Monitoring and evaluation of removal of pathogens at municipal wastewater treatment plants

2010 ◽  
Vol 61 (6) ◽  
pp. 1589-1599 ◽  
Author(s):  
C. Y. Fu ◽  
X. Xie ◽  
J. J. Huang ◽  
T. Zhang ◽  
Q. Y. Wu ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Primary Treatment ◽  
Fecal Coliforms ◽  
Municipal Wastewater Treatment ◽  
Tertiary Treatment ◽  
Somatic Coliphages ◽  
Untreated Wastewater ◽  
Municipal Wastewater Treatment Plants

The concentrations and removal of Cryptosporidium, Giardia, and microbial indicators, including somatic coliphages and fecal coliforms were investigated through the wastewater treatment processes at three municipal wastewater treatment plants in Beijing, China. The experimental results showed that the concentrations of Cryptosporidium in untreated wastewater, primary treatment effluent, secondary treatment effluent, tertiary treatment effluent were 33–600, 67–333, 0–9 and 0–0.4 oocysts L−1, and that of Giardia were 130–3,600, 533–2,033, 0–32 and 0–2.1 cysts L−1, respectively. The reduction ratios of Cryptosporidium and Giardia by the primary treatment process were 0.12 log and 0.18 log, respectively. Oxidation ditch process had higher reduction efficiency to Cryptosporidium and Giardia than anaerobic-anoxic-oxic process and conventional activated sludge process, probably because of longer retention time and higher sludge concentration. Membrane ultrafiltration had a notably better efficiency to reduce microorganisms, especially Cryptosporidium and Giardia, than conventional flocculation sedimentation and sand filtration process, as the tertiary treatment. Comparing with total coliforms, fecal coliforms and heterotrophic bacteria, concentration of somatic coliphages was correlated better with that of Cryptosporidium and Giardia in untreated wastewater and secondary treatment effluent.

Identification of pathogen bacteria and protozoa in treated urban wastewaters discharged in the Ebro River (Spain): water reuse possibilities

2013 ◽  
Vol 68 (3) ◽  
pp. 575-583 ◽  
Author(s):  
R. Mosteo ◽  
M. P. Ormad ◽  
P. Goñi ◽  
J. Rodríguez-Chueca ◽  
A. García ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Water Reuse ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Research Work ◽  
Municipal Wastewater Treatment ◽  
Tertiary Treatment ◽  
Salmonella Spp ◽  
Free Living ◽  
Municipal Wastewater Treatment Plants

The aim of this research work is to identify the presence of pathogens, bacteria and protozoa, in different treated urban wastewaters and to relate biological pollution with the processes used in wastewater treatment plants. A study of the possibilities for water reuse is carried out taking into account bacterial and parasite composition. The analysed bacteria and protozoa are: Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, Clostridium perfringens (spore), Salmonella spp., Legionella spp., helminths eggs, Giardia, Cryptosporidium spp. and free-living amoebae (FLA). The selected municipal wastewater treatment plants (MWTPs) are located in Navarra (Spain) and the main difference between them is the use of natural lagoons as tertiary treatment in some plants. The results concerning bacteriological identification showed contamination of mainly faecal origin, and the use of natural lagoons as tertiary treatment in some MWTPs produced an important disinfection effect. Moreover, pathogen parasites such as Giardia and Cryptosporidium were not detected in the samples studied although FLA were identified in all cases.

Microsieving in primary treatment: effect of chemical dosing

2016 ◽  
Vol 74 (2) ◽  
pp. 438-447 ◽  
Author(s):  
J. Väänänen ◽  
M. Cimbritz ◽  
J. la Cour Jansen
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Primary Treatment ◽  
Municipal Wastewater Treatment ◽  
Chemically Enhanced Primary Treatment ◽  
Municipal Wastewater Treatment Plants

Primary and chemically enhanced primary wastewater treatment with microsieving (disc or drum filtration) was studied at the large pilot scale at seven municipal wastewater treatment plants in Europe. Without chemical dosing, the reduction of suspended solids (SS) was (on average) 50% (20–65%). By introducing chemically enhanced primary treatment and dosing with cationic polymer only, SS removal could be controlled and increased to >80%. A maximum SS removal of >90% was achieved with a chemical dosing of >0.007 mg polymer/mg influent SS and 20 mg Al3+/L or 30 mg Fe3+/L. When comparing sieve pore sizes of 30–40 μm with 100 μm, the effluent SS was comparable, indicating that the larger sieve pore size could be used due to the higher loading capacity for the solids. Phosphorus removal was adjusted with the coagulant dose, and a removal of 95–97% was achieved. Moreover, microsieving offers favourable conditions for automated dosing control due to the low retention time in the filter.

The use of dissolved air flotation in municipal wastewater treatment

2001 ◽  
Vol 43 (8) ◽  
pp. 75-81 ◽  
Author(s):  
H. Ødegaard
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Primary Treatment ◽  
Chemical Plants ◽  
Municipal Wastewater Treatment ◽  
Dissolved Air Flotation ◽  
Biofilm Reactors ◽  
Municipal Wastewater Treatment Plants ◽  
Dissolved Air

Flotation can be used in municipal wastewater treatment plants in different ways. Since the pollutants in wastewater to such a large extent are associated with particles, a very substantial treatment efficiency can be reached at a very small space, by using flotation in a chemical (or enhanced primary) treatment scheme. This is demonstrated in this paper with reference to results from small, prefabricated chemical plants based on flotation, which are frequently used in Norway. If used in connection with biological plants (for instance for nitrogen removal), the combination of biofilm reactors and flotation is especially advantageous because coagulation/flocculation/flotation can be placed directly after the bioreactor. Results from two such plants in Norway are presented. Recommendations with respect to design and operation of flotation plants in wastewater treatment are given.

scholarly journals Microbial reduction in wastewater treatment using Fe3+ and Al3+ coagulants and PAA disinfectant

2013 ◽  
Vol 11 (4) ◽  
pp. 581-589 ◽  
Author(s):  
Surendra K. Pradhan ◽  
Ari Kauppinen ◽  
Kati Martikainen ◽  
Tarja Pitkänen ◽  
Jaana Kusnetsov ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Microbial Reduction ◽  
Pcr Analysis ◽  
Pathogenic Microorganisms ◽  
Municipal Wastewater Treatment ◽  
Tertiary Treatment ◽  
Municipal Wastewater Treatment Plants ◽  
Norovirus Gii

Wastewater is an important source of pathogenic enteric microorganisms in surface water and a major contaminating agent of drinking water. Although primary and secondary wastewater treatments reduce the numbers of microorganisms in wastewater, significant numbers of microbes can still be present in the effluent. The aim of this study was to test the feasibility of tertiary treatment for municipal wastewater treatment plants (WWTPs) using PIX (FeCl3) or PAX (AlCl3) coagulants and peracetic acid (PAA) the disinfectant to reduce microbial load in effluent. Our study showed that both PIX and PAX efficiently reduced microbial numbers. PAA disinfection greatly reduced the numbers of culturable indicator microorganisms (Escherichia coli, intestinal enterococci, F-specific RNA coliphages and somatic DNA coliphages). In addition, pathogenic microorganisms, thermotolerant Campylobacter, Salmonella and norovirus GI, were successfully reduced using the tertiary treatments. In contrast, clostridia, Legionella, rotavirus, norovirus GII and adenovirus showed better resistance against PAA compared to the other microorganisms. However, interpretation of polymerase chain reaction (PCR) analysis results will need further studies to clarify the infectivity of the pathogenic microbes. In conclusion, PIX and PAX flocculants followed by PAA disinfectant can be used as a tertiary treatment for municipal WWTP effluents to reduce the numbers of indicator and pathogenic microorganisms.

A study about the use of chemicals in conventional tertiary treatment. Performances comparison of three municipal wastewater treatment plants and pilot plant experiences

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
A. Iborra-Clar ◽  
J.A. Mendoza-Roca ◽  
A. Bes-Pií ◽  
J.J. Morenilla-Martínez ◽  
I. Bernácer-Bonora ◽  
...  
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Pilot Plant ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Secondary Effluent ◽  
Municipal Wastewater Treatment ◽  
Wastewater Reclamation ◽  
Valencian Region ◽  
Municipal Wastewater Treatment Plants

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.

Nanofiltration of endocrine disrupting compounds

2003 ◽  
Vol 3 (5-6) ◽  
pp. 321-327 ◽  
Author(s):  
M. Gallenkemper ◽  
T. Wintgens ◽  
T. Melin
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Endocrine Disrupting Compounds ◽  
Municipal Wastewater Treatment ◽  
Water And Wastewater Treatment ◽  
Wide Range ◽  
Endocrine Disrupting ◽  
Municipal Wastewater Treatment Plants ◽  
Set Up

Endocrine disrupting compounds can affect the hormone system in organisms. A wide range of endocrine disrupters were found in sewage and effluents of municipal wastewater treatment plants. Toxicological evaluations indicate that conventional wastewater treatment plants are not able to remove these substances sufficiently before disposing effluent into the environment. Membrane technology, which is proving to be an effective barrier to these substances, is the subject of this research. Nanofiltration provides high quality permeates in water and wastewater treatment. Eleven different nanofiltration membranes were tested in the laboratory set-up. The observed retention for nonylphenol (NP) and bisphenol A (BPA) ranged between 70% and 100%. The contact angle is an indicator for the hydrophobicity of a membrane, whose influence on the permeability and retention of NP was evident. The retention of BPA was found to be inversely proportional to the membrane permeability.

Experience from 10 Years Advanced Wastewater Treatment – Technology and Results

1982 ◽  
Vol 14 (1-2) ◽  
pp. 121-133
Author(s):  
C Forsberg ◽  
B Hawerman ◽  
B Hultman
Keyword(s):  
Wastewater Treatment ◽  
Urban Population ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Municipal Wastewater Treatment ◽  
Treatment Technology ◽  
Removal Efficiencies ◽  
Municipal Wastewater Treatment Plants ◽  
Operational Modes ◽  
Polluted Waters

Experience from advanced municipal wastewater treatment plants and recovery of polluted waters are described for the last ten years in Sweden. Except in municipalities with large recipients, the urban population is served by treatment plants with combined biological and chemical treatment. Most of these plants are post-precipitation plants. Several modified operational modes have been developed in order to improve the removal efficiencies of pollutants and to reduce the costs. Results are presented on the recovery of specially investigated lakes with a lowered supply of total phosphorus and organic matter.

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