Removal of Noro- and Enteroviruses, Giardia Cysts, Cryptosporidium Oocysts, and Fecal Indicators at Four Secondary Wastewater Treatment Plants in Sweden

The aim of this study was to assess the impact of a municipal wastewater treatment plant (MWTP) on the occurrence of Cryptosporidium oocysts and Giardia cysts in the receiving water. All MWTP effluent samples were Giardia and Cryptosporidium contaminated, although low mean values were found for both parasites (0.21±0.06 oocysts/L; 1.39±0.51 cysts/L). Otherwise, in the raw sewage a greater concentration was detected (4.5±0.3 oocysts/L; 53.6±6.8 cysts/L). The major occurrence of Giardia over Cryptosporidium, both in the influent and in the effluent of the MWTP, is probably related to the human sewage contribution to the wastewater. Data on protozoa contamination of the receiving water body demonstrated similar concentrations in the samples collected before (0.21±0.07 oocysts/L; 1.31±0.38 cysts/L) and after (0.17±0.09 oocysts/L and 1.01±1.05 cysts/L) the plant effluent discharge. The results of this study suggest that the MWTP has no impact related to Giardia and Cryptosporidium river water contamination, and underline the need for investigation into the effectiveness of these protozoa removal by less technologically advanced MWTPs which are the most widespread and could probably show a lower ability to reduce protozoa.

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Occurrence and persistence of bacterial and viral faecal indicators in wastewater biofilms

Water Science & Technology ◽

10.2166/wst.2007.280 ◽

2007 ◽

Vol 55 (8-9) ◽

pp. 377-385 ◽

Cited By ~ 13

Author(s):

S. Skraber ◽

K. Helmi ◽

R. Willame ◽

M. Ferréol ◽

C. Gantzer ◽

...

Keyword(s):

Dynamic Equilibrium ◽

Wastewater Treatment Plants ◽

Plate Count ◽

Cryptosporidium Oocysts ◽

The Matrix ◽

Thermotolerant Coliforms ◽

Viral Indicators ◽

The Stability ◽

Faecal Indicators ◽

Giardia Cysts

Biofilms within wastewater treatment plants can capture enteric microorganisms initially present in the water phase immobilising them either definitively or temporarily. Consequently, fates of microorganisms may totally change depending on whether they interact or not with biofilms. In this study, we assessed the stability of wastewater biofilms comparing the evolution of the concentrations of bacteria (heterotrophic plate count [HPC], thermotolerant coliforms [TC]) and viral (somatic coliphages [SC] and F-specific phages [F+]) indicators in the biofilms and in the corresponding wastewaters at 4 and 20 °C. Additionally, we assessed the monthly occurrence of these bacterial and viral indicators as well as of pathogenic protozoa (Cryptosporidium oocysts and Giardia cysts) in three native wastewater biofilms for four months. Our results show that viral indicators (SC and F+) persist longer in biofilms than in the corresponding wastewaters at 4 °C as well as at 20 °C. In contrast, persistence of bacterial indicators (TC and HPC) depends on both the temperature and the matrix. Differences between viral and bacterial persistence are discussed. Monthly analysis of native wastewater biofilms shows that bacterial and viral indicators, as well as Cryptosporidium oocysts and Giardia cysts, attach to wastewater biofilms to a concentration that remains stable in time, probably as a result of a dynamic equilibrium between attachment and detachment processes.

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Effects of sonication on bacteria viability in wastewater treatment plants evaluated by flow cytometry—Fecal indicators, wastewater and activated sludge

Water Research ◽

10.1016/j.watres.2006.08.021 ◽

2007 ◽

Vol 41 (1) ◽

pp. 235-243 ◽

Cited By ~ 88

Author(s):

Paola Foladori ◽

Bruni Laura ◽

Andreottola Gianni ◽

Ziglio Giuliano

Keyword(s):

Flow Cytometry ◽

Wastewater Treatment ◽

Activated Sludge ◽

Wastewater Treatment Plants ◽

Fecal Indicators

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Distribution of Giardia Cysts in Wastewater

Water Science & Technology ◽

10.2166/wst.1991.0055 ◽

1991 ◽

Vol 24 (2) ◽

pp. 187-192 ◽

Cited By ~ 31

Author(s):

Jan L. Sykora ◽

Charles A. Sorber ◽

Walter Jakubowski ◽

Leonard W. Casson ◽

Patrick D. Gavaghan ◽

...

Keyword(s):

Wastewater Treatment ◽

Wastewater Treatment Plants ◽

Geometric Mean ◽

Sewage Treatment ◽

Treatment Plant ◽

Late Summer ◽

The United States ◽

Giardia Cyst ◽

Direct Counts ◽

Giardia Cysts

This study was designed to determine geographic and seasonal distribution of Giardia cysts in wastewater and sludge and their removal by sewage treatment processes. Eleven wastewater treatment plants located in cities across the United States were included in the study. Flow weighted, composite samples of raw and treated wasteWaters and sludges were collected at monthly intervals for a period of one year. The cysts were concentrated by sucrose flotation or by simple centrifugation (“direct count”) and assayed microscopically. Sucrose flotation counts of cysts in the raw sewage were extremely variable producing results ranging from 0.4% to 77.8% of the direct counts. Based on 12 consecutive months of sampling, and using the direct counts, the highest geometric mean Giardia cyst concentrations occurred at the California site (3375 cysts/L), the Florida site (3087 cysts/L) and the Vermont site (2040 cysts/L). The lowest geometric mean Giardia cyst levels were in samples from the Pennsylvania site (642 cysts/L), the Tennessee site (762 cysts/L) and the Maryland site (957 cysts/L). Cyst concentrations in raw sewage were highest in late summer, fall and early winter. Although all raw sewage samples contained cysts, only about one half of the wastewater treatment plant effluents were positive with cyst concentrations ranging up to 44 cysts/L. Based on sucrose flotation counts, the concentrations of cysts detected in the sludges ranged from 70 to 30,000 cysts/L.

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Determining potential indicators of Cryptosporidium oocysts throughout the wastewater treatment process

Water Science & Technology ◽

10.2166/wst.2012.918 ◽

2012 ◽

Vol 65 (5) ◽

pp. 875-882 ◽

Cited By ~ 9

Author(s):

H.-W. A. Cheng ◽

M. A. Broaders ◽

F. E. Lucy ◽

S. E. Mastitsky ◽

T. K. Graczyk

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Municipal Wastewater ◽

Treatment Process ◽

Giardia Duodenalis ◽

Strong Positive Correlation ◽

Indicator Organisms ◽

Microbial Indicators ◽

Cryptosporidium Oocysts ◽

Giardia Cysts

Most research on wastewater treatment efficiency compliance focuses on physicochemical and microbial indicators; however, very little emphasis has been placed so far on determining suitable indicator organisms to predict the discharge level of pathogens from treatment plants. In this study, raw wastewater, activated sludge, and the resulting final effluents and biosolids in four municipal wastewater treatment plants (WWTPs A, B, C and D) were seasonally investigated for human-virulent water-borne pathogens Cryptosporidium parvum/hominis and Giardia duodenalis, and microsporidia (e.g. Encephalitozoon hellem, E. intestinalis, and Enterocytozoon bieneusi) between 2008 and 2009. A suite of potential microbial indicators for human-virulent protozoa and microsporidia was also determined. A combination of multiple fluorescent in situ hybridization and immunofluorescent antibody assays were applied to detect Cryptosporidium oocysts, Giardia cysts, and microsporidian spores. Escherichia coli, enterococci and Clostridium perfringens spores were cultivated in selective media. Positive correlations were found between the abundance of enterococci and E. coli and abundance of Cryptosporidium oocysts (rs > 0.47, p < 0.01) and Giardia cysts (rs > 0.44, p < 0.01) at WWTPs A–D. Cryptosporidium perfringens spores were positively correlated to Cryptosporidium oocysts (rs = 0.40, p < 0.01) and Giardia cysts (rs = 0.46, p < 0.01). There was a strong positive correlation between abundance of Giardia cysts and that of Cryptosporidium oocysts (rs > 0.89, p < 0.01). To sum up, a suite of faecal indicator bacteria can be used as indicators for the presence of Cryptosporidium oocysts and Giardia cysts in these activated-sludge systems (WWTPs A, B and C). Overall, Giardia duodenalis was noted to be the best Cryptosporidium indicator for human health in the community-based influent wastewater and throughout the treatment process.

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Prevalence and fate of giardia cysts in wastewater treatment plants

Journal of Applied Microbiology ◽

10.1111/j.1365-2672.2012.05335.x ◽

2012 ◽

Vol 113 (3) ◽

pp. 477-484 ◽

Cited By ~ 26

Author(s):

A.M. Nasser ◽

D. Vaizel-Ohayon ◽

A. Aharoni ◽

M. Revhun

Keyword(s):

Wastewater Treatment ◽

Wastewater Treatment Plants ◽

Giardia Cysts

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Analysis and balance of phosphorous removal from wastewater at urban wastewater treatment plant

Pollack Periodica ◽

10.1556/606.2020.15.2.13 ◽

2020 ◽

Vol 15 (2) ◽

pp. 142-151

Author(s):

Peter Lukac ◽

Lubos Jurik

Keyword(s):

Wastewater Treatment ◽

Wastewater Treatment Plant ◽

Wastewater Treatment Plants ◽

Sewage Treatment ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Phosphorus Recovery ◽

Anaerobic Sludge ◽

Biological Phosphorus Removal ◽

The Mean

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.

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