scholarly journals Optimising water treatment practices for the removal of Anabaena circinalis and its associated metabolites, geosmin and saxitoxins

2009 ◽  
Vol 7 (4) ◽  
pp. 544-556 ◽  
Author(s):  
Lionel Ho ◽  
Paul Tanis-Plant ◽  
Nawal Kayal ◽  
Najwa Slyman ◽  
Gayle Newcombe
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Practices ◽  
Water Treatment Plants ◽  
Cyanobacterium Anabaena ◽  
Pertinent Information ◽  
Equivalent Conditions ◽  
Anabaena Circinalis

The cyanobacterium Anabaena circinalis has the ability to co-produce geosmin and saxitoxins, compounds which can compromise the quality of drinking water. This study provides pertinent information in optimising water treatment practices for the removal of geosmin and saxitoxins. In particular, it demonstrates that pre-oxidation using potassium permanganate could be applied at the head of water treatment plants without releasing intracellular geosmin and saxitoxins from A. circinalis. Furthermore, powdered activated carbon (PAC) was shown to be an effective treatment barrier for the removal of extracellular (dissolved) geosmin and saxitoxins, with similar adsorption trends of both compounds. The relative removal of the saxitoxins compared with geosmin was determined to be 0.84±0.27, which implies that saxitoxin removal with PAC can be estimated to be approximately 60 to 100% of the removal of geosmin under equivalent conditions. Chlorine was shown to be effective for the oxidation of the saxitoxins with CT values of approximately 30 mg min l−1 required for greater than 90% destruction of the saxitoxins.

Occurrence of pathogenic microorganisms in the Saint Lawrence River (Canada) and comparison of health risks for populations using it as their source of drinking water

2000 ◽  
Vol 46 (6) ◽  
pp. 565-576 ◽  
Author(s):  
Pierre Payment ◽  
Aminata Berte ◽  
Michèle Prévost ◽  
Bruno Ménard ◽  
Benoît Barbeau
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Fecal Coliforms ◽  
Giardia Infection ◽  
Bacterial Indicators ◽  
Treatment Practices ◽  
Water Treatment Plants ◽  
Wide Range ◽  
Annual Risk

A 300-km portion of the Saint Lawrence hydrological basin in the province of Québec (Canada) and 45 water treatment plants were studied. River water used by drinking water treatment plants was analyzed (6-L sample volumes) to determine the level of occurrence of bacterial indicators (total coliforms, fecal coliforms, and Clostridium perfringens) and pathogens (Giardia lamblia, Cryptosporidium, human enteric viruses). Pathogens and bacterial indicators were found at all sites at a wide range of values. Logistic regression analysis revealed significant correlations between the bacterial indicators and the pathogens. Physicochemical and treatment practices data were collected from most water treatment plants and used to estimate the level of removal of pathogens achieved under cold (0°C-4°C) and warm (20°C-25°C) water temperature conditions. The calculated removal values were then used to estimate the annual risk of Giardia infection using mathematical models and to compare the sites. The estimated range of probability of infection ranged from 0.75 to less than 0.0001 for the populations exposed. Given the numerous assumptions made, the model probably overestimated the annual risk, but it provided comparative data of the efficacy of the water treatment plants and thereby contributes to the protection of public health.Key words: public health, drinking water, health risk, pathogen occurrence.

scholarly journals Long-Term Drinking Water Quality Assessment Using Index and Multivariate Statistical Analysis for Three Water Treatment Plants of Erbil City, Iraq

2018 ◽  
Vol 2 (2) ◽  
pp. 39-48
Author(s):  
Hayder Mohammed Issa ◽  
Reem Ahmed Alrwai
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Water Supply ◽  
Drinking Water Treatment ◽  
Drinking Water Quality ◽  
Total Alkalinity ◽  
Total Hardness ◽  
Water Treatment Plants

Safe source of drinking water is always considered as an essential factor in water supply for cities and urban areas. As a part of this issue, drinking water quality is monitored via a useful scheme: developing drinking water quality index DWQI. DWQI is preferably used as it summarizes the whole physicochemical and bacteriological properties of a drinking water sample into a single and simple term. In this study, an evaluation was made for three drinking water treatment plants DWTPs named: Efraz 1, Efraz 2 and Efraz 3 that supply drinking water to Erbil City. The assessment was made by testing thirteen physicochemical and two bacteriological parameters during a long period of (2003 – 2017). It has been found that turbidity, electrical conductivity EC, total alkalinity, total hardness, total coliform and fecal coliform have more influence on drinking water quality. DWQI results showed that the quality of drinking water supplied by the three DWTPs in Erbil City fallen within good level. Except various occasional periods where the quality was varying from good to fair. The quality of the drinking water supply never reached the level of marginal or poor over the time investigated. The applied hierarchical clustering analysis HCA classifies the drinking water dataset into three major clusters, reflecting diverse sources of the physicochemical and bacteriological parameter: natural, agriculture and urban discharges.

Reducing the chlorine dioxide demand in final disinfection of drinking water treatment plants using activated carbon

2015 ◽  
Vol 36 (12) ◽  
pp. 1499-1509 ◽  
Author(s):  
Sabrina Sorlini ◽  
Michela Biasibetti ◽  
Maria Cristina Collivignarelli ◽  
Barbara Marianna Crotti
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Chlorine Dioxide ◽  
Drinking Water Treatment ◽  
Water Treatment Plants

scholarly journals Simulation of a conventional water treatment plant for the minimization of new emerging pollutants in drinking water sources: process optimization using response surface methodology

RSC Advances ◽  
2017 ◽  
Vol 7 (19) ◽  
pp. 11550-11560 ◽  
Author(s):  
A. Vijaya Bhaskar Reddy ◽  
Zulkifli Yusop ◽  
Jafariah Jaafar ◽  
Azmi B. Aris ◽  
Zaiton A. Majid
Keyword(s):  
Response Surface Methodology ◽  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Response Surface ◽  
Process Optimization ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Emerging Pollutants ◽  
Water Treatment Plants

This study described the ability of conventional water treatment plants for the removal of NEPs by optimizing the concentrations of pH, PAC, activated carbon and chlorine (Cl2).

scholarly journals Heavy metals and arsenic in drinking water and health risk assessment of the region with the developed mining industry

2020 ◽  
Vol 99 (7) ◽  
pp. 725-732
Author(s):  
Gayane H. Babayan ◽  
Astghik G. Sakoyan
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Water Treatment ◽  
Water Supply ◽  
International Standards ◽  
Pollution Level ◽  
Water Supply Systems ◽  
Water Abstraction ◽  
Water Treatment Plants

Introduction. Drinking water intended for South Armenia’s towns and rural communities is abstracted from minor mountain rivers belonging to the basins of the Voghchi and Meghri, the water of which is treated at five water treatment plants. The river basins are home to the major copper molybdenum and gold ore mining centers of the republic.The purpose of this research was to study heavy metals Ag, Al, As, Cd, Cu, Fe, Mo, Ni, Pb, Sn, Sb, Se, Zn, Hg, Te in centralized drinking water supply systems and assess drinking water-caused health risks to the population.Material and methods. In 2016-2017 from 43 sampling sites a total of 53 basic water samples were taken, including 14- from surface water supply sources, 16 - from water treatment plants, 33- from water supply networks. Heavy metals were determined by the atomic absorption method. To assess the quality of water on water abstraction sites relevant ecological (regional) norms and national and international standards were used. The risk of development of noncarcinogenic and carcinogenic effects was assessed in the case of oral intake of and dermal exposure to tap water.Results. On water abstraction sites, background regional levels of surface waters exceeded the concentration of aluminum, iron, molybdenum, tin, antimony (by as 13.3-1.1 times). Water treatment efficiency at water treatment plants is estimated at 12% - 69% depending on different metals. Concentrations of heavy metals in drinking water do not exceed the norms. The risk of development of noncarcinogenic effects in the population at chronic exposure to drinking water is insignificant (HI<1), whereas a total carcinogenic risk exceeds a safety limit for arsenic (CR=9.59×10–5).Conclusion. The acceptable quality of drinking water supplied to consumers is not yet an index of sustainable and safe water supply in the studied region because of a water pollution level on intake sites, obsolete water treatment technologies, poor sanitation and technical condition of plants and water networks.

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