Detection and Health Risk Associated with Low Virus Concentration in Drinking Water

1985 ◽  
Vol 17 (10) ◽  
pp. 97-103 ◽  
Author(s):  
P. Payment ◽  
M. Trudel
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Health Problem ◽  
Conventional Treatment ◽  
Probabilistic Approach ◽  
Detection Methods ◽  
Virus Concentration ◽  
The Subject ◽  
Treated Drinking Water ◽  
Dangerous Level

During the last decade, with the amelioration of the detection methods and the increasing number of studies on the subject, the isolation of viruses in treated drinking water has been reported more frequently than ever. These reports have in common the very low number of viruses isolated and these viruses are usually found only after concentration procedures involving several hundred liters of water. Our own studies have shown that during the conventional treatment of drinking water 99.998% of the indigenous viruses are removed. The residual viral fraction does not exceed 10 viruses per 1 000 liters of water. Using a probabilistic approach this viral concentration in drinking water is well below any dangerous level of enteric viruses in water and the presence of these viruses should not be considered as a health problem but more as the limit of the water treatment methodology.

scholarly journals Cyanobacteria and microcystin contamination in untreated and treated drinking water in Ghana

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Gloria Naa Dzama Addico ◽  
Jörg D. Hardege ◽  
Jiri Kohoutek ◽  
Kweku Amoaku Atta DeGraft-Johnson ◽  
Pavel Babica
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Human Health ◽  
Metropolitan Area ◽  
Cyanobacterial Blooms ◽  
Maximal Concentration ◽  
Raw Water ◽  
Treated Water ◽  
Treated Drinking Water ◽  
Who Guideline

<p>Although cyanobacterial blooms and cyanotoxins represent a worldwide-occurring phenomenon, there are large differences among different countries in cyanotoxin-related human health risk assessment, management practices and policies. While national standards, guideline values and detailed regulatory frameworks for effective management of cyanotoxin risks have been implemented in many industrialized countries, the extent of cyanobacteria occurrence and cyanotoxin contamination in certain geographical regions is under-reported and not very well understood. Such regions include major parts of tropical West and Central Africa, a region constisting of more than 25 countries occupying an area of 12 million km<sup>2</sup>, with a total population of 500 milion people. Only few studies focusing on cyanotoxin occurrence in this region have been published so far, and reports dealing specifically with cyanotoxin contamination in drinking water are extremely scarce. In this study, we report seasonal data on cyanobacteria and microcystin (MC) contamination in drinking water reservoirs and adjacent treatment plants located in Ghana, West Africa. During January-June 2005, concentrations of MCs were monitored in four treatment plants supplying drinking water to major metropolitan areas in Ghana: the treatment plants Barekese and Owabi, which serve Kumasi Metropolitan Area, and the plants Kpong and Weija, providing water for Accra-Tema Metropolitan Area. HPLC analyses showed that 65% samples of raw water at the intake of the treatment plants contained intracellular MCs (maximal detected concentration was 8.73 µg L<sup>-1</sup>), whereas dissolved toxins were detected in 33% of the samples. Significant reduction of cyanobacterial cell counts and MC concentrations was achieved during the entire monitoring period by the applied conventional water treatment methods (alum flocculation, sedimentation, rapid sand filtration and chlorination), and MC concentration in the final treated water never exceeded 1 µg L<sup>-1</sup> (WHO guideline limit for MCs in drinking water). However, cyanobacterial cells (93-3,055 cell mL<sup>-1</sup>) were frequently found in the final treated water and intracellular MCs were detected in 17% of the samples (maximal concentration 0.61 µg L<sup>-1</sup>), while dissolved MCs were present in 14% of the final treated water samples (maximal concentration 0.81 µg L<sup>-1</sup>). It indicates a borderline efficiency of the water treatment, thus MC concentrations in drinking water might exceed the WHO guideline limit if the treatment efficiency gets compromised. In addition, MC concentrations found in the raw water intake might represent significant human health risks for people living in areas with only a limited access to the treated or underground drinking water.</p>

Occurrence of microcystins in raw water sources and treated drinking water of Finnish waterworks

2001 ◽  
Vol 43 (12) ◽  
pp. 225-228 ◽  
Author(s):  
K. Lahti ◽  
J. Rapala ◽  
A-L. Kivimäki ◽  
J. Kukkonen ◽  
M. Niemelä ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Water Sources ◽  
World Health ◽  
Bank Filtration ◽  
Raw Water ◽  
Guide Value ◽  
The World ◽  
Treated Drinking Water

Problems caused by cyanobacteria are common around the world and also in raw water sources of drinking water treatment plants. Strains belonging to genera Microcystis, Anabaena and Planktothrix produce potent hepatotoxins, the microcystins. Laboratory and pilot scale studies have shown that microcystins dissolved in water may pass the conventional surface water treatment processes. In 1998 the World Health Organization proposed a guide value of 1 μg/L for microcystin-LR (MC-LR) in drinking water. The purpose of this research was to study the occurrence of microcystins in raw water sources of surface waterworks and in bank filtration plants and to evaluate the removal of microcystins in operating waterworks. Four bank filtration plants and nine surface waterworks using different processes for water treatment were monitored. Phytoplankton was identified and quantified, and microcystins analysed with sensitive immunoassay. Microcystin occurrence in selected water samples was verified with HPLC and a protein phosphatase inhibition method. Microcystins were detected sporadically in raw water sources of most of the waterworks. In two raw water supplies toxins were detected for several months. The highest microcystin concentrations in incoming raw water were approximately 10 μg/L MC-LR equivalents. In treated drinking water microcystins were detected occasionally but the concentrations were always below the guide value proposed by WHO.

scholarly journals Effect of increasing bromide concentration on toxicity in treated drinking water

2015 ◽  
Vol 14 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Emma Sawade ◽  
Rolando Fabris ◽  
Andrew Humpage ◽  
Mary Drikas
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Distribution Systems ◽  
Water Quality Management ◽  
Drinking Water Treatment ◽  
Sudden Onset ◽  
Toxic Species ◽  
Treated Drinking Water ◽  
The Impact

Research is increasingly indicating the potential chronic health effects of brominated disinfection by-products (DBPs). This is likely to increase with elevated bromide concentrations resulting from the impacts of climate change, projected to include extended periods of drought and the sudden onset of water quality changes. This will demand more rigorous monitoring throughout distribution systems and improved water quality management at water treatment plants (WTPs). In this work the impact of increased bromide concentration on formation of DBPs following conventional treatment and chlorination was assessed for two water sources. Bioanalytical tests were utilised to determine cytotoxicity of the water post disinfection. Coagulation was shown to significantly reduce the cytotoxicity of the water, indicating that removal of natural organic matter DBP precursors continues to be an important factor in drinking water treatment. Most toxic species appear to form within the first half hour following disinfectant addition. Increasing bromide concentration across the two waters was shown to increase the formation of trihalomethanes and shifted the haloacetic acid species distribution from chlorinated to those with greater bromine substitution. This correlated with increasing cytotoxicity. This work demonstrates the challenges faced by WTPs and the possible effects increasing levels of bromide in source waters could have on public health.

Evaluation of Student Handwashing Practices During a School-Based Hygiene Program in Rural Western Kenya, 2007

2017 ◽  
Vol 37 (2) ◽  
pp. 121-128 ◽  
Author(s):  
Genevieve La Con ◽  
Katharine Schilling ◽  
Julie Harris ◽  
Bobbie Person ◽  
Mercy Owuor ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Focus Groups ◽  
Primary Schools ◽  
Respiratory Infections ◽  
Educational Materials ◽  
Western Kenya ◽  
School Based ◽  
Teachers Attitudes ◽  
Treated Drinking Water

Unsafe drinking water and inadequate handwashing facilities in primary schools increase the risk of absenteeism due to diarrhea and respiratory infections. To mitigate these risks, we provided 28 schools in rural Western Kenya with handwashing and drinking water stations (containers with lids and taps on metal stands), bleach for water treatment, soap for handwashing, and educational materials. We observed the use of the water stations and assessed teachers’ attitudes toward the intervention. Of 151 total handwashing stations, 69 (59%) were observed to have soap and water and treated drinking water 4 months after implementation; observations of pupils showed an increase in handwashing behavior in water stations located < 10 m, as compared with those >10 m, from latrines ( p < .02). In focus groups, teachers reported improved cleanliness and decreased illness in pupils. Teacher training and installation of water stations resulted in observed improvements in pupils’ hygiene, particularly when water stations were located <10 m from latrines.

Enhancing climate adaptation capacity for drinking water treatment facilities

2016 ◽  
Vol 7 (3) ◽  
pp. 485-497 ◽  
Author(s):  
Audrey D. Levine ◽  
Y. Jeffrey Yang ◽  
James A. Goodrich
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Conventional Treatment ◽  
Distribution Systems ◽  
Climate Adaptation ◽  
Extreme Temperature ◽  
Water Sources ◽  
Modeling Framework ◽  
Adaptation Capacity

Conventional water treatment processes (e.g., coagulation, flocculation, sedimentation, and filtration) are widely used for producing drinking water from surface water sources. Transient, gradual, or abrupt changes in source water quality that could compromise treatment effectiveness can be triggered by climate and related meteorological events, accidental or intentional contamination, security breaches, or other disruptions. However, the design principles that underpin the majority of existing conventional treatment systems predate climate adaptation considerations. This paper considers the adaptation capacity of conventional water treatment systems. A modeling framework is used to illustrate climate adaptation mechanisms that could enable conventional treatment systems to accommodate water quality impairments. Treatment system resiliency is explored in response to generic climate-relevant water quality perturbations such as extreme temperature variations and changes in the quantity and characteristics of solids, particles, and organic constituents. Promising adaptation options include modifying chemical parameters (e.g., types of chemicals, dosages, sequence of chemical addition, mixing intensity and duration), filter operations, and microbiological augmentation of existing physical/chemical treatment systems. The capacity reserve concept provides an organizing principle that could be useful for prioritizing climate adaptation strategies such as major or minor treatment/infrastructure modifications, system-wide upgrades such as off-line storage, operational changes in distribution systems, or the use of supplemental water sources including reclaimed or recycled water.

Phosphorus in Drinking Water and it's Removal in Conventional Treatment Process

2012 ◽  
Vol 461 ◽  
pp. 453-456 ◽  
Author(s):  
Deng Ling Jiang ◽  
Yan Hua Chen ◽  
Guo Wei Ni
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Conventional Treatment ◽  
Treatment Process ◽  
Particulate Phosphorus ◽  
Available Phosphorus ◽  
Water Removal ◽  
Soluble Phosphate ◽  
Source Water ◽  
Treated Drinking Water

Chemical forms of phosphorus in source and treated drinking water were studied in this paper. Removal of total phosphorus (TP) and microbially available phosphorus (MAP) by conventional treatment process of drinking water was examined. The results showed that particulate phosphorus constituted of most TP in source water. Content of total soluble phosphate (TSP) was about 30% of TP. Soluble reactive phosphate (SRP) can be measured in a few months during a year and its content was very low. Content of MAP was higher than content of TSP in source water, which showed that microbe can also use particle phosphorus. Ratio of TSP to TP increased evidently in treated water. This demonstrated that removal of TSP was more difficult than particulate phosphorus in conventional treatment process for drinking water. Removal of TP and MAP in conventional treatment process of drinking water was effective, with averaged removal efficiency of 66% and 69%, respectively. Coagulation-sedimentation and filtration removed TP efficiently. Enhanced coagulation may increases removal efficiency of MAP. Lower content of MAP can control biostability of drinking water.

Properties of mortar incorporating untreated and treated drinking water treatment sludge

2021 ◽  
Vol 280 ◽  
pp. 122558
Author(s):  
Phuong Ngoc Pham ◽  
Weiwei Duan ◽  
Yan Zhuge ◽  
Yue Liu ◽  
Ismael Esteban Serna Tormo
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Water Treatment Sludge ◽  
Treated Drinking Water

scholarly journals A matter of good taste: investigating preferences for in-house water treatment in peri-urban communities in Cambodia

2015 ◽  
Vol 21 (3) ◽  
pp. 291-317 ◽  
Author(s):  
Marc Jeuland ◽  
Jennifer Orgill ◽  
Ameer Shaheed ◽  
Geoff Revell ◽  
Joe Brown
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Urban Communities ◽  
Quality Improvements ◽  
Water Safety ◽  
Phnom Penh ◽  
Household Water Treatment ◽  
Treatment Methods ◽  
Double Blinded ◽  
Treated Drinking Water

AbstractLow demand for safe water may partly result from a perceived distaste towards or the inconvenience of treatment methods. This paper analyzes preferences for water quality improvements in peri-urban Phnom Penh. The authors first analyze data from a discrete choice experiment in which respondents selected their preferred alternative from generic options varying in cost, taste acceptability, effectiveness against diarrhea and quantity of water treated. The choice patterns suggest that demand for water treatment is highly dependent on taste acceptability. The authors also use double-blinded taste tests to show that respondents are sensitive to one common taste in treated drinking water, that stemming from chlorine disinfection. While many compounds (natural and anthropogenic) may contribute to taste problems in drinking water, the lack of alignment between household preferences for taste and water safety may play a role in the low use of household water treatment methods in many settings.

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