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At least 19 recordsLinked to original sources

A comparison of salmonella serotypes found in the faeces of gulls feeding at a sewage works with serotypes present in the sewage.

The numbers of salmonella serotypes in raw sewage, sewage sludge and final effluent at a sewage treatment works were determined. Resting gulls which had previously been feeding on the sewage were disturbed and individual faecal samples tested for the presence of salmonellae. The serotypes were compared with those in the sewage. Six serotypes were isolated from the sewage, Salmonella stanley being found in all types of samples. Eleven of the twenty gull faeces samples were positive for salmonellae, a carriage rate of 55%. Seven serotypes were found, S. stanley being most frequent. Three serotypes were found in both sewage and gull faeces.

Animals↗

Utilization of night-soil, sewage, and sewage sludge in agriculture.

The author reviews the agricultural use of night-soil, sewage, and sewage sludge from two points of view: the purely agricultural and the sanitary.Knowledge of the chemistry and bacteriology of human faecal matter is still rather scant, and much further work has to be done to find practical ways of digesting night-soil in a short time into an end-product of high fertilizing value and free of pathogens, parasites, and weeds.More is known about sewage and sewage sludge, but expert opinion is not unanimous as to the manner or the value of their use in agriculture. The author reviews a number of studies and experiments made in many countries of the world on the content, digestion, composting, agricultural value, and epidemiological importance of sewage and sewage sludge, but draws from these the conclusion that the chemistry, biology, and bacteriology of the various methods of treatment and use of waste matter need further investigation. He also considers that standards of quality might be set up for sludge and effluents used in agriculture and for water conservation.

Agriculture↗

The dissipation of phosphorus in sewage and sewage effluents.

Of the 41 kt of phosphorus reaching the sewage works in England and Wales 15 kt is removed in sewage sludge and the remainder is disposed of to rivers. 60% of the sewage sludge is now used as fertilizer and this proportion will no doubt increase in the future. The total use of sewage sludge, however, represents only about 5% of the current annual usage of artificial phosphorus fertilizer. At present there is no general economic incentive to make better use of the phosphorus in effluents. Phosphorus removal is expensive--about 2--3 pence/m3. If all the sewage effluents in England and Wales were to be so treated the cost would be about 100--150 million pounds annually, that is about 50% of the present costs of sewage treatment. In certain cases, but rarely in the UK, phosphate is removed, not to conserve phosphorus but to minimize the problems it creates in the environment. The phosphorus removed has little value as fertilizer. Alternative methods of using the phosphorus in effluents by the production and harvesting of crops of algae or aquatic plants have so far proved uneconomic. However, these methods need to be reviewed periodically as they may in the future become economically more attractive, especially in warmer climates where plant growth can be maintained throughout the year.

Adult↗

[Importance of the results of a virological examination of sewage. A quantitative evaluation of the finding of enteroviruses in sewage].

In order to evaluate quantitatively the effectiveness of virological examinations of sewage, a labeled virus in a dose of 7.5X10(9) PFU was introduced into the canalization system of a community. Such an amount of virus could be found in the canalization system if 5--10% of the residents would excrete it simultaneously. The labeled virus was selectively detected in the community sewage. This procedure has demonstrated that the routine methods for sewage collection, specimen treatment, and virus isolation permit virus detection when 5--10% of this virus excretors are available. The labeled virus entered the canalization system most actively within the first 2 hours after administration, then its amount declined, and within 24 hours ceased. The labeled virus was found on all swabs which were in the sewage flow since the time of administration to the 7th day. The maximum amount of virus was found on the swab which was in the sewage flow for the first 2 hours after virus administration. By 7 days the amount of labeled virus on swabs decreased 10-fold. Under experimental conditions, in sewage kept at 25 degrees C enteroviruses of the group of poliomyelitis, ECHO, and Coxsackie had approximately similar inactivation rate (0.16--0.22 Ig TCD50 per day) and the half-life period (1.3 days), that is, in 7 days the virus titer on a swab should decline by 1.0--1.5 Ig TCD50.

Enterovirus↗

Counting cytopathogenic virus adsorbed to cellulose nitrate membrane filters as a simple method for counting viruses in raw sewage and sewage effluents.

Using the VIRMETADEN (acronym derived from virus adsorption enumeration) method to count cytopathogenic viruses adsorbed to cellulose nitrate membrane filters from prefiltered and decontaminated sewage samples was shown to be feasible. The numbers of naturally occurring enteroviruses recovered by the VIRMETADEN method were significantly higher than those obtained by standard plaque assay. For prefiltration of sewage samples, low protein binding polyvinylidene fluoride (PVDF) membranes of 0.65 and 5 microm pore size proved to be at least as good as prefilters used previously, both in the volume that could be filtered and in the low virus retention. Regarding decontamination, 0.22 microm pore size PVDF membranes were as good as chloroform treatment. Alternatively, decontamination with 0.05% phenol followed by filtration through 0.65 microm PVDF membrane filters proved to be an excellent method for clarifying and decontaminating the sample prior to enumerating viruses using the VIRMETADEN method. It allows good recovery and greater decontaminated sample volumes. The application of VIRMETADEN to decontaminated raw sewage and secondary effluent gave recoveries of approximately 100% of vaccinal polioviruses seeded in sewage. The advantage of this approach is that the same method is applicable to sewage affluents and effluents with a simple and fast method, which implies lower material and labour costs.

Adsorption↗

The occurrence and significance to animal health of Leptospira, Mycobacterium, Escherichia coli, Brucella abortus and Bacillus anthracis in sewage and sewage sludges.

Samples of sewage, sewage sludge and sewage effluent from one or more of four sewage treatment plants were examined for the presence of Leptospira, Mycobacterium, Escherichia coli, Brucella abortus and Bacillus anthracis. Brucella abortus and Bacillus anthracis were not isolated. Eleven strains of E. coli potentially enteropathogenic for calves or piglets, eight pathogenic strains of Mycobacterium and one patho;genic Leptospira strain were isolated from 101, 189 and 189 samples respectively. Sewage sludge is no;t considered to play a major part in the epidemiology of disease caused by these organisms.

Animal Diseases↗

[Importance of the results of a virological examination of sewage. A comparison of the series of enteroviruses isolated from sewage and from the feces of virus excreters].

Simultaneous examinations for the presence of enteroviruses were carried out on sewage of the central aeration station, periferal collectors of the most populous institutions, preschool children's institutions as well as feces of children attending these institutions in a community of urban type. A high degree of coincidence of spectra of enteroviruses isolated from sewage of the central station, periferal collectors, sewage of children's institutions, and from the feces of most virus excretors was demonstrated. No enteroviruses found in occasional virus excretors were detected in sewage. Enteroviruses were regularly found in sewage of periferal collectors if approximately 10% of children excreted a certain virus type simultaneously.

Carrier State↗

Sources, behaviour and fate of organic contaminants during sewage treatment and in sewage sludges.

Recent concern over the environmental impact of sewage sludge application to agricultural land has drawn particular attention to the wide range of organic contaminants that may enter sewage treatment processes and persist in biosolids for disposal. This paper discusses processes influencing the fate and behaviour of organic contaminants during wastewater treatment and reviews literature relating to specific contaminants identified in sewage sludge. The difficulties associated with the development of specific methods for the analysis of trace residues of organic contaminants in complex matrices such as sludge are discussed. Some potential issues relating to impact of sewage sludge disposed to agricultural land are also considered.

Hydrocarbons, Chlorinated↗

Adaptation of the CAS test system and synthetic sewage for biological nutrient removal. Part I: development of a new synthetic sewage.

A new synthetic medium has been developed for routine use in laboratory-scale sewage treatment simulation and biodegradation tests, such as OECD guideline 302A & 303A or ISO method 11733. The new medium, Syntho, was designed to meet the following objectives: 1) to be more representative of real sewage than the existing standard OECD synthetic sewage, 2) the COD:N:P ratio and mineral composition must allow a good degree of biological nutrient (N, P) removal, and 3) the medium should result in stable unit operation, including good sludge settling and minimal need for control actions. The IAWQ Activated Sludge Model No. 2 (ASM2,) was used to help design the medium and predict reactor performance for different possible media compositions. The results obtained with Syntho indicate that Continuous Activated Sludge (CAS) units with or without nutrient removal can be operated routinely on this feed. The new medium was also characterized by means of a respiration test. The different influent fractions applied in the model were validated, and a respiration profile indicated that Syntho is a close approximation of real sewage.

Biodegradation, Environmental↗

The occurrence and significance to animal health of salmonellas in sewage and sewage sludges.

A total of 882 samples of settled sewage, sewage sludges and final effluents from eight sewage treatment plants were examined for the presence of salmonellas. Of these samples 68% were positive, isolations being made most frequently from settled sewage (85%), raw sludge (87%) and anaerobically digested sludge (96%). Fewer isolations were made from final effluent (24%) and processed sludges (58%). Samples usually contained less than 200 salmonellas/100 ml and arguments are presented that such concentrations should not lead to disease in animals if suitable grazing restrictions are followed.

Animals↗

The importance of pathogenic organisms in sewage and sewage sludge.

Deficient sanitation poses a serious threat to human and animal health, involving complex relationships between environments, animals, refuse, food, pathogens, parasites, and man. However, by sanitizing and stabilizing the organic matter of sewage sludge, agriculture can utilize it to maintain soil, water, and air quality. As ingredients in soil amendments, such bioresidues are a source of nutrients for plants. Stabilization and sanitation of sewage sludge safely couple its recycling and disposal. This coupling becomes increasingly important as economic and environmental constraints make strategies for waste disposal more difficult to apply. The occurrence of viruses, bacteria, yeasts, fungi, and zooparasites in sewage sludge is reviewed in this article, and consequential epidemiologic concerns that arise from sewage sludge recycling is also addressed.

Agriculture↗

Distribution of sewage indicated by Clostridium perfringens at a deep-water disposal site after cessation of sewage disposal.

Clostridium perfringens, a marker of domestic sewage contamination, was enumerated in sediment samples obtained from the vicinity of the 106-Mile Site 1 month and 1 year after cessation of sewage disposal at this site. C. perfringens counts in sediments collected at the disposal site and from stations 26 nautical miles (ca. 48 km) and 50 nautical miles (ca. 92 km) to the southwest of the site were, in general, more than 10-fold higher than counts from an uncontaminated reference site. C. perfringens counts at the disposal site were not significantly different between 1992 and 1993, suggesting that sewage sludge had remained in the benthic environment at this site. At stations where C. perfringens counts were elevated (i.e., stations other than the reference station), counts were generally higher in the top 1 cm and decreased down to 5 cm. In some cases, C. perfringens counts in the bottom 4 or 5 cm showed a trend of higher counts in 1993 than in 1992, suggesting bioturbation. We conclude that widespread sludge contamination of the benthic environment has persisted for at least 1 year after cessation of ocean sewage disposal at the 106-Mile Site.

Clostridium perfringens↗

A note on antibiotic resistance in the bacterial flora of raw sewage and sewage-polluted River Tigris in Mosul, Iraq.

Polluted water samples collected from the River Tigris in the vicinity of a raw sewage outfall were examined for the incidence of antibiotic resistance among coliform bacteria on three occasions during 1983. Eighty percent or more of the coliform bacteria were resistant to one or more antibiotics. At the same time, raw sewage samples were examined for the incidence of antibiotic-resistant bacteria, and Escherichia coli, Pseudomonas spp. and Staphylococcus spp. were selected for sensitivity testing. Collectively, more than 90% of the 480 strains of the three organisms were resistant to one or more antibiotics. The minimal inhibitory concentration (MIC) of ampicillin for twenty-nine strains including coliforms, E. coli, Klebsiella sp., Serratia sp., Ps. aeruginosa, Pseudomonas sp., Micrococcus sp., Staph. aureus, Streptococcus faecalis and Bacillus sp. from raw sewage and polluted River Tigris water was determined and that for Ps. aeruginosa was 250 micrograms/ml. The high incidence of antibiotic-resistant bacteria in natural waters could be related to the widespread use of antibiotics in this locality.

Anti-Bacterial Agents↗

Enumeration of salmonellas by most probable number method from sewage and sewage-polluted natural waters, comparing the use of preenrichment versus direct enrichment in NR10 at different temperatures.

Crude sewage and sewage-contaminated natural waters were analysed for the presence of Salmonella by Most Probable Number Procedures, Direct enrichment in NR10 at 37 degrees C and 43 degrees C was compared with preenrichment in buffered peptone water at these two temperatures, followed by selective enrichment in NR10 at 37 degrees C and 43 degrees C. The growth of competing bacteria on Hektoen agar plates was also recorded and quantified. Direct enrichment in NR10 gave higher numbers in both types of waters. The temperature of 37 degrees C was more favourable for the less heavily contaminated waters, whereas 43 degrees C was more efficient for crude sewage. The growth of competing bacteria was restricted at 43 degrees C and enhanced at 37 degrees C. With direct enrichment in NR10/43 degrees C, pure Salmonella cultures can be obtained after 48 h incubation.

Culture Media↗

Virus isolations from sewage and from a stream receiving effluents of sewage treatment plants.

In order to detect viruses in sewage or streams, it is first necessary to concentrate the virus present in the fluid sample. Available methods are not readily manageable for concentrating virus from large volumes of fluid, and have not always yielded high recovery rates. In the study described in this paper, a method for concentration of viruses by adsorption on insoluble cross-linked maleic anhydride polyelectrolytes has been utilized to survey the viral flora of sewage and of a stream receiving sewage effluents, in a residential area of Houston, Texas. On a single day the virus flow at different points along the stream varied from 304 000 to 6 014 000 PFU/min. From 84 samples each of 1 US gal, 14 520 isolates were obtained, chiefly echovirus type 7 and polioviruses of all 3 types, some of them with characteristics of virulent wild strains. With virus isolation rates as high as those achieved, it is now possible to monitor virus in natural waters more effectively.

Enterovirus B, Human↗

Toxicologic studies associated with the agricultural use of municipal sewage sludge and health effects among sewage treatment plant workers.

The proposed use of municipal sewage sludges as soil amendments on agricultural land involves potential health risks. Sludges may contain toxic heavy metals, synthetic organics, and pathogens. Studies of animals inhabiting sludge-amended soils, or foraging on crops grown on such soils, have shown an increased deposition of cadmium and polychlorinated biphenyls in animal tissues, hepatic microsomal enzyme induction, altered blood profiles, appearance of mutagens in blood and excreta, and lowered feed intake, feed efficiency, and milk production. Epidemiologic evidence of possible adverse health effects among sewage plant workers exposed to aerosolized pathogens or synthetic organic vapors during wastewater treatment or land spreading of sludge is still inconclusive. Other possible deleterious environmental effects include pollution of groundwater and toxicity to birds consuming worms or insects inhabiting sludge-treated soils.

Agriculture↗

A note on antibiotic-resistant Escherichia coli in adult man, raw sewage and sewage-polluted River Tigris in Mosul, Nineva.

A total of 600 isolates of Escherichia coli were isolated, over a 9 month period during 1984, from healthy human adults, raw sewage and the sewage-polluted River Tigris in Nineva. Over 90% of these organisms were E. coli type 1, but only 8.3% could be serogrouped as enteropathogenic E. coli. Resistance of these organisms to 11 antimicrobial drugs was assessed. Over 40% were antibiotic-resistant and of these 77.1% were resistant to more than one antibiotic. The minimal inhibitory concentration of ampicillin for 193 selected strains from the various sources was determined and ranged from less than 0.625-greater than 160 micrograms/ml. The high incidence of antibiotic-resistant E. coli in this locality and the possible implications to human health are discussed.

Adult↗

A note on the use of Rappaport-Vassiliadis medium (R10/RV) for the isolation of salmonellas from sewage and sewage sludges.

The use of a modified Rappaport broth for the selective enrichment of salmonellas in sewage sludge is described. Comparative trials were carried out using Muller Kauffman--Tetrathionate (MKT) broth and Rappaport-Vassiliadis (R10/RV) medium for selective enrichment. Results have indicated that R10/RV broth is more selective and is to be preferred for routine monitoring.

Culture Media↗