg, 1988, 78, 267 - 76
Fate of genetically-engineered bacteria in activated sludge microcosms; Dwyer DF et al.; The conclusions that can be derived from this study regarding the fate of the GEMs and their ability to degrade added pollutants are as follows: 1 . Both GEMs were able to survive in the microcoms . Because Pseudomonas sp . B13 has been cultured for a long time in the laboratory, it was not expected to survive well in the microcosm . Surprisingly, it and the derivative GEMs persisted at a high population level of approximately 10(5) bacteria/ml . Pure culture studies had demonstrated an ability of FR1(pFRC20P) to readily degrade simultaneous mixtures of 3CB and 4MB . In the microcosms, however, the GEM did not perform as well as expected, particularly when confronted with a shock load of a 3CB and 4MB mixture . Thus, the microcosm studies may be of potential help for making predictions concerning environmental applications of GEMs . 2 . Pseudomonas sp . B13 derivative strains FR1 and FR1(pFRC20P) were able to degrade low concentrations of substituted benzoates within the complex ecosystem of the activated sludge microcosm . A good deal of information concerning the degradation pathway for aromatics by Pseudomonas sp . B13 was already known . This allowed for the construction of the stable, regulated pathways for the degradation of substituted aromatic compounds in both GEMs and indicates that the construction of similar GEMs for the degradation of environmental pollutants is a promising experimental strategy . 3 . There was not any demonstrable, adverse effect of GEM addition to the microbial population level in the microcosm . The GEMs were even able to function in a protective manner for the indigenous populations by buffering them against the adverse effects of addition of substituted benzoates . In contrast, for microcosms lacking GEM addition, a wash-out of the bacterial population in the microcosm occurred (data not shown) . 4 . Lateral transfer of new genetic information (xylXYZLS) from the GEM chromosome to indigenous microorganisms was not detected, whereas transfer of the hybrid, mobilizable pFRC20P carrying the gene for lactone isomerase did apparently occur . In this particular case, transfer may have been beneficial for the community as a whole if it increased the ecosystem's ability to cope with the presence of toxic pollutants . As more GEMs are constructed for specific biotechnological applications the diversity and complexity of microcosms used to study their fate and function will increase . The ability of such studies to predict a priori the fate of these microorganisms will help to develop strategies both to decrease the risks associated with introducing GEMs into the environment and to increase and regulate the capacity of GEMs to degrade toxic pollutants.(ABSTRACT TRUNCATED AT 400 WORDS)

Sci Total Environ, 1987 Oct, 66, 203 - 12
Management of wastewater from soap and food industries: a case study; el-Gohary FA et al.; This paper presents the wastewater management of an industrial complex which produces different products, i.e . soap, perfume extract, macaroni, jam and juices . A continuous monitoring programme for departmental as well as final effluents was carried out for almost 3 months . Characterization of the composite wastewater from both soap and food processing plants indicated that the waste was highly contaminated with organic compounds as indicated by COD and BOD values . Moreover, effluent from the soap manufacturing plant contains significant concentrations of oil and grease amounting to 563 mg l-1 . Soap manufacturing effluent and the combined wastes discharged from the whole industrial complex were subjected to different treatment processes, namely dissolved air flotation, chemical coagulation-sedimentation, and biological treatment via a completely mixed activated sludge process . Although coagulation using alum followed by sedimentation removed 52% of COD, residual values did not comply with the regulatory standards . Biological treatment of the composite combined wastewater significantly removed the organic contaminants in wastewater . Average residual BOD, COD, oil and grease values were 30, 92 and 8.3 mg l-1 respectively . Based on the laboratory results a final process design was developed.

Appl Environ Microbiol, 1987 Oct, 53(10), 2440 - 4
Measurement of the effects of cadmium stress on protozoan grazing of bacteria (bacterivory) in activated sludge by fluorescence microscopy; Hoffman RL et al.; The effect of cadmium stress on protozoan bacterivory in sewage sludge was measured by experimentally exposing sludge communities to 0 to 150 mg of Cd per liter for up to 6 h and then determining the rates of protozoan grazing on bacteria, using a double-staining technique and epifluorescence microscopy . Bacterivory was measured by incubating the sludge with fluorescently labeled bacterium-sized latex beads and directly observing ingestion of the beads and bacterial cells in the sludge by epifluorescence microscopy of preserved samples . Staining with 4',6-diamidino-2-phenylindole and acridine orange permitted the simultaneous determination of protozoan numbers and bacterivory activity as estimated by the number of bacterial cells and bacterium-sized latex beads ingested by the representative ciliate Aspidisca costata . Enumeration with latex beads proved to be an effective way of estimating bacterivory in sludges subjected to heavy-metal stress . This technique should prove useful for determining the effects of other chemical stresses on protozoan numbers and bacterivory in organic-rich environments . Although the number of protozoa declined significantly only after exposure to 100 mg of Cd per liter for 4 h, grazing, as indicated by bead ingestion, was significantly inhibited by Cd concentrations of greater than 25 mg/liter in less than 1 h, and exposure to 100 mg of Cd per liter effectively stopped protozoan grazing within 1 h of exposure . Protozoan ingestion of latex beads and bacteria was inversely correlated to Cd concentration and exposure time . The reduction of protozoan bacterivory by Cd provides a possible explanation for the increase in suspended bacteria in the effluents of metal-stressed treatment facilities.

Biomed Environ Mass Spectrom, 1987 Jul, 14(7), 343 - 54
Thermospray LC/MS/MS analysis of wastewater for disperse azo dyes; Betowski LD et al.; Primary effluent from a municipal wastewater treatment plant was used as the feed in bench scale activated sludge systems . These systems were spiked with disperse azo dyes at 1 mg 1-1 and 5 mg 1-1 levels and were sampled at various points in the process . Samples were analysed by high performance liquid chromatography with UV = visible detection and by thermospray ionization MS and tandem mass spectrometry (MS/MS) using direct injection or via column chromatography . The tandem mass spectrometry techniques were used both for method development purposes and for the specificity and extra information these techniques can provide . The investigation of the fate of disperse azo dyes in the activated sludge process was a major feature of this study . Major degradation products have been identified by tandem mass spectrometry analyses of these wastewaters . Precision and accuracy data generated by the thermospray tandem mass spectrometry technique are compared to those derived from the high performance liquid chromatography/UV-visible method.

Zentralbl Bakteriol Mikrobiol Hyg {B}, 1987 Jun, 184(3-4), 195 - 205
{Quantitative studies of the elimination of Salmonellae by biological wastewater treatment}; Kayser R et al.; The wastewater pretreatment plant of Braunschweig works as a conventional, one step activated sludge plant without primary settling tanks . There were about 37,000 m3 per day of effluent during our investigations . During some months daily quantitative determinations of salmonellae were performed in the raw wastewater, in the activated sludge, and in the effluent . The mean concentrations of salmonellae were in the raw wastewater 2 X 10(5)/l and in the effluent after 11h of aeration and then settling 2 X 10(4) cells/l . The concentrations of salmonellae varied about the factor 10(3) (limits 10(2) to 10(5)) . A small peak in the spring, a big peak in the late summer, and a week pattern were observed . The most salmonellae were adsorbed to unsoluble flocs of sludge, about 30-35% of the salmonellae only were found freely in the water and from that about 60% were concentrated round the flocs . Therefore, one step of settling removes about 90% of all salmonellae . In generally terms, the settling seems to be the most important step of removal of salmonellae from wastewater . Furthermore, the rate of removal is depending of the concentration . High concentrations of salmonellae cause a strong reduction and conversely . An immediate removal of salmonellae was observed in about 60%, however, there was a propagation of salmonellae in 30% of all samples, especially under conditions of low aeration, in an anaerobic environment, respectively.

Appl Environ Microbiol, 1987 May, 53(5), 1010 - 9
Degradation of 1,4-dichlorobenzene by a Pseudomonas sp; Spain JC et al.; A Pseudomonas species able to degrade p-dichlorobenzene as the sole source of carbon and energy was isolated by selective enrichment from activated sludge . The organism also grew well on chlorobenzene and benzene . Washed cells released chloride in stoichiometric amounts from o-, m-, and p-dichlorobenzene, 2,5-dichlorophenol, 4-chlorophenol, 3-chlorocatechol, 4-chlorocatechol, and 3,6-dichlorocatechol . Initial steps in the pathway for p-dichlorobenzene degradation were determined by isolation of metabolites, simultaneous adaptation studies, and assay of enzymes in cell extracts . Results indicate that p-dichlorobenzene was initially converted by a dioxygenase to 3,6-dichloro-cis-1,2-dihydroxycyclohexa-3,5-diene, which was converted to 3,6-dichlorocatechol by an NAD+-dependent dehydrogenase . Ring cleavage of 3,6-dichlorocatechol was by a 1,2-oxygenase to form 2,5-dichloro-cis, cis-muconate . Enzymes for degradation of haloaromatic compounds were induced in cells grown on chlorobenzene or p-dichlorobenzene, but not in cells grown on benzene, succinate, or yeast extract . Enzymes of the ortho pathway induced in cells grown on benzene did not attack chlorobenzenes or chlorocatechols.

Appl Environ Microbiol, 1987 Apr, 53(4), 621 - 6
Characterization of virucidal agents in activated sludge; Knowlton DR et al.; A comprehensive study was carried out to determine the properties of agents responsible for loss of virus infectivity in mixed-liquor suspended solids (MLSS) of activated sludge . Initial experiments revealed that model enteric viruses (poliovirus-1 and rotavirus SA-11) were irreversibly inactivated in MLSS and released their RNA genomes . Enteric viruses belonging to other genera (echovirus-12, coxsackievirus A13, reovirus-3) were also shown to lose infectivity in MLSS . Although the virucidal activity decreased at reduced temperatures, MLSS still retained significant activity at 4 degrees C . The virucidal agents in MLSS were stable for months at 4 degrees C, but their activity decreased approximately 50% during 4 days of aeration at 26 degrees C . Primary effluent, the nutrient source for activated sludge, also contained virucidal activity . After centrifugation of MLSS, almost all virucidal activity was found in the particulate fraction because of inhibitory substances retained in the supernatant fraction . Decreasing or increasing the solids concentration of the particulate fraction did not increase the virucidal activity of the fraction . The effects of heat and antibiotics on the virucidal activity of MLSS, coupled with the finding that the activity can be produced in autoclaved primary effluent seeded with MLSS, strongly support the conclusion that microorganisms are responsible for this activity . Attempts to characterize the virucidal microbial components of MLSS indicated that treatments that resulted in the inactivation or removal of microorganisms also caused a loss of virucidal activity . Thus, it appears that the virucidal components of microorganisms are either short-lived or active only while bound to the organisms themselves.

Appl Environ Microbiol, 1987 Mar, 53(3), 561 - 6
Degradation of n-haloalkanes and alpha, omega-dihaloalkanes by wild-type and mutants of Acinetobacter sp . strain GJ70; Janssen DB et al.; A 1,6-dichlorohexane-degrading strain of Acinetobacter sp . was isolated from activated sludge . The organism could grow with and quantitatively release halide from 1,6-dichlorohexane, 1,9-dichlorononane, 1-chloropentane, 1-chlorobutane, 1-bromopentane, ethylbromide, and 1-iodopropane . Crude extracts contained an inducible novel dehalogenase that liberated halide from the above compounds and also from 1,3-dichloropropane, 1,2-dibromoethane, and 2-bromoethanol . The latter two compounds were toxic suicide substrates for the organism at concentrations of 10 and 5 microM, respectively . Mutants resistant to 1,2-dibromoethane (3 mM) lacked dehalogenase activity and did not utilize haloalkanes for growth . Mutants resistant to both 1,2-dibromoethane (3 mM) and 2-bromoethanol (30 mM) could no longer oxidize or utilize alcohols and were capable of hydrolytic dehalogenation of 1,2-dibromoethane to ethylene glycol.

Acta Biol Hung, 1987, 38(1), 107 - 26
The effect of organic loadings on the performance of rotating biological contactors; Ewida KT; It has become a mere fact that the ever expanding growth of the population and the development of technology in our societies are causing damaging pollution problems in our natural waters . Biological treatment processes have become a major technology for wastewater treatment whether municipal or industrial . The Rotating Biological Contactors (RBC's) Process is a relatively new biological wastewater treatment process compared to other biological treatment processes, such as activated sludge and trickling filters . Although the biological mechanisms for wastewater treatment for RBC's and activated sludge are the same, there are some differences relative to fixed bed growth versus fluidized bed growth systems . The performance of RBC's is affected by a number of design parameters such as flow rate, rotational speed, detention time, temperature of wastewater, disc surface area, submerged disc depth, and organic loading . The work presented here gives a description, analysis and discussion of the effect of organic loading which is a paramount parameter of the performance of RBC's . The study shows the tremendous effect of organic loading on the performance of RBC's, through experimental as well as analytical techniques . It also correlates the performance at each stage of the process to the organic loading which is a major design factor for the manufacturing system of RBC's.

Microbios, 1987, 52(210), 7 - 16
Enumeration of pathogenic bacteria from sewage sludge in Kuwait; Sallal AK; Domestic sewage in Kuwait is mainly treated by an activated sludge process . Sewage sludges at different treatment stages and the digested sludge were studied for their content of pathogenic bacteria . Two Gram-positive cocci and eight Gram-negative bacilli were isolated and enumerated in the sewage sludges and in raw sewage . During March, Aeromonas hydrophila was the dominant bacterium isolated . Serratia liquefaciens in raw sewage and sludge-2, and Salmonella species in digested sludge were dominant during April . Enterobacter aerogenes was dominant in sewage samples in May . Various types of bacteria isolated were tested for their sensitivity to a wide range of antibiotics.

Acta Microbiol Pol, 1987, 36(3), 259 - 65
Studies on the resistance of activated sludge bacteria to high concentrations of methanol, butanol, glycol, cyclohexanone and cyclohexylamine; Bieszkiewicz E et al.; The resistance of bacterial strains isolated from activated sludge purifying petrochemical wastewaters to high concentrations of methanol, butanol, glycol, cyclohexanone and cyclohexylamine was examined . The strains were found to be resistant to up to 5000 mg/l of methanol, butanol and glycol . Cyclohexylamine in concentration 1500 mg/l completely inhibited the growth of all examined strains whereas cyclohexanone even at concentration 4500 mg/l eliminated only about half of the isolated strains . The highest resistance to cyclohexane derivatives was shown by bacteria belonging to Pseudomonas III . None of the studied strains was, however, able to utilize cyclohexanone and cyclohexylamine as a source of barbon and energy.

Acta Microbiol Pol, 1987, 36(1-2), 143 - 9
Effect of phenolic tar on the work of activated sludge; Bieszkiewicz E et al.; The effect of different phenolic tar concentrations on the work of activated sludge in petrochemical and synthetic wastewater was investigated . The concentrations of 440 and 300 mg/l of phenolic tar did not show a destructive effect on the activated sludge and its work . The highest concentration of phenolic tar (880 mg/l) reduced the efficiency of purification and changed the structure of the activated sludge.

Acta Microbiol Pol, 1987, 36(1-2), 135 - 42
Bacteriological studies of excess activated sludge subjected to aerobic mineralization; Lopatowska K; Quantitative and qualitative changes in the composition of bacterial microflora occur in the course of mineralization of excess activated sludge formed during the purification of crude oil refining wastewaters were studied . The excess activated sludge was dominated by Gram-negative bacteria belonging to the genera Pseudomonas III and IV . Mineralization of the excess sludge in both stationary and semicontinuous systems was accompanied by quantitative changes in the composition of the individual groups of Gram-negative bacteria . The frequency of Pseudomonas was reduced in favour of the Enterobacteriaceae, Achromobacter and Alcaligenes.

Sci Total Environ, 1986 Dec 1, 57, 161 - 70
Ultimate biodegradation of 2-, 3- and 4-nitrotoluene; Struijs J et al.; The biodegradation of 2-, 3- and 4-nitrotoluene was investigated in a simple laboratory test . All three isomers are shown to be biodegradable in a die-away test after adaptation of the inoculum, though different results were obtained with different types of activated sludges used as inoculum in the static test . The adaptation procedure, employed in this study, was a modification of a test method described by Pitter in 1976 . It appeared that adaptation in a semi-continuous activated sludge system was most successful when a composite sludge was used consisting of activated sludge from a communal sewage plant and an extract of river mud . meta-Nitrotoluene was more resistant to attack by a mixed population of aquatic micro-organisms than the other isomers . The procedure used in this study is proposed as an attractive alternative for those methods which are recommended by the OECD and the EEC, to test the so-called 'inherent biodegradability'.

Ecotoxicol Environ Saf, 1986 Dec, 12(3), 206 - 12
Evaluation of the test method "activated sludge, respiration inhibition test" proposed by the OECD; Yoshioka Y et al.; The test method of "activated sludge, respiration inhibition test" proposed by the OECD was critically carried out and compared with other test methods . Investigation of test conditions showed that the moderate deviation from the test conditions defined by the OECD Test Guidelines did not have much effect on the result, and some modifications were proposed to improve the method . This method had a poor detection limit compared with the LC50 test with Oryzias latipes and EC50 of the growth inhibition test with Tetrahymena pyriformis . The susceptivity of the method was particularly poor for the chemicals which were highly toxic in the other two tests.

Ann Inst Pasteur Microbiol, 1986 Sep-Oct, 137B(2), 219 - 26
{Growth of lignocellulolytic microorganisms on activated sludge: potential application}; Godden B et al.; A culture medium containing activated sludge and sawdust supports the growth of numerous lignocellulolytic microorganisms . One of them, Phanerochaete chrysosporium could be used in a composite feed for ruminants.

Zentralbl Bakteriol Mikrobiol Hyg {B}, 1986 Apr, 182(2), 143 - 54
{Various Salmonella serotypes isolated at a sewage purification plant in a large city over a one-year period}; Sobotta B et al.; The paper offers the results of a one-year-survey of Salmonella-serotypes in a municipal sewage-purification plant with a capacity of roughly 70,000 m3 per day . Findings of a quantitative study had shown Salmonella-maxima in the activated-sludge-basin . This suggested specialized Salmonella-serotypes, resident in this part of the plant as a possible explanation which was to be verified by this study . On ten days samples were taken from the inlet, and the outlet of the primary-sedimentation-tank, the outlet of the activated-sludge-basin and the effluent of the final sedimentation-basin . A combination of membrane-filtration and MPN-Method with a fifefold enrichment in 2.5% tetrathionate was applied for salmonella isolation . Plating was done on malachit-green-chinablue-lactose-agar followed by serological typing . 1,587 strains representing 38 different serotypes (Table 1) were identified with S . typhi-murium (Fig . 1) accounting for 36% of the isolations followed by S . bovis-morbificans, S . hadar (Fig . 2) and S . panama . None of the serotypes found showed a preference of a special sampling point . The qualitative and quantitative distribution of Salmonella in the plant seems to depend on the Salmonella contents of the entering waste water mainly . The greatest variety of Salmonella-serotypes was located in the activated-sludge-basin (Table 2) where oxygen-enrichment seems to result in the best ecological conditions for Salmonella survival . 3.3% of 722 strains examined did not produce hydrogen-sulphide (Table 3) and some showed damaged flagella-antigens . As a possible explanation toxic influences in the sewage are discussed . The epidemiological links between findings of Salmonella in sewage and in man of the same area are established and results differing in some aspects explained by the high rate of unknown infections . The existence of an autochthonous Salmonella-population in the sewage plant could not be proved.

Zentralbl Bakteriol Mikrobiol Hyg {B}, 1986 Apr, 182(2), 131 - 42
{Various Salmonella serotypes isolated at a sewage purification plant in a smaller city over a one-year period}; Schusseler G et al.; A one-year-study was carried out in the waste-water treatment plant of Plon (population equivalents 60,000), which has a mechanical and a biological purification and an additional chemical flocculation . Samples were taken at five different places in the plant and examined for Salmonella by use of membrane-filtration and MPN-method . 2,611 Salmonella-strains, representing 23 species, were isolated and serologically typed from samples taken at ten days . S . typhi-murium was found most frequently (Table 1, Fig . 1) . The largest spectrum of different types was located in the activated sludge-basin and at the outlet of the chemical flocculation (Table 2) . No correlation could be established between the qualitative findings and the Salmonella-counts or other parameter like temperatures . All the ten species that have been officially reported to cause salmonellosis in man were also isolated from the sewage (Table 5) . Findings of other Salmonella-serotypes are attributed to unreported human infections and animals or other sources.

Microbiol Sci, 1986 Mar, 3(3), 92 - 5
Microbial degradation of phthalate esters; Kurane R; Nocardia erythropolis rapidly degrades phthalate esters . Phthalate esters were efficiently removed from wastewater by inoculating cells of N . erythropolis into activated sludge . A fluorescent antibody technique was successfully applied for tracing the specified microorganism in a mixed culture system . The metabolic pathway was investigated and enzymes were purified.

J Toxicol Environ Health, 1986, 18(2), 315 - 9
Cadmium in tissues of Japanese quail fed oat grain grown on municipal sludge-amended soil; Bache CA et al.; Oats were cultured on soil amended with municipal sewage sludge from Syracuse, N.Y., or on soil alone (control) . The oats were fed to male and female Japanese quail through four generations . The extent of absorption of cadmium by the oats and its deposition in tissues and eggs of the first and fourth generations of birds were determined . The tissue levels of cadmium found in the first (F0) generation were kidney greater than liver greater than muscle approximately equal to eggs, with the quail from the sludge-treatment group consistently showing the higher respective tissue levels . Female birds showed consistently higher tissue levels than those of the corresponding males . Kidney and liver tissues and eggs from the fourth generation (F3) quail fed the sludge-treatment diets were also higher than the corresponding controls, but tissues of the male quail were most often higher than the corresponding females.

Microbios, 1986, 46(188-189), 205 - 10
Nitrate-reducing bacteria in Kuwait domestic sewage; Sallal AK et al.; Domestic sewage in Kuwait is mainly treated by an activated-sludge process, where different effluents and sludges are separated . Nitrate reduction in the raw sewage, effluent-1 and effluent-2 were studied . Various enrichments of these sewage samples were effected using 0.2 mg/ml of nitrogen as potassium nitrate and/or 0.5% carbon as glucose . Addition of 0.2 mg/ml nitrate-nitrogen enhanced more ammonia production (117.6 micrograms/ml) in comparison with other enrichments to sewage samples . Nitrate-reducing bacteria were also at a maximum with nitrate enriched sewage samples, especially with effluent-1 (109 X 10(6)/ml) . Escherichia coli and Klebsiella pneumoniae were the only two nitrate-reducing bacteria found in all sewage samples tested . Nitrite was unstable during the 7 days incubation period under anaerobic conditions which suggests that nitrates are reduced to ammonia.

Ecotoxicol Environ Saf, 1985 Dec, 10(3), 290 - 4
The fate of soluble, recalcitrant, and adsorbing compounds in activated sludge plants . II; Wierich P; An inhomogeneous first-order differential equation allows description of the time-dependent concentration change of an adsorbing compound in an activated sludge plant . Besides those parameters formerly considered, i.e., adsorption constant and surplus sludge wastage rate, the difference in dry matter content of the wasted sludge and that remaining in the activated sludge stage are now taken into account as well . This facilitates a more exact calculation of the elimination . The essential advantage of the new model lies in its simpler and faster applicability . The equations are steady and can be integrated facilitating, e.g., the calculation of the mean retention time of the absorbed material in the activated sludge stage . Other mechanisms such as biodegradation, precipitation, flocculation, and stripping are, as in our older model, not taken into account.

Zentralbl Bakteriol Mikrobiol Hyg {B}, 1985 May, 180(5-6), 534 - 9
Preliminary evaluation of the ELISA as a tool for the detection of rotaviruses in activated sewage sludge; Agbalika F et al.; Samples of activated sludge were taken in three different treatment plants near Nancy (France) and in West Berlin (F.R.G.), and were investigated for their content of rotaviruses . After elution with beef extract (0.25%, pH 7.3) and ultrasonication, the samples were concentrated by protamine flocculation and, in a few cases, in parallel by ultracentrifugation . A commercially available ELISA test kit (Rotazyme, Abbott Diagnostics) was routinely used for rotavirus detection . Although both the Rotazyme and a laboratory-designed ELISA gave positive results for the suldge concentrates, confirmation with a blocking test and electron microscope (EM) was negative in all cases so far investigated . Therefore, the exclusive use of ELISA cannot be recommended for similar investigations as it may lead to false positive results . In this light, an additional verification step with neutralizing antibodies should be included by the ELISA kits' manufacturers to enable a quick confirmation of the user's results.

Appl Environ Microbiol, 1985 Apr, 49(4), 887 - 98
Filamentous sulfur bacteria of activated sludge: characterization of Thiothrix, Beggiatoa, and Eikelboom type 021N strains; Williams TM et al.; Seventeen strains of filamentous sulfur bacteria were isolated in axenic culture from activated sludge mixed liquor samples and sulfide-gradient enrichment cultures . Isolation procedures involved plating a concentrated inoculum of washed filaments onto media containing sulfide or thiosulfate . The isolates were identified as Thiothrix spp., Beggiatoa spp., and an organism of uncertain taxonomic status, designated type 021N . All bacteria were gram negative, reduced nitrate, and formed long, multicellular trichomes with internal reserves of sulfur, volutin, and sudanophilic material . Thiothrix spp . formed rosettes and gonidia, and four of six strains were ensheathed . Type 021N organisms utilized glucose, lacked a sheath, and differed from Thiothrix spp . in several aspects of cellular and cultural morphology . Beggiatoa spp . lacked catalase and oxidase, and filaments were motile . Biochemical and physiological characterization of the isolates revealed important distinguishing features between the three groups of bacteria . Strain differences were most evident among the Thiothrix cultures . A comparison of the filamentous sulfur bacteria with freshwater strains of Leucothrix was made also.

Antonie Van Leeuwenhoek, 1985, 51(1), 45 - 56
The degradation of 1-phenylalkanes by an oil-degrading strain of Acinetobacter lwoffi; Amund OO et al.; An oil-degrading bacterium identified as Acinetobacter lwoffi was isolated by elective culture on North Sea Forties crude oil from an activated sludge sample . It grew on a wide range of n-alkanes (C12-C28) and 1-phenylalkanes, including 1-phenyldodecane, 1-phenyltridecane and 1-phenyltetradecane . The organism degraded 1-phenyldodecane to phenylacetic acid which was further metabolized via homogentisic acid, whilst 1-phenyltridecane was transformed to trans-cinamic and 3-phenylpropionic acid which were not further metabolized . Evidence is presented for a relationship between aromatic amino acid catabolism and 1-phenyldodecane degradation in this organism.

Antonie Van Leeuwenhoek, 1985, 51(2), 179 - 92
Role of anaerobic spore-forming bacteria in the acidogenesis of glucose: changes induced by discontinuous or low-rate feed supply; Cohen A et al.; A mineral salts medium containing 1% (w/v) glucose providing carbon-limited growth conditions was subjected to anaerobic acidogenesis by mixed populations of bacteria in chemostat cultures . The formation of butyrate was shown to be dependent on the presence of saccharolytic anaerobic sporeformers in the acid-forming population . By the use of pasteurized activated sludge as an inoculum a culture was obtained consisting solely of anaerobic sporeformers that gave rise to the formation of butyrate, acetate, hydrogen and carbon dioxide as the main fermentation products . No formation of propionate could be detected . In this culture, the role of sporulation was investigated by applying periods of starvation and a single-step lowering of dilution rate (shift-down) . In an experiment using a mineral salts medium supplemented with 1% (w/v) glucose and 0.5% (w/v) casein hydrolysate formation of refractile forespores as well as cell lysis could be demonstrated after 6 h starvation . In mixed cultures, initially inoculated with non-pasteurized activated sludge, a regular interruption of feed supply for 1 h per day resulted in selection of non-sporulating anaerobes . The fermentation pattern changed to a production of propionate and acetate, with a concomitant reduction of gas production . Similar results were obtained with shift-down in dilution rate . A relative increase of propionate-forming bacteria was accomplished in a continuous culture experiment with regular two times 2-h periods of starvation per day . The propionate-forming microbial population consisted predominantly of curved rods, tentatively identified as Selenomonas sp.

Appl Environ Microbiol, 1985 Jan, 49(1), 33 - 6
Comparison of selective media for assay of coliphages in sewage effluent and lake water; Kennedy JE Jr et al.; Selective media, including EC medium, gram-negative broth, nutrient broth (with 0.05% sodium deoxycholate), and lactose broth (with 0.05% sodium deoxycholate), as well as nonselective nutrient and lactose broths, were compared for the enumeration of coliphages by the agar layer method from activated-sludge effluent and eutrophic-lake water from a lake receiving treated sewage effluent . Samples were plated directly or after chloroform treatment with Escherichia coli B, E . coli C, or a mixed host of both E . coli B and C . With the exception of gram-negative broth, direct assays of all samples with the selective media generally resulted in significantly higher (P less than 0.05) recoveries of coliphages than did assays of chloroform-treated samples with nutrient broth medium regardless of the host used . In addition, chloroform pretreatment resulted in decreased recovery of coliphages with each selective medium in most analyses . The highest recoveries of coliphages from all samples with each host, except lake water with E . coli C, were obtained by direct assay on EC medium . The selectivity of the EC and gram-negative media resulted in suppression of bacterial interference on direct assay plates comparable to that observed in nutrient agar medium with chloroform-treated samples . The use of certain selective media for the direct assay of environmental materials for coliphage may enhance the recovery of coliphages and obviate bacterial decontamination procedures.

J Hyg (Lond), 1984 Dec, 93(3), 639 - 43
The detection of rotaviruses in products of wastewater treatment; Bates J et al.; Rotaviruses present in products of wastewater treatment were assayed in MA104 cells by indirect immunofluorescence . Levels in settled sewage, activated sludge and effluent were greater than 10(3) per litre in March and April but virus was not detected during later months . This pattern correlated with the decline in laboratory reports of human rotavirus infection.

Prikl Biokhim Mikrobiol, 1984 Nov-Dec, 20(6), 831 - 5
{Determination of the biochemical oxygen demand in nutrient media using microbial flow-through electrodes}; Kulis IuIu et al.; Biochemical oxygen demand (BOD) in some culture media was determined by means of flow-through microbial electrodes, based on Hansenula anomala, Escherichia coli K-12, and activated sludge obtained from the All-Union Scientific-Research Institute of Applied Enzymology (Vilnius) . The sensitivity of the electrodes was 112.1, 65.5 and 32.8% O2, respectively, in the presence of 1 mM glucose as substrate . A maximum sensitivity of the electrodes, based on E . coli and activated sludge, was observed on pyruvate oxidation--120 and 82.3% O2 in the presence of 1 mM pyruvate . The yeast electrode exhibited a minimum sensitivity for sucrose--9.3% O2/mM . The time of the electrode response varies from 8 to 35 min, depending on the substrate used . BOD depends on pH of the solution . The microbial electrodes retained the initial sensitivity for 33--38 days . The were used for estimation of BOD in the Rider's and Shopfer's media.

Arch Tierernahr, 1984 Oct, 34(10), 731 - 7
{Transport of benzo(a)pyrene into animal organs following the feeding of activated sludge from swine manure}; Fiebig HJ et al.; In feeding experiments with pigs and fish (carp and trout) the test animals received quotas of activated sludge of 7.5 and 15% DM (pigs) and 20% (carp) in their mixed feed . In an experiment with trout in an aquarium the quota of activated sludge was increased from 20% to 50% . The benzo(a)pyrene content was ascertained in selected organs of the pigs (kidney, liver, bacon, muscles) and the edible parts of the fish . As a result of this experiment one can say that the feeding of activated sludge from pig manure does not result in an increased benzo(a)pyrene content in the tested organs of the pigs and the edible parts of the fish.

J Gen Microbiol, 1984 Aug, 130 ( Pt 8), 2035 - 42
Microthrix parvicella, a filamentous bacterium from activated sludge: growth on Tween 80 as carbon and energy source; Slijkhuis H et al.; Microthrix parvicella, cultivated in a medium with Tween 80 and Casamino acids, utilized only the oleic acid moiety of Tween 80 as carbon and energy source . The cell yield from Tween 80 was about 0.32 g dry weight of cells per g of Tween 80 consumed . As only the oleic acid moiety of Tween 80 was utilized, the cell yield from oleic acid was 1.3 g dry weight of cells per g oleic acid consumed . The amount of carbon produced as CO2 was less than 30% of the oleic acid-carbon and this low value was in agreement with the high cell yield . In batch culture M . parvicella stored large amounts of lipid material during the early growth phase . The fatty acids of the lipid globules were similar to the fatty acids supplied as carbon source . The percentage composition of the biomass changed to give C/N percentage ratios of about 15 during the early growth phase due to the high concentration of internal lipids and the low concentration of protein . The growth rate in batch culture was about 0.016 h-1 but was affected by the concentration of Casamino acids in the medium.

Zentralbl Bakteriol Mikrobiol Hyg {B}, 1984 Jun, 179(3), 259 - 65
{Occurrence of Pseudomonas aeruginosa in waste water and its behavior under biological treatment}; Geuenich HH et al.; 103 days long, the concentration of Pseudomonas aeruginosa was determined in 206 samples of raw wastewater and of the activated sludge after the biological step in the wastewater pretreatment plant of Braunschweig . 2594 strains of P . aeruginosa were isolated, 95.8% of them showed production of pyocyanin . The concentration of P . aeruginosa varied between 2.6 X 10(1) and 4.8 X 10(4) cells/ml . Neglecting some exceptions, there were about ten times more P . aeruginosa in the sludge than in the clearly filtered wastewater and about one hundred times more than in the clearly filtered effluent . In general, P . aeruginosa seem not to be reduced by the biological oxidation during the wastewater treatment . On the contrary, we observed a multiplication in 69% of all cases . The multiplication of P . aeruginosa during the biological oxidation is discussed . Finally, the hygienic role of sludge is discussed because P . aeruginosa are concentrated herein.

J Hyg (Lond), 1984 Feb, 92(1), 97 - 103
Reduction of naturally occurring enteroviruses by wastewater treatment processes; Morris R; The levels of cytopathic enteroviruses at two wastewater-treatment works were monitored over a period of 9 months . The maximum level of virus at works 1 was 72500 p.f.u . l-1 and at works 2, 57500 p.f.u . l-1 . Examination of process efficiency showed an overall reduction of 63% for works 1 and 26% for works 2 when used without lagooning . When lagooning was employed at the second works, virus reduction was 97% . Individual treatment processes showed poor reduction of virus levels . Sedimentation and rapid sand filtration had no significant effect on levels whilst both percolating filtration and activated sludge showed some reduction . Only lagooning resulted in substantial reductions of virus levels.

Rev Mal Respir, 1984, 1(2), 125 - 31
{Atmospheric and respiratory contamination by waste water aerosols}; Boutin P et al.; A study was undertaken of the particle size of aerosols, emitted by a treatment plant for urban waste water, by counting the total flora, using and Andersen apparatus . Evidence of significant bacterial contamination was obtained on the perimeter of the installations . Calculations were made on the data obtained using a method to show the number of viable particles deposited at different levels within the pulmonary tree . During the working day approximately 10(4) viable particles, representing 1.5 x 10(6) organisms, products of the common flora of activated sludge were inhaled . Only a small fraction enters the pulmonary acini; the greater part are swallowed or excreted via the nose or on coughing.

Acta Microbiol Pol, 1984, 33(2), 171 - 8
Enzymatic activity of activated sludge in biological treatment of wastewater containing dimethylamine, dimethylformamide and methylethylketone; Sztajer H et al.; Activated sludge treating synthetic wastewater carrying dimethylamine (DMA), dimethylformamide (DMF) and methylethylketone (MEK) was examined . The compounds in question were found to affect the enzymatic activity of the activated sludge . Dehydrogenase activity was higher than in control activated sludge and stabilization of this activity was achieved on the twelfth day of the run . Alkaline phosphatase activity was lower than in the control sludge . No correlation between activity of the studied enzymes and biodegradation of DMA, DMF and MEK was observed.

J Toxicol Environ Health, 1984, 14(2-3), 153 - 61
Toxicologic studies with male sheep grazing on municipal sludge-amended soil; Hogue DE et al.; Growing sheep were grazed for 152 d on grass-legume forage growing on soil that had been amended with municipal sewage sludge from Syracuse, N.Y., at 224 metric tons per hectare . Cadmium was higher, but not significantly (p greater than 0.05), in tissues of sheep fed the sludge-grown forage as compared to controls . No significant differences between the sludge or control treatments were found in weight of the complete or cauda epididymis or in percent progressive motility of cauda epididymal sperm . The sludge-treatment group had significantly larger testes (p less than 0.025) when expressed as a percentage of body weight, and higher blood uric acid values (p less than 0.05) . There were no observable changes in tissue ultrastructure of liver, kidney, muscle, or testes as examined by electron microscopy in either of the treatment groups . There were no significant differences for rate of animal weight gain, carcass weight, dressing percentage, or quality or yield grade of the carcases between the treatment groups.

Acta Microbiol Pol, 1984, 33(3-4), 271 - 6
Effect of benzene and xylene on the work of activated sludge; Bieszkiewicz E et al.; The effect of benzene and xylene on the work of activated sludge in synthetic wastewater was studied . The sludge was found to adapt with relative ease to increasing concentrations of benzene and xylene (up to 75 and 150 mg/l), respectively . Higher concentrations of both compounds were toxic for the sludge.

Acta Microbiol Pol, 1984, 33(3-4), 263 - 70
Removal of excess activated sludge by aerobic mineralization; Lopatowska K; The removal of excess activated sludge from biological purification plant treating crude oil refining wastewaters by the method of aerobic digestion was studied . In stationary system 58% of excess sludge was removed within 32 days . In semicontinvous system (with daily addition of sludge) 85--64% of the sludge was removed, depending on amount of excess activated sludge added . Enrichment of the aerating air in oxygen (10% v/v) increased the efficiency of sludge digestion by about 10%.

Appl Environ Microbiol, 1983 Oct, 46(4), 832 - 9
Microthrix parvicella, a filamentous bacterium isolated from activated sludge: cultivation in a chemically defined medium; Slijkhuis H; A large number of media have been tested for cultivating Microthris parvicella, a filamentous microorganism often present in the activated sludge of oxidation ditches . The bacterium was found to utilize oleic acid (preferably as Tween 80) as the sole source of carbon and energy . Sulfur is required in the reduced form . The tested media vary from a complex to a chemically defined medium . Growth yields of 1.3 to 1.5 g/liter were obtained on media containing Tween 80 (4 g/liter), reduced nitrogen and reduced sulfur compounds, calcium and magnesium salts, phosphate buffer, trace elements, thiamin, and cyanocobalamin . The optimum temperature for growing the organism is approximately 25 degrees C, and the pH of the nutrient medium should be above 7.

Zentralbl Bakteriol Mikrobiol Hyg {B}, 1983 Sep, 177(6), 482 - 9
{Comparative study on methods to recover indigenous viruses from samples of activated sewage sludge}; Wullenweber M et al.; Samples of activated sewage sludge were investigated for their contents of indigenous enteric viruses . Therefore sewage sludge solids were collected by centrifugation and the embedded viruses eluted by blending (Waring blendor), glycine buffer (0.05 M) treatment at pH 11.5 or Freon1 treatment . Eluted viruses were concentrated on microfiberglass filters ("Balston" filters) at pH 3.5 or by flocculation with beef extract (3%, pH 3.5) . Simple blending of the activated sludge was found being not very efficient, while the other two methods gave better results in freeing the viruses from the sewage flocs . Usually highest virus titers were obtained after glycine treatment and concentration with Balston filters . Freon treatment of activated sewage sludge produces aqueous supernatants containing much denaturated floc material which seems to cause a certain number of viruses to remain in the supernatant after flocculation.

Mikrobiologiia, 1983 Jan-Feb, 52(1), 149 - 55
{Activity of microorganisms in activated sludge in relation to the concentration of mercury in sewage}; Ilialetdinov AN et al.; Activated sludge from the refinery of a plant producing synthetic rubber was shown to adsorb mercury ions contained in the sewage . As a result, the content of microorganisms in the sludge as well as the activity of dehydrogenase decreased . The quantity of Pseudomonas aeruginosa cells was 40 x 10(6) per 1 ml in a chemically defined medium without mercury ions, 20 x 10(5) per 1 ml in the water after the first sedimentation tank (0.07 to 0.08 mg Hg per litre), and 10 x 10(6) per 1 ml in the water of sewage common to the whole plant (0.13 to 0.14 mg Hg per litre) . The use of the phage-resistant P-aeruginosa T-76 culture adapted to synthetic organic pollutants contained in the sewage of the plant together with the activated sludge of the refinery increased the biological activity of the sludge and improved the quality of purification in terms of dehydrogenase activity and chemical uptake of oxygen.

Appl Environ Microbiol, 1982 Sep, 44(3), 701 - 7
Fate and effects of methylene chloride in activated sludge; Klecka GM; Activated sludge obtained from a municipal wastewater treatment plant was acclimated to methylene chloride at concentrations between 1 and 100 mg/liter by continuous exposure to the compound for 9 to 11 days . Acclimated cultures were shown to mineralize methylene chloride to carbon dioxide and chloride . Rates of methylene chloride degradation were 0.14, 2.3, and 7.4 mg of CH2Cl2 consumed per h per g of mixed-liquor suspended solids for cultures incubated in the presence of 1, 10, and 100 mg/liter, respectively . Concentrations of methylene chloride between 10 and 1,000 mg/liter had no significant effect on O2 consumption or glucose metabolism by activated sludge . A hypothetical model was developed to examine the significance of volatilization and biodegradation for the removal of methylene chloride from an activated sludge reactor . Application of the model indicated that the rate of biodegradation was approximately 12 times greater than the rate of volatilization . Thus, biodegradation may be the predominant process determining the fate of methylene chloride in activated sludge systems continuously exposed to the compound.

Toxicol Lett, 1982 Jun, 12(1), 65 - 73
Toxic effects of animal manures and sewage sludge as supplementary feeds for the common carp . Cyprinus carpio; Wong MH et al.; Activated sludge, chicken manure and pig manure were tested for their toxic effects as supplementary feeds for the common carp, Cyprinus carpio . The acute toxicity test showed that animal manures were more toxic than activated sludge (e.g., 96-h LC50 values for pig manure and chicken manure were 0.55% and 0.29%, respectively, while no effective value was revealed for activated sludge) . This may be due to the inadequate processing of the manures which resulted in the release of harmful substances during decomposition . In general, body weights of all the fish fed the wastes decreased during the culture period . High heavy metal concentrations (Pb, Cu, Zn and Mn) were found accumulated in the flesh of the fish fed the wastes . It is suggested that waste materials should be pretreated and detoxified before using them as animal feeds.

Appl Environ Microbiol, 1982 May, 43(5), 1221 - 4
Evidence that microorganisms cause inactivation of viruses in activated sludge; Ward RL; Virus loss in activated sludge appeared to be caused by microorganisms . This conclusion is supported by the finding that poliovirus infectivity decreased during incubation in mixed-liquor suspended solids, primarily because of a sedimentable, heat-sensitive component . Furthermore, broth spiked with mixed-liquor suspended solids acquired antiviral activity during incubation.

Appl Environ Microbiol, 1982 Feb, 43(2), 371 - 7
Effect of UV light disinfection on antibiotic-resistant coliforms in wastewater effluents; Meckes MC; Total coliforms and total coliforms resistant to streptomycin, tetracycline, or chloramphenicol were isolated from filtered activated sludge effluents before and after UV light irradiation . Although the UV irradiation effectively disinfected the wastewater effluent, the percentage of the total surviving coliform population resistant to tetracycline or chloramphenicol was significantly higher than the percentage of the total coliform population resistant to those antibiotics before UV irradiation . This finding was attributed to the mechanism of R-factor-mediated resistance to tetracycline . No significant difference was noted for the percentage of the surviving total coliform population resistant to streptomycin before or after UV irradiation . Multiple drug resistance patterns of 300 total coliform isolates revealed that 82% were resistant to two or more antibiotics . Furthermore, 46% of these isolates were capable of transferring antibiotic resistance to a sensitive strain of Escherichia coli.

Appl Environ Microbiol, 1981 Nov, 42(5), 921 - 4
Positively charged filters for virus recovery from wastewater treatment plant effluents; Chang LT et al.; Positively charged Zeta Plus filters were used to concentrate enteroviruses from 19 liters of effluent from activated sludge units . Neither the addition of salts nor the acidification of the effluent was required for adsorption of viruses to the filters . Viruses adsorbed to the filters were eluted by treating the filters with a solution of 4 M urea buffered at pH 9 with 0.05 M lysine . Eluted viruses were concentrated into final volumes of 1 to 2 ml by using a two-step concentration procedure that employed inorganic and organic flocculation . Approximately 50% of the viruses added to effluents could be recovered in the final sample . The procedure was used to monitor effluents from activated sludge units at two wastewater treatment plants for the presence of enteroviruses.

Can J Microbiol, 1981 Mar, 27(3), 279 - 87
Effect of sludge type on poliovirus association with and recovery from sludge solids; Pancorbo OC et al.; Sludge type was found to affect the degree of association between seeded poliovirus type 1 (LSc) and sludge solids . The mean percent of solids-associated viruses for activated sludge mixed liquors, anaerobically digested sludges, and aerobically digested percent of solids-associated viruses for activated sludge mixed liquors, anaerobically digested sludges, and aerobically digested sludges was 57.2, 70.4, and 94.7, respectively . The degree of association between poliovirus and sludge solids was significantly greater for aerobically digested sludges than for the other two sludge types . Sludge solids associated viruses were eluted using 0.05 M glycine buffer, pH 10.5-11.0, and subsequently concentrated by organic flocculation . The effectiveness of the glycine method in the recovery of solids-associated viruses was also found to be affected by sludge type . Significantly lower mean poliovirus recovery was found for aerobically digested sludges (14.5%) than for mixed liquors or anaerobically digested sludges (72.3 and 60.2%, respectively) . The eluent used in the method was not as effective in dissociating the virus from aerobic sludge solids as it was for the other two sludge types . All other virus adsorption-elution steps of the method (i.e., virus concentration steps) were equally effective in poliovirus recovery for all three sludge types . It is suggested that future methods developed for the recovery of viruses from sludges be evaluated for the various sludge types likely to be tested.

Toxicol Lett, 1981 Feb, 7(4-5), 367 - 72
The uptake of zinc, lead, copper and manganese by carp fed with activated sludge; Wong MH et al.; The incorporation of 10 or 40% of activated sludge improved the growth rates of common carp, Cyprinus carpio, by comparison with those receiving a commercial fish feed (Tubifex worms) alone . The incorporation of 70% or 85% sludge, however, yielded very poor growth rates . The visceral organs of fish receiving 70 or 85% sludge contained 2 X zinc (Zn), 2.5 X copper (Cu) and 1.4 X manganese (Mn) of the control group.

Mikrobiologiia, 1981 Jan-Feb, 50(1), 21 - 8
{Properties of the obligate methylotroph Methylophilus methanolovorus}; Loginova NV et al.; A strain of obligate methylotrophic bacteria utilizing methanol as a sole source of carbon and energy was isolated from the activated sludge . The bacteria are strictly aerobic Gram-negative non-pigmented motile rods with a single polar flagellum . They do not form spores or capsules and have no complex intracytoplasmic membranes . They do not require vitamins and assimilate methanol via the hexulose phosphate pathway . The G+C content of DNA is 51.0 +/- 0.5 mole% . The optimal temperature is 30-38 degrees C, the optimal pH is 6.8-7.4 . The obligate dependence on C1-substrates but not on methane, as well as the absence of complex intracytoplasmic membranes, makes it possible to assign such methylotrophs to the genus Methylophilus nov . gen . The description of the new genus and species M . methanolovorus nov . gen., nov . sp . is presented.

J Environ Sci Health B, 1981, 16(1), 67 - 73
New methodology for the rapid detection of protein degradation in activated sludge; Fahey JW et al.; A rapid, inexpensive and sensitive technique has been developed for monitoring protein degradation in activated sludge . Spectrophotometric measurement of an enzymatically released dye was made within 5 h . The sensitivity of this technique was demonstrated by measuring the effects of HgCl2 (an anti-microbial agent) on protein degradation.

Appl Environ Microbiol, 1981 Jan, 41(1), 51 - 9
One-year survey of enteroviruses, adenoviruses, and reoviruses isolated from effluent at an activated-sludge purification plant; Irving LG et al.; Samples of raw sewage, primary effluent, and secondary effluent from a large activated-sludge purification plant near Melbourne (Victoria, Australia) were collected every second week for 1 year . Viruses were detected in all secondary effluent samples and in six of seven samples obtained after final chlorination . Adenoviruses (85% reduction) and reoviruses (28% reduction) were removed less efficiently by this treatment process than were enteroviruses (93% reduction) . In addition, 57 of 171 samples of effluent tested were positive for either adenoviruses or reoviruses, or both, when enteroviruses were not isolated . This clearly shows that the use of enteroviruses as sole indicators of viruses in water may miss up to one-third of instances of viral contamination . Enteroviruses and adenoviruses were isolated most frequently in HeLa-R cell cultures, whereas reoviruses were most often isolated in primary monkey kidney cells.

Aust Vet J, 1980 Oct, 56(10), 492 - 5
Preliminary observations on the removal of Taenia saginata eggs from sewage using various treatment processes; Arundel JH et al.; Cattle were grazed for four months on pasture irrigated by effluent from activated sludge plants, a trickling filter plant, from a lagooning process with raw sewage, and then killed and their heart, diaphragm, tongue, and muscles of their head and one forelimb were sliced and examined for Cysticercus bovis . None of the cattle grazed on pasture irrigated with effluent from lagooning were infected compared with 3.3% from the trickling filter plant, 9.0% and 12.5% from the two activated sludge plants and 30.0% of cattle on pastures irrigated with raw sewage . Of the 40 control calves killed at the time the test calves were placed on the various pastures, 2.5% were infected . It appears that modern sewage purification methods do not efficiently remove Taenia saginata from the final effluent and that prolonged settling is necessary before effluent is used to irrigate cattle pastures if C . bovis infection is to be reduced to very low levels.

Nord Vet Med, 1980 Jul-Aug, 32(7-8), 341 - 7
{Chlorinated hydrocarbons in sewage sludge from a plant in Oslo (author's transl)}; Kveseth NJ; Samples of sewage sludge from a plant in Oslo were analysed by gaschromatography for persistent chlorinated hydrocarbons . Polychlorinated bifenyls (PCBs) were found in all samples . In 1972 the mean value was 0.9 +/- 0.24 ppm PCBs, while the corresponding value two years later was 0.3 +/- 0.14 ppm . It is suggested that the observed decrease is connected with the restrictions of industrial use of PCBs from 1973 . The samples from 1974 were also analysed for phtalic acid esters . Residues of dimethyl-(DMP), diethyl-(DEP), dibutyl-(DBP) and diethylhexcyl-phtalate (DEHP) were found . Mean concentrations of DEHP and DBP were found to be 27 and 13 ppm respectively . The effect of the sludge treatment on PCBs was tested by comparing sewage coming into the plant with cleaned water leaving the plant . Between 50 and 85 percent of total PCBs remained in the water after the cleaning process . The total amount of PCBs in the sewage sludge per year was calculated to be about 2 kg.

Zentralbl Bakteriol Mikrobiol Hyg {B}, 1980, 171(6), 487 - 96
{Influence of different sampling systems on evaluation of bacteriological and virological performance for an activated-sludge treatment plant (author's transl)}; Hugues B et al.; Various quantitative evaluations of the performance of an activated-sludge treatment plant for viruses and bacteria removal and ameliorating physicochemical characteristics have been performed over a period of 24 hours, using successive and continuous samplings . The performance of the treatment plant evaluated using these two sampling systems shows no difference with the one obtained from punctual sampling . In every case, one can observe at the discharge a reduction amounting to 1 or 2 log . for the bacterial density and from 1/2 to 2 log . for the viral charge . Statistical study shows that whatever the sampling method used - punctual or successive and continuous over 24 hours - there is no fundamental difference between values of viral and bacterial densities . This comparison can only be established if a previous study has been made to determine the most representative hour to effect the punctual sampling.

Appl Environ Microbiol, 1980 Jan, 39(1), 253 - 60
Technique for determining total bacterial virus counts in complex aqueous systems; Ewert DL et al.; A direct method is described for measuring bacteriophage concentrations in complex aqueous systems . Conditions for sample clarification, phage recognition, and recovery were optimized . In contrast to the plaque assay, this procedure permits quantitation of total numbers of phages independent of bacterial host . Also, the modifications increase the sensitivity of the sedimentation assay, permitting detection of particles at a minimum concentration of 10(4) per ml . Maximal total phage concentrations in the aqueous phase of sewage and activated sludge mixed liquor were 1.3 x 10(6) and 4.3 x 10(7) per ml, respectively.

Acta Microbiol Pol, 1980, 29(4), 407 - 12
Application of semi-continuous culture on membrane filters for the study of activated sludge bacteria; Kunicka-Goldfinger W et al.; Bacterial population of activated sludge flocs from the petrochemical wastewater purification plant was studied by semi-continuous culture on membrane filters . Almost all (90%) of bacterial cells in the flocs were metabolically active . Only a small fraction of bacteria in the flocs was able to use phenol or ethylene glycol as the sole source of carbon . At higher concentrations of these compounds growth of the bacteria was strongly retarded.

Mikrobiologiia, 1979 Sep-Oct, 48(5), 785 - 92
{Blastobacter viscosus, a new species of methanol-utilizing autotrophic bacteria}; Loginova NV et al.; A strain of budding bacteria capable of autotrophic growth in the atmosphere of H2+O2+CO2 or in a medium with methanol was isolated from activated sludge . The cells are Gram negative nonmotile yellow pleomorphic rods which do not form rosettes . The bacterium is a strict aerobe . It utilizes a wide range of organic compounds (alcohols, sugars and organic acids) as the sources of carbon and energy . The G+C content of DNA is 66.3 +/- 0.9 mol % . Based on the study of morphological, cultural, and physiologo-biochemical properties, the strain has been assigned to the genus Blastobacter . A new species, Blastobacter viscosus sp . nov . different from other known blastobacteria in certain morphological and physiological properties, is described.

J Hyg (Lond), 1979 Apr, 82(2), 285 - 91
The influence of operating conditions of activated-sludge treatment on the behaviour of f2 coliphage; Balluz SA et al.; The behaviour of f2 coliphage during activated-sludge treatment was influenced by the temperature, flow-through-time, concentration of mixed liquor suspended solids and the virus load . The most sensitive way to detect behavioural changes was to examine the regression coefficients for the rate of uptake or loss of virus by the mixed liquor solids . This type of analysis revealed, for instance, high values when the solids concentration was high and even greater values occurred when high inocula were used . At high temperature the rate of loss of virus titre after inoculation had stopped was greater than the rate of uptake of virus during inoculation although in all other conditions uptake occurred at a greater rate than the loss of virus . The coefficients were relatively low when the flow rate was increased, when the temperature was low or when the inoculum was small . The distribution of virus between the solids and liquid fractions of the mixed liquor varied somewhat for all conditions but was notably different when (a) the plant was incubated at 5 degrees C when there was much less virus in the solids fraction than usual, and (b) when the inoculum was low and a much higher proportion of virus was found in the solids . The efficiency with which virus was removed across the plant was the least-sensitive determinant of viral behaviour and the value was about the same for most treatment conditions . However, low or high inocula did result in some increased or decreased removal of virus, respectively.

Acta Microbiol Pol, 1979, 28(3), 255 - 60
Effect of methyl alcohol and ethylene glycol on the work of activated sludge; Bieszkiewicz E et al.; The effect of methyl alcohol and ethylene glycol on the work of activated sludge grown in synthetic wastewater was investigated . Wastewater carrying these compounds could be purified by the activated sludge method, providing the concentration of methyl alcohol and glycol did not exceed 5,000 mg/l and 1,000 mg/l, respectively . At these values reduced purification efficiency, increased volumetric index of the sludge and changes in the structure of the activated sludge flocs could be observed.

Zentralbl Bakteriol {B}, 1978 Dec, 167(5-6), 478 - 88
Comparison of the toxicity of some metals and their tetracyanide complexes on the respiration of non acclimated activated sludges; Morozzi G et al.; The toxic effect of the metal ions of cadmium, zinc, nickel and mercury and their tetracyanide salt complexes, on the activated sludge not previously acclimated, has been studied . The evaluation of the effect was carried out using both the Warburg and TTC-method . The results obtained have shown that the toxicity of the cadmium and zinc complexes is higher than that of the corresponding metals, while the toxicity of Ni(CN)4(2-) is lower than that of the corresponding metals . No differences have been found between the effect of mercury and the corresponding tetracyanide complex . From the data obtained it appears that it is not possible to generalize about the biological effect of complexation with the CN- group, but it should be stated that, generally, there are substantial differences between metals and their cyanide complexes as far as toxicity for activated sludge is concerned.

Can J Microbiol, 1978 Jul, 24(7), 804 - 10
Characteristics of Thiobacillus thioparus and its thiocyanate assimilation; Katayama Y et al.; Thiocyanate-assimilatig bacterium, TK 21, was isolated from activated sludge used for the treatment of thiocyanate contained in coke-oven liquor . This organism oxidized thiosulfate and elemental sulfur, causing a decrease of pH of the medium . These facts indicated that it belongs to the genus Thiobacillus . Potassium thiocyanate (0.5 g/l) was completely assimilated during 60 h . Thiosulfate inhibited the assimilation of thiocyanate but elemental sulfur did not . This bacterium did not evolve cyanide as its oxidation product after the decomposition of thiocyanate . The isoalted bacterium was identified as Thiobacillus thioparus . Examination of the composition of cellular fatty acid of three strains of T . thioparus showed that they prossessed 3-hydroxy fatty acid of C10 and C12; saturated straight chains of C10, C12, C15, C16, C17, and C18; monounsaturated straight chains of C16 and C18; and cyclopropane acid of C17.

Appl Environ Microbiol, 1978 May, 35(5), 949 - 54
Microbial transformation of 14C-labeled 2,4,6-trinitrotoluene in an activated-sludge system; Carpenter DF et al.; The fate of 14C-labeled 2,4,6-trinitrotoluene (TNT) in an activated-sludge system was investigated . No {14C}TNT could be detected in the contents of an aerated reactor after 3 to 5 days of incubation . No significant 14CO2 was formed, and the radioactivity was about equally divided between the floc and the supernatant . The radioactive carbon present in the microflora was mainly associated with the lipid and protein components, but the characteristic constituents of these compounds (e.g., fatty acids and amino acids) were not radioactive . The major part of the 14C present in the lipid and protein fractions was found in precipitates that formed in both fractions . The solubility properties and infrared spectra of these precipitates suggested that they are macromolecular structures of the polyamide type formed by the reaction of TNT biotransformation products with lipids, fatty acids, and protein constituents of the microbial flora . This hypothesis is further supported by the correspondence of the infrared spectrum of the lipid precipitate with that of a model compound synthesized from TNT transformation products and lipid precursors . The resistance of these macromolecules to further biodegradation was paralleled by the reported resistance to microbial attack of polyamides containing similar linkages.

Can J Microbiol, 1978 May, 24(5), 618 - 9
Effect of sunlight on bacterial survival in transparent air samplers; Fedorak PM et al.; Two types of commercially available microbiological air samplers (model STA-203, New Brunswick Scientific and All-Glass Impingers, Millipore) were used outdoors at an activated sludge treatment plant . The recovery of viable particles with both instruments was increased three- to eight-fold by shielding the trapping medium from the sun during the sampling process.

J Hyg (Lond), 1978 Apr, 80(2), 237 - 42
The behaviour of f2 coliphage in activated sludge treatment; Balluz SA et al.; A model activated sludge treatment plant was used which was functionally very similar to a full-scale plant . It was inoculated with f2 coliphage and the titres of virus in the influent, the mixed liquor and the effluent were monitored regularly . The distribution of the virus in the solids and liquid fractions of the mixed liquor was in the ratio of 18:82 and 20.4% of the influent virus was recovered in the effluent . After inoculation was stopped the titre of virus in the solids fraction of the mixed liquor remained high and unaltered for up to 70 h, whereas the value for effluent reverted to the low background titre originally present . These results are discussed in relation to those reported for poliovirus and it is concluded that f2 coliphage is not a suitable model for studies of the behaviour of human enteroviruses.

Appl Environ Microbiol, 1978 Feb, 35(2), 360 - 3
Comparison between adsorption of poliovirus and rotavirus by aluminum hydroxide and activated sludge flocs; Farrah SR et al.; Adsorption of poliovirus and rotavirus by aluminum hydroxide and activated sludge flocs was studied . Both aluminum hydroxide and activated sludge flocs adsorbed greater amounts of poliovirus than rotavirus . Aluminum hydroxide flocs reduced the titer of poliovirus in tap water by 3 log10, but they only reduced the titer of a simian rotovirus (SA-11) in tap water by 1 log10 or less and did not noticeably reduce the number of human rotavirus particles present in a dilute stool suspension . Activated sludge flocs reduced the titer of added poliovirus by 0.7 to 1.8 log10 and reduced the titer of SA-11 by 0.5 log10 or less . These studies indicate that a basic difference in the adsorptive behavior of enteroviruses and rotaviruses exists and that water and wastewater treatment processes that are highly effective in removal of enteroviruses may not be as effective in removing other viral groups such as rotaviruses.

Arch Environ Contam Toxicol, 1978, 7(3), 301 - 15
Chlorination of benzidine and other aromatic amines an aqueous environments; Jenkins RL et al.; The fate of aniline, N,N-dimethylaniline and benzidine in chlorinated waters was investigated . Conditions were controlled to approximate the process chlorination of raw water supplies and wastewater secondary effluents . As the molar ratio, (Cl2)/(amine), was increased, amine depletions increased and leveled off at about (Cl2)/(amine) = 1 . Depletions in distilled water with "free" chlorine were somewhat higher than those in activated sludge/secondary effluent with combined chlorine . For each amine the number and type of products appeared to be independent of the water matrix and the ratio, (Cl2)/(amine) . For the monophenyl amines ring chlorination was a significant depletion pathway . Extended chlorination of aniline yielded a precipitated product, while the N-substituted amine, N,N-dimethylaniline did not yield a solid product . In contrast to the monophenyl amines, when benzidine (p,p'-diaminobiphenyl) was exposed to chlorinated waters, a solid product resulted immediately . Infra-red analysis of this product indicated a polymeric structure with no ring chlorination . GLC analysis of the chlorination supernatant showed no ring substituted isomers of benzidine.

Acta Microbiol Pol, 1978, 27(2), 155 - 60
The effect of cyclohexane derivatives on selection of bacterial groups forming activated sludge microflora; Bisz-Konarzewska A; The effect of cyclohexanol, cyclohekxanon and cyclohexylamine on the selection of bacteria in a model population composed of bacteria isolated from activated sludge was examined . The initial population consisted of both gram-positive and gram-negative bacteria . The latter, which accounted for 90-97% of the population, belonged mainly to three Pseudomonas groups and the Enterobacteriaceae, Vibrio-Aeromonas, Achromobacter-Alcaligenes and Flavobacterium groups . Seven day growth in medium containing cyclohexane derivatives caused pronounced qualitative changes in the population . The compounds favored the development of bacteria of the genus Pseudomonas and inhibited the growth of all other gram-negative bacteria . The direction of selection was independent of the type of cyclohexane derivative.

Acta Microbiol Pol, 1978, 27(2), 147 - 53
Effect of copper and tri- and hexavalent chromium on the work of an activated sludge; Bieszkiewicz E et al.; The effect of metals (Cu2+, Cr3+, Cr6+) on the work of an activated sludge grown in crude oil refining or synthetic wastes was examined . The activated sludge method was found to be applicable for the purification of wastes carrying up to 0.8 mgCu2+/1,15mgCr3+/1, or 20mgCr6+/1 . Higher concentrations of these metals inhibited the work of the activated sludge which was evident in inferior purification and reduced intensity of respiration of the activated sludge microorganisms.

Appl Environ Microbiol, 1977 Sep, 34(3), 315 - 9
Removal of Escherichia coli in wastewater by activated sludge; van der Drift C et al.; Removal of bacteria from wastewater treated with activated sludge was studied by the use of a streptomycin-resistant Escherichia coli strain . The removal appeared to be a biphasic process . A rapid sorption of bacteria to the sludge flocs took place in the first hour after seeding mixed liquor with E . coli . Thereafter, slower elimination of E . coli was observed . The latter process was due to predation on E . coli by ciliated protozoa . This was shown by: (i) appearance of fluorescent food vacuoles of ciliates when fluorescent E . coli cells were added to mixed liquor; (ii) inhibition of predation either in the presence of cycloheximide or under anaerobic conditions; and (iii) absence of predation in bulking and washed sludge.

Appl Environ Microbiol, 1977 Sep, 34(3), 308 - 14
Exocellular mucopolysaccharide closely related to bacterial floc formation; Tago Y et al.; A bacterium isolated from activated sludge formed a visible floc and also produced an exoenzyme that could bring about deflocculation . Scanning electron microscopic examination revealed that the cells were embedded in a film mesh in the floc, which disappeared after treatment with the deflocculating enzyme . Polysaccharides isolated from the floc were fractionated into three fractions by diethylaminoethyl-Sephadex A-25 column chromatography, whereas those from the free cells were fractionated into only two fractions . The missing fraction was a mucopolysaccharide composed of glucosamine, glucose, mannose, galactose, and rhamnose and was hydrolyzed to oligosaccharides by the deflocculating enzyme . The other two fractions were resistant to the enzyme . These results show that the mesh structure of the floc is dependent on a mucopolysaccharide hydrolyzed by the deflocculating enzyme.

J Hyg (Lond), 1977 Apr, 78(2), 165 - 73
The persistence of poliovirus of poliovirus in activated sludge treatment; Balluz SA et al.; A model activated sludge treatment plant was used which was functionally very similar to a full scale plant . It was inoculated with poliovirus either continuously or with a single dose and the amounts of virus in the influent, mixed liquor and effluent were monitored regularly . The distribution of the virus in the liquid and solid phases of the mixed liquor was very unequal with about 85% of the virus associated with the suspended solids fraction . Only small amounts of virus were recovered from the effluent and after inoculation was stopped virus rapidly became indetectable . The efficiency of the plant with regard to removal of virus was closely related to its capacity to remove suspended solids and the adsorption of virus to solids and its inactivation is briefly discussed.

Biotechnol Bioeng, 1977 Jan, 19(1), 43 - 53
Effects of quantitative shock loadings on the constant recycle sludge concentration activated-sludge process; Wong YK et al.; The reliability of the process of Ramanathau and Gandy (Biotechnical Bioeng., 13, 125 (1971) for the completely mixed activated-sludge process holding the recycle cell concentration, Xr, as a system constant with respect to step changes in hydraluic retention time was investigated . The experiments were run at initial dilution rates of 1/8, 1/6, 1/4, and 1/2 hr-1 treating a soft drink bottling wastewater . The influent substrate concentration was maintained at 1000 mg/liter chemical oxygen demand and the hydraulic recycle ratio at 0.3 . The recycle sludge concentration was maintained at about 7000 mg/liter . It was found that the system could accomodate hydraulic shock loads up to 200% positive changes and down to 50% negative changes without disruption of the effluent quality . Shorter retention time of the range studied, from 2 to 8 hr, has the advantage of shorter response time with respect to the response of the concentration of biological solids in the reactor.

Antonie Van Leeuwenhoek, 1977, 43(1), 19 - 29
Structural and physiological characteristics of some sheathed bacteria; Deinema MH et al.; The fine structure and growth of two gram-negative and two gram-positive strains of sheathed bacteria, isolated from activated sludge, have been studied . Their anatomy is quite different from Sphaerotilus natans . The cells are rectangular, tightly joined together, non-motile and enclosed by a sheath which is thin in the gram-negative strains and rather electron-dense in the two larger gram positive strains . The four strains grow slowly and form pink filamentous flocs in liquid media.

Can J Microbiol, 1976 Dec, 22(12), 1768 - 71
Morphological characteristics of a spirochete present in activated sludge; Deinema MH; A free-living spirochete has been found in the activated sludge of purification plants in Amsterdam . A partial enrichment of the spirochete could be obtained with a passage through a thin layer of water agar . The morphology of this spirochetal strain does not fit into one of the described genera in Bergey's Manual . The cells have many regular primary coils on which broad secondary coils are superimposed and the protoplasmic cylinder is tightly wound around an axistyle,

J Chromatogr, 1976 Nov 17, 128(1), 87 - 99
Determination of molecular-weight distribution of chitosan by high-performance liquid chromatography; Wu AC et al.; Optimal conditions for using high-performance liquid chromatography (HPLC) in the size exclusion mode have been determined for measuring the molecular-weight (MW) distribution of chitosan samples . Physical separation according to molecular size was accomplished on the stationary phase of glass supports having controlled pore sizes ranging from 2500 to 40 A . Selection of column combinations was based on the requirements to resolve the higher MW fraction of chitosan and to give a linear calibration curve within the required MW range . The best combination of glass pore sizes and column lengths in two foot sections joined sequentially was: 2500 A (2 ft.), 1500 A (4 ft.), 550 A (6 ft.), 250 A (2 ft), 100 A (2 ft.), and 40 A (2 ft.) . A loading study showed that an injection load of 500 mug, i.e . 100 mul at 5 g/l or 50 mul at 10 g/l (w/v), was the optimal load to give reproducible elution volumes, precision in quantitation, and minimum viscosity effects . The best calibration curve using defined dextran standards was obtained from the geometric mean of Mw (weight average MW) and Mn (number average MW) values and peak elution volumes . Precision in determining MW distribution of chitosan as well as dextran standards was better than 5% relative standard deviation, and the differences between these results and the manufacturer's data on the dextran standards were 6 to -17% . The MW distribution of a selected chitosan samples in 2% acetic acid thus determined was Mw = 2,055,000, Mn = 936,000, dispersity = 2.16, and the most abundant species was around 1,103,000 . Analysis time for the HPLC separation was less than 20 min per sample . Chitosan is an effective coagulating agent for the treatment of food processing wastes and activated sludge from biological treatment systems . It is manufactured from chitin in shrimp and crab wastes . The rapid methods developed here for determining the MW distribution of chitosan preparations will be used to optimize the manufacturing process and guide the selection of more effective chitosan products.

Appl Environ Microbiol, 1976 Oct, 32(4), 557 - 60
Biodegradability of {14C}methylcellulose by activated sludge; Blanchard FA et al.; Three Methocel methylcellulose ethers of 1.9 degree of substitution with {14C}methyl labels were shown to be biodegradable using batch-type activated sludge tests . The maximum rate for conversion to 14CO2, attained after 1 week, was only 0.62 mg of methylcellulose/g of mixed liquor volatile solids per day . In 20 days, 55 to 73% of the radioactivity had been removed from solution as 14CO2, and the suspended solids contained 12 to 15% of the original radioactivity . Only 4% of the original methylcellulose appeared to be polymeric after the 20-day period . Thin-layer chromatography of supernatant liquid indicated at least two degradation products.

Appl Environ Microbiol, 1976 Jul, 32(1), 33 - 7
Isolation of exocellular polymer from Zoogloea strains MP6 and 106 and from activated sludge; Farrah SR et al.; Exocellular polymer was isolated from zoogloeae of Zoogloea strains MP6 and 106 and from activated sludge flocs by blending samples with phosphate buffer and precipitation of solubilized polymer with cetyltrimethylammonium bromide . Samples of polymer from these sources were similar and yielded amino sugars as the principal components after acid hydrolysis.

Appl Environ Microbiol, 1976 May, 31(5), 746 - 9
Activated sludge degradation of adipic acid esters; Saeger VW et al.; The biodegradability of three aliphatic adipic acid diesters and a 1,3-butylene glycol adipic acid polyester was determined in acclimated, activated sludge systems . Rapid primary biodegradation from 67 to 99+% was observed at 3- and 13-mg/liter feed levels for di-n-hexyl adipate, di(2-ethylhexyl) adipate, and di(heptyl, nonyl) adipate in 24 h . When acclimated, activated sludge microorganisms were employed as the seed for two carbon dioxide evolution procedures, greater than 75% of the theoretical carbon dioxide was evolved for the three diesters and the polyester in a 35-day test period . The essentially complete biodegradation observed in these studies suggests that these esters would not persist when exposed to similar mixed microbial populations in the environment.

Appl Environ Microbiol, 1976 May, 31(5), 705 - 10
Airborne coliphages from wastewater treatment facilities; Fannin KF et al.; The emission (from wastewater treatment plants) of airborne coliphages that form plaques on two strains of Escherichia coli was investigated . Two activated-sludge and two trickling-filter plants were studied . Field sampling procedures used large-volume air samplers with recirculation devices . Coliphages were enumerated by a most-probable-number (MPN) procedure . Temperature, relative humidity, windspeed, and presence of sunlight were monitored . Concurrent samples of sewage were taken during each air-sampling run . Average coliphage levels in the airborne emissions of trickling-filter beds and activated-sludge units were 2.84 X 10(-1) and 3.02 X 10(-1) MPN/m3, respectively, for all positive observations, and sewage liquor concentrations from the sources were 4.48 X 10(5) and 2.94 X 10(6) plaque-forming units/liter, respectively, depending upon the E . coli host used for assay . This work establishes minimal airborne-coliphage concentrations from the plants studied . The procedures employed will be useful in evaluating the animal virus levels in these emissions.

Appl Environ Microbiol, 1976 Apr, 31(4), 536 - 43
Poliovirus survival and movement in a sandy forest soil; Duboise SM et al.; Movement of poliovirus I (Chat) through nonsterile core samples of a sandy forest soil was monitored, using several regimens of loading with either dechlorinated final effluent from an operating activated sludge treatment plant or distilled water . Stimulated cycles of rainfall and effluent applications, resulting in ionic gradients, were shown to affect virus movement . Such studies indicate that poliovirus applied in effluents may move considerable distances through this soil after rainfall . Survival of poliovirus in the soil at 4 and 20 C has been monitored for 84 days . During this period, the capacity of the virus to migrate is unchanged.

Z Naturforsch {C}, 1976 Mar-Apr, 31(3-4), 141 - 4
Fractionated precipitation of acid macropolyanions by dialysis, a simple method for the estimation of DNA in complex biological samples; Seibert G et al.; After efficient extraction by para-aminosalicylate, chopping, grinding and eventual sonication, the macropolyanions are transformed into their cetyltrimethylammonium salts . These have differing solubilities, strongly depending on ionic strength . The cationic detergent-macropolyanionic salts are solubilized by high salt concentration . Salt is then dialysed out, rendering the polyanions highly insoluble in a sequential fashion . The insolubilized components are determined quantitatively by monitoring turbidity, which in case of DNA is strictly proportionate to its concentration . This relation is not affected by other components . This makes DNA determination possible even in crude aqueous extracts . The method has been applied to different objects, such as bacteria, plants, animals, soil and activated sludge . The method may prove to be especially useful in research of environmental poisons e.g . in rivers, lakes or clarifiers.

Biotechnol Bioeng, 1976 Feb, 18(2), 145 - 65
The application of constant recycle solids concentration in activated sludge process; Bonotan-Dura FM et al.; The applicability of the model derived by Ramanathan and Gaudy (Biotechnol . Bioeng., 11, 207, (1969)) for completely mixed activated sludge treatment holding the recycle solids concentration as a system constant was investigated using an actual industrial organic wastewater . Short-term experiments were conducted at various dilution rates (1/8, 1/6, 1/4, 1/2, 1/1.5 hr-1) for two recycle solids concentration values (5000 and 7000 mg/liter) . The influent substrate concentration was maintained at 1000 mg/liter COD and the hydraulic recycle ratio- alpha, was kept at 0.3 . It was found that for bottling plant (Pepsi Cola) wastewaters, a steady state with respect to reactor biological solids and effluent COD, at different dilution rates, could be attained, lending experimental evidence to the assumption that a steady state could be reached in developing the model and also affecting the applicability of the model in industrial organic wastewater . The reactor biological solids and effluent COD calculated from the model closely agreed with the observed values at dilution rates lower than 0.5 hr-1 . Operation at dilution rates higher than 0.5 hr-1 will washout the biological solids from the reactor and the recycle substrate concentration will be apparent if the concentration of XR were not increased.

Appl Environ Microbiol, 1976 Jan, 31(1), 29 - 34
Biodegradation of phthalic acid esters in river water and activated sludge; Saeger VW et al.; The primary and ultimate biodegradability of phthalic acid, monobutyl phthalate, and five structurally diverse phthalic acid ester plasticizers in river water and activated sludge samples were determined via ultraviolet spectrophotometry, gas chromatography, and CO2 evolution . The compounds studied underwent rapid primary biodegradation in both unacclimated river water and acclimated activated sludge . When activated sludge acclimated to phthalic acid esters was used as the inoculum for the CO2 evolution procedure, greater than 85% of the total theoretical CO2 was evolved . These studies demonstrate that the phthalic acid ester plasticizers and intermediate degradation products readily undergo ultimate degradation in different mixed microbial systems at concentrations ranging from 1 to 83 mg/liter.

Acta Microbiol Pol, 1976, 25(3), 219 - 25
Studies on the biodegradation of nonionic surfactants applied in the polyester fiber industry . II . Effect of activated sludge load on microorganisms; Rzechowska E; The effect of selected nonionic surfactants Cirrasol FP, Cirrasol SF 200 and Cirrasol TCS on activated sludge organisms purifying wastes from the polyestre fibre industry was studied . The toxic effect of the mentioned surfactants towards bacteria, protozoa, rotifera and nematoda occurred at loads exceeding 0.32 mg surfactant/mg d.w./day and in periods of large fluctuations of the employed loads . Morphological changes of activated sludge flocs are also observed in similar conditions.

Acta Microbiol Pol, 1976, 25(3), 211 - 7
Studies on the biodegradation of nonionic surfactants applied in the polyester fiber industry . I . Activated sludge bacteria degrading the surfactants; Rzechowska E; The paper presents characteristics of 76 strains of bacteria capable of utilizing nonionic surfactants Cirrasol FP, Cirrasol SF 200 and Cirrasol TCS as the source of carbon . The strains were isolated from two activated sludges adapted to the purification of wastes containing the above compounds at concentration 150--200 mg/l . The isolated strains belonged to the genera: Achromobacter, Alcaligenes, Arthrobacter, Flavobacterium, Mycobacterium, Nocardia, Pseudomonas and Xanthomonas . With load 0.11 mg surfactant/mg d.w./day bacteria belonging to Alcaligenes were dominating . With load 0.18--0.31 mg surfactant/mg d.w./day microorganisms were dominated by Pseudomonas . The highest intensity of degradation of the studied surfactant was shown by species: Alcaligenes viscolactis, Nocardia blackwellii and Pseudomonas rathonis.

C R Acad Sci Hebd Seances Acad Sci D, 1975 Nov 3, 281(18), 1357 - 60
{Activated sludge activity: an easy test for inspection of biological purification plants}; Legeron JP et al.; The results of the enzymatic study of microbial dehydrogenases with triphenyl tetrazolium chloride (TTC) present the possibility of a new practical method which can be used in activated-sludge plants . The procedure has been modified, with regard to simplicity and low cost of operation.

Zentralbl Bakteriol {Orig B}, 1975 Sep, 161(1), 46 - 53
{Microbial contamination of air by activated sludge units (author's transl)}; Wanner HU; Measurements of the germ emissions in various activated sludge units with different ventilations systems have shown that the lowest density occurs with small bubble ventilation; with medium bubble and brush ventilation rather high values were measured; the spray devices used for foam elimination had a particularly unfavorable influence . In great germ densities above the pools (50-100 000 germs/m3) - depending on the weather - between 500 and 1500 germs/m3 were measured at a distance of 50 and 100 meters . At distances of 200 and 400 m the number of germs was about the same as normally measured in the outside air (100-500 germs/m3) . In a closed pool altogether considerably higher values were measured: In the immediate neighbourhood of the activated sludge unit they amounted to abt . 10 000-25 000 germs/m3; in the hall 3000-4000 germs/m3 were measured, whereby the part of coliform bacteria amounted to 1-2% and that of enterococci to 2-4% . It has to be taken into account that besides the measured intestinal flora further pathogenous agents are present in the aerosols . In closed units, therefore, a greater risk of aerogenous infections exists, whereas in open-air pools this danger can be judged as very small.

Arch Microbiol, 1975 Aug 28, 104(3), 279 - 83
Competitive ability of amylolytic bacteria in activated sludge; Verstraete W et al.; Shifts were induced into the microbial community of activated sludge by the pulse addition of soluble starch . The subsequent changes of amylolytic and proteolytic microbial populations were recorded . Four amylolytic strains were isolated and characterized with regard to carrying capacity, specific surface and growth kinetics . The competitive ability of these strains was studied by means of two-member competition experiments . These experiments were analysed according to the Lotka-Volterra model and the de Wit method . The different results obtained suggest that the dominance of the amylolytic Pseudomonas sp . (code 01) is based on a combined occurrence of high amylolytic activity, large relative cell surface, high maximum specific growth rate and reduced sensitivity towards associated proteolytic populations.

Appl Microbiol, 1975 Jul, 30(1), 132 - 9
Fluorescent-antibody study of natural finger-like zoogloeae; Farrah S et al.; Fluorescent-antibody techniques using Zoogloea ramigera 106 antiserum were used to study fresh activated sludge flocs and finger-like zoogloeae in the microbial film that developed over stored samples of activated sludge . Few cells in fresh activated sludge reacted positively with the fluorescein-labeled antiserum . Finger-like zoogloeae containing reactive cells were readily observed in the microbial film layer over stored activated sludge . Certain of the naturel finger-like projections were entirely composed of cells that reacted positively to the labeled Z . ramigera 106 antiserum, whereas other projections were devoid of reactive cells.

J Infect Dis, 1975 Jun, 131(6), 658 - 64
Absence of hepatitis B antigens from feces and sewage as a result of enzymatic destruction; Grabow WO et al.; Hepatitis B surface antigen (HBs Ag) was not detected in sewage by means of a sensitive affinity chromatography method combined with radioimmunoassay . The antigen was also absent from the feces and urine of 23 patients with HBs Ag antigenemia; this observation indicates that HBs Ag is rarely discharged into sewage . The absence of HBs Ag from feces is ascribed to antagonists of an enzymatic nature or to carboxypeptidase A, which destroys the antigen . Antagonists with similar effects were produced by three species of Pseudomonas but were not produced by various other bacteria . HBs Ag was also destroyed by two subtilisin enzymes . When hepatitis B sera were incubated with these enzymes or with the antagonists, small spherical particles, tubules, and the coats of Dane particles disappeared first, and Dane cores disappeared later . Although sewage or activated sludge did not affect the stability of HBs Ag, the results indicate that even Dane cores are not excreted in feces and that sewage plays a negligible role in the spread of HBs Ag, Dane cores, and viral hepatitis type B.

Prikl Biokhim Mikrobiol, 1975 May-Jun, 11(3), 367 - 73
{Metabolism of monocarbon compounds during biological purification of sewage waters}; Makeeva EN et al.; Pathways and rates of metabolism of three 14C1-compounds (methanol, formaldehyde, and formic acid) were investigated by means of the heterogeneous population of activated sludge microorganisms . For the above microbial population formaldehyde was the primary or preferential substrate . During an hour aeration it was processed by activated sludge 6 times faster than by sodium formiate and 2 times faster than by methanol . The basic pathways of its transformation were oxidation via formiate to CO2 with its partial reutilization and direct incorporation into the sludge biomass via the primary formation of serine . An addition of methanol increased the incorporation of 14C-formadehyde into biomass and decreased the formation of free 14CO2 . The main mechanism of the transformation of 14C-formiate in activated sludge was its oxidation to CO2 . An addition of methanol and formaldehyde induced no essential changes in the rate or pattern of their metabolism.

Environ Lett, 1975, 9(1), 75 - 90
Metal concentrations in the sewage, effluents, and sludges of some southern Ontario wastewater treatment plants; Oliver BG et al.; Aluminum, barium, berylliu, bismuth, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, molybdenum, nickel, silver, strontium, vanadium and zinc concentrations in the sewage, effluents and sludges of ten southern Ontario wastewater treatment plants are reported . The efficiency for metal removal by a conventional activated sludge plant was determined . The effect of metal concentrations in receiving waters from residual metals in sewage effluents is discussed . The environmental hazards of disposing of sewage sludges with high metal content on agricultural land is considered.

Environ Qual Saf Suppl, 1975, 4, 180 - 90
Photochemical and biological degradation of water-soluble FWAs; Guglielmetti L; A study was made of the photochemical and biological degradation of two water-soluble fluorescent whitening agents (FWAs): the disodium 4,4'-bis(2-sulfostyryl)-biphenyl (1) and the disodium 4,4-bis ({4-anilino-6-(N-methyl-N-2-hydroxyethyl)amino 1,3,5-triazin-2-yl}amino)stilbene-2,2'-disulfonate (2) . Each represents an important class of detergent fluorescent whitening agents . The photochemical degradation of (1) was studied by irradiating diluted aqueous solutions of this compound with a low intensity high pressure mercury vapor lamp . From the intermediate, as well as the ultimate photodegradation products isolated, it can be infered that photodegradation of (1) followed the proposed scheme . The biologica degradation of (1) and (2) by activated sludge under aerobic conditions was studied using equipment similar to that proposed by the OECD for determining the biodegradation of anionic synthetic surface active agents . Under the conditons applied, both FWAs were slowly biodegraded, within 30 days, whereas the photodegradation products of (1) were completely biodegraded within 14 days.

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