scholarly journals Comparison of BGM and PLC/PRC/5 Cell Lines for Total Culturable Viral Assay of Treated Sewage

2008 ◽  
Vol 74 (9) ◽  
pp. 2583-2587 ◽  
Author(s):  
Roberto A. Rodríguez ◽  
Patricia M. Gundy ◽  
Charles P. Gerba

ABSTRACT The objective of this study was to compare PLC/PRF/5 and BGM cell lines for use in a total culturable viral assay (TCVA) of treated sewage effluents. Samples were collected before and after chlorination from an activated sludge wastewater treatment plant and from the effluent of a high-rate enhanced flocculation system, followed by UV light disinfection. Cell monolayers were observed for cytopathic effect (CPE) after two passages of 14 days each. Monolayers exhibiting viral CPE were tested for the presence of adenoviruses and enteroviruses by PCR or reverse transcription-PCR. Eight percent of the samples exhibited CPE on BGM cells, and 57% showed CPE on PLC/PRF/5 cells. Only enteroviruses were detected on the BGM cells, while 30% and 52% of the samples were positive for enteroviruses and adenoviruses, respectively, on the PLC/PRF/5 cells. Thirty percent of the samples were positive for both adenoviruses and enteroviruses in chlorinated activated sludge effluent. Thirty percent of the samples were positive for adenoviruses in the UV treatment effluent, but no enteroviruses were detected. In conclusion, the PLC/PRF/5 cells were more susceptible than BGM cells to viruses found in treated sewage. The use of BGM cells for TCVA may underestimate viral concentration in sewage effluent samples. The PLC/PRF/5 cells were more susceptible to adenoviruses, which is important in the evaluation of UV disinfection systems because adenoviruses are highly resistant to UV inactivation.

1990 ◽  
Vol 22 (7-8) ◽  
pp. 131-138
Author(s):  
Ahmed Fadel

Many of Egypt's cities have existing treatment plants under operation that have been constructed before 1970. Almost all of these treatment plants now need rehabilitation and upgrading to extend their services for a longer period. One of these plants is the Beni Suef City Wastewater Treatment Plant. The Beni Suef WWTP was constructed in 1956. It has primary treatment followed by secondary treatment employing intermediate rate trickling filters. The BOD, COD, and SS concentration levels are relatively high. They are approximately 800, 1100, and 600 mg/litre, respectively. The Beni Suef city required the determination of the level of work needed for the rehabilitation and upgrading of the existing 200 l/s plant and to extend its capacity to 440 l/s at year 2000 A description of the existing units, their deficiencies and operation problems, and the required rehabilitation are presented and discussed in this paper. Major problems facing the upgrading were the lack of space for expansion and the shortage of funds. It was, therefore, necessary to study several alternative solutions and methods of treatment. The choice of alternatives was from one of the following schemes: a) changing the filter medium, its mode of operation and increasing the number of units, b) changing the trickling filter to high rate and combining it with the activated sludge process, for operation by one of several possible combinations such as: trickling filter-solids contact, roughing filter-activated sludge, and trickling filter-activated sludge process, c) dividing the flow into two parts, the first part to be treated using the existing system and the second part to be treated by activated sludge process, and d) expanding the existing system by increasing the numbers of the different process units. The selection of the alternative was based on technical, operational and economic evaluations. The different alternatives were compared on the basis of system costs, shock load handling, treatment plant operation and predicted effluent quality. The flow schemes for the alternatives are presented. The methodology of selecting the best alternative is discussed. From the study it was concluded that the first alternative is the most reliable from the point of view of costs, handling shock load, and operation.


1994 ◽  
Vol 30 (6) ◽  
pp. 31-40 ◽  
Author(s):  
Hiroyshi Emori ◽  
Hiroki Nakamura ◽  
Tatsuo Sumino ◽  
Tadashi Takeshima ◽  
Katsuzo Motegi ◽  
...  

For the sewage treatment plants near rivers and closed water bodies in urbanized areas in Japan and European countries, there is a growing demand for introduction of advanced treatment processes for nitrogen and phosphorus from the viewpoints of water quality conservation and environmental protection. In order to remove nitrogen by the conventional biological treatment techniques, it is necessary to make a substantial expansion of the facility as compared with the conventional activated sludge process. In such urbanized districts, it is difficult to secure a site and much capital is required to expand the existing treatment plant. To solve these problems, a compact single sludge pre-denitrification process using immobilized nitrifiers was developed. Dosing the pellets, which are suitable for nitrifiers growth and physically durable, into the nitrification tank of single sludge pre-denitrification process made it possible to perform simultaneous removal of BOD and nitrogen in a retention time equal to that in the conventional activated sludge process even at the low water temperature of about 10 °C. The 3,000 m3/d full-scale conventional activated sludge plant was retrofitted and has been successfully operated.


2004 ◽  
Vol 50 (7) ◽  
pp. 19-26 ◽  
Author(s):  
H. Kroiss ◽  
F. Klager ◽  
S. Winkler ◽  
G. Wandl ◽  
K. Svardal

The Main Treatment Plant of Vienna is in extension for 4 million p.e. and very stringent nutrient removal requirements. The existing high rate BOD removal activated sludge plant (in operation since 1980) is extended by a second stage activated sludge plant and a newly developed flow scheme for nitrogen removal optimisation adaptable to the temperature variations over the year. For this plant pilot investigations have been performed for the development of a specific mathematical model (ASMV) and a specific aeration control strategy. The civil work of the extension is already finished and the installation of the equipment has started. Operation should start in 2004. The whole project will cost about €264 million of which about one half is for civil work. The effluent standards correspond to the requirements for sensitive areas in EU Directive for Municipal Waste Water. The raw primary and excess sludge are incinerated after thickening and dewatering. This paper tries to condense the already existing literature with the construction progress and the cost situation.


2013 ◽  
Vol 12 (3) ◽  
pp. 404-409 ◽  
Author(s):  
H. Childress ◽  
B. Sullivan ◽  
J. Kaur ◽  
R. Karthikeyan

The ubiquitous use of antibiotics has led to an increasing number of antibiotic-resistant bacterial strains, including strains that are multidrug-resistant, pathogenic, or both. There is also evidence to suggest that antibiotic resistance genes (ARGs) spread to the environment, humans, and animals through wastewater effluents. The overall objective of this study was to investigate the effect of ultraviolet (UV) light disinfection on antibiotic-resistant bacteria. Wastewater effluent samples from a wastewater treatment plant (WWTP) in Texas were evaluated for differences in tetracycline-resistant bacteria before and after UV treatment. The effects of photoreactivation or dark repair on the reactivation of bacteria present in WWTP effluent after UV disinfection were also examined. Culture-based methods were used to characterize viable heterotrophic, tetracycline-resistant heterotrophic, Escherichia coli, and tetracycline-resistant E. coli bacteria present before and after UV treatment. UV disinfection was found to be as effective at reducing concentrations of resistant heterotrophs and E. coli, as it was at reducing total bacterial concentrations. The lowest survival ratio following UV disinfection was observed in tetracycline-resistant E. coli showing particular susceptibility to UV treatment. Photoreactivation and dark repair rates were found to be comparable to each other for all bacterial populations.


2014 ◽  
Vol 878 ◽  
pp. 702-707 ◽  
Author(s):  
Chang Liu ◽  
Ping Zeng ◽  
Yong Hui Song ◽  
Jian Guang Cheng ◽  
Chao Wei Zhu ◽  
...  

Three kinds of surplus activated sludge were pretreated by alkali and combination of alkali and ultrasonic. The changes of PO43-P, TP, SCOD, TOC, TS, VS before and after pretreatment were investigated. The results showed that phosphorus and organic matter could be released into supernatant both by alkali and ultrasonic. The surplus activated sludge from municipal wastewater treatment plant was easier to be broken than that from pharmaceutical wastewater treatment plant. The activated sludge from Qinghe wastewater treatment plant could be selected for further phosphorus recovery since the largest quantity of phosphorus release and the lowest organic matter release ratio among the three kinds of surplus activated sludge.


2016 ◽  
Vol 23 (3) ◽  
pp. 461-471 ◽  
Author(s):  
Roman Babko ◽  
Tatiana Kuzmina ◽  
Zbigniew Suchorab ◽  
Marcin K. Widomski ◽  
Małgorzata Franus

AbstractThis paper presents results of the studies of ciliate assemblage in benthos of lowland river influenced by sewage discharged from the municipal wastewater treatment plant. During the presented research the 47 ciliate species, including 45 species from the benthos of the river and 18 from the activated sludge of aeration chamber were identified. Only two species registered in the activated sludge were not observed in the river. Against the background of the lowest number of species in the point located in the distance of 50 m below the discharge of sewage the maximum amount and biomass of these species were observed. Whereas, 200 m below the discharge the decrease in number and biomass of ciliate to the level noted for location before the discharge was observed. Thus, generalizing, one may state that influence of municipal WWTP sewage discharge for ciliate assemblage in the river’s benthos was clearly visible but local.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 75-87 ◽  
Author(s):  
Y. J. Shao ◽  
J. Crosse ◽  
E. Keller ◽  
D. Jenkins

The City of Los Angeles USA Hyperion Treatment Plant (HTP) implemented high rate air activated sludge operations in November 1989. Using this process, the secondary treatment organic loading (F/M) was increased from 0.5 to 1.0 kg BOD/kg MLVSS/day and the MCRT reduced from 3.1 days to 1.5 days, thereby enabling the secondary treated flow to be increased from 150 mgd to 200mgd (6.6 to 8.8 m3/s). Excellent secondary effluent quality (BOD5 = 15 mg/l, carbonaceous BOD5 = 6 mg/l, SS = 6 mg/l) is currently obtained using rectangular secondary clarifiers operated at surface overflow rates of 1,100 gal/day/ft2 (43 m3/m2/day) and low MLSS concentrations (950 mg/l). The enhanced biological phosphorus removal that was obtained when operating at a 3 day MCRT was eliminated in the change to high rate operation and struvite (MgNH4PO4(c)) build-up in the anaerobic digesters has been eliminated. Nocardia scum formation, with its odor generating potential and other associated operating problems, has also been eliminated by high rate operation.


2011 ◽  
Vol 2011 ◽  
pp. 1-9
Author(s):  
S. A. Sadrnejad

A wastewater treatment plant is designed to daily treat 450000 m3 of wastewater collected from the city of Tehran. The wastewater treatment plant is located at the south of Shahr-Ray in southern Tehran with the area of 110 hectares. The treatment plant effluent will be transferred to Varamin agricultural lands to be used for the irrigation of crops. A conventional activated sludge for carbon removal and a high-rate trickling filter for nitrification of ammonia to nitrate are designed and constructed. The treatment plant consists of inlet pumping station, primary treatment, primary sedimentation tanks, selector and aeration tanks, trickling filter, and sludge treatment units. A mass balance analysis method which is a new approach for optimum design is used to achieve cost saving for the construction of south Tehran wastewater treatment plant. The comparison between combined system of activated sludge with trickling filter and an activated sludge alone shows that the combined system is 20% less costly and more efficient for the treatment of Tehran wastewater, the system has low volume demand, maximum biogas yeild, and low process control and is less variable to pH and chemical effects and highly energy-efficient.


2017 ◽  
Vol 9 (4) ◽  
pp. 413-418
Author(s):  
Aušra Mažeikienė ◽  
Julita Starenko

It is important to control not only the large wastewater treatment plants work, but also the work of individual small wastewater treatment plants for the protection of environment. Individual small wastewater treatment plants can become the local sources of pollution, when they are not functioning properly. Sewage purification indicators are not always the same as declared at wastewater treatment plants documentation in real conditions, so it is important to control the properly work of individual small wastewater treatment plants. The work of the small wastewater treatment plant AT-6 was analyzed by the treated sewage results (BDS7, SM, NH4-N, NO3-N, NO2-N, PO4-P), the quality of activated sludge, biological indicators and enzymatic activity in this article. The nitrification process was not going very well by the results of research, because there was the 72 mg/l concentration of ammonium nitrogen remaining in the cleaned wastewater. The morphological study of the activated sludge has confirmed the hypothesis that the necessary conditions for nitrification process were not established. The oxygen supply was increased and the small wastewater treatment plant functioning become more efficient, because nitrification process started working properly – there was less than 1 mg/l of ammonium nitrogen remaining in the cleaned wastewater.


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