scholarly journals Bacterial transmission and colonization in activated carbon block (ACB) point-of-use (PoU) filters

2021 ◽  
Author(s):  
Chia-Chen Wu ◽  
Nancy G. Love ◽  
Terese M. Olson
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Carbon Block ◽  
E Coli ◽  
Point Of Use ◽  
Bacterial Transmission

Identifying the breakthrough pattern of drinking water bacteria through faucet-mounted activated carbon block filters at the point of use using abiotic microspheres and biotic surrogates, fluorescent-tagged E. coli and P. aeruginosa.

scholarly journals The microbial colonization of activated carbon block point-of-use (PoU) filters with and without chlorinated phenol disinfection by-products

2017 ◽  
Vol 3 (5) ◽  
pp. 830-843 ◽  
Author(s):  
Chia-Chen Wu ◽  
Sudeshna Ghosh ◽  
Kelly J. Martin ◽  
Ameet J. Pinto ◽  
Vincent J. Denef ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Bacterial Community Structure ◽  
Microbial Colonization ◽  
Opportunistic Pathogens ◽  
Absolute Abundance ◽  
Carbon Block ◽  
Point Of Use ◽  
Water Filters ◽  
By Products

Activated carbon based point-of-use drinking water filters change the bacterial community structure and increase the absolute abundance of genera, including those associated with opportunistic pathogens.

Contamination of drinking water between source and point-of-use in rural households of South Africa and Zimbabwe: implications for monitoring the Millennium Development Goal for water

2006 ◽  
Vol 1 (2) ◽  
Author(s):  
Stephen W. Gundry ◽  
James A. Wright ◽  
Ronan Conroy ◽  
Martella Du Preez ◽  
Bettina Genthe ◽  
...  
Keyword(s):  
South Africa ◽  
Drinking Water ◽  
Millennium Development Goal ◽  
Significant Deterioration ◽  
Development Goal ◽  
E Coli ◽  
Safe Water ◽  
Point Of Use ◽  
Quality Of Water

Aims: To assess contamination of drinking water in rural Zimbabwe and South Africa Methods: We conducted a cohort study of 254 children aged 12-24 months in rural South Africa and Zimbabwe. In dry and wet seasons, we measured water quality, using the indicator organism E. coli, at improved and unimproved sources, in household storage and drinking cups. We also recorded hygiene and socio-economic factors for each household. Results: For improved sources, samples with E. coli counts less than 10 cfu/100ml were as follows: at source: 165 (88%); in household storage 137 (59%); in drinking cups 91 (49%). The corresponding values for unimproved sources were: source 47 (29%); household storage 32 (19%); drinking cups 21 (18%). This significant deterioration in microbial quality of water from improved sources was seen in both countries and both survey rounds. Conclusion: Although improved sources generally delivered ‘safe’ water at the point-of-supply, 12% of source samples were contaminated and as such were ‘unsafe’. Furthermore, in household storage, more than 40% of samples were ‘unsafe’. For monitoring the Millennium Development Goal for water, UNICEF-WHO are assuming an equivalence between ‘improved’ sources and ‘safe’ water. Our findings suggest that this equivalence may be unsound.

Efficacy of a ceramic siphon household water filter for removal of pathogenic microorganisms: lifespan volume test

2011 ◽  
Vol 1 (2) ◽  
pp. 102-111 ◽  
Author(s):  
Amanda R. Kaufman ◽  
Lisa M. Casanova ◽  
Mark D. Sobsey
Keyword(s):  
Drinking Water ◽  
Feed Water ◽  
Virus Removal ◽  
Water Filter ◽  
E Coli ◽  
Bacteriophage Ms2 ◽  
Point Of Use ◽  
Household Water ◽  
Contaminated Drinking Water ◽  
Pass Through

Treatment of drinking water at the point of use (POU) has demonstrated health benefits for people who have access only to microbially contaminated drinking water. In this work, the ceramic siphon POU water filter was evaluated for its ability to reduce indicator microorganisms in test waters. During batch challenge tests, the filter reduced Escherichia coli in filtered water by 7 log10 (99.999987%) and bacteriophage MS2 by 0.12 log10 (24.0%). Next, a novel continuous flow dosing system allowing sewage-amended feed water to constantly pass through the filters allowed for determination of changes in microbial reductions over time and total volume of water filtered. E. coli B, MS2 and fluorescent microspheres (as a surrogate for Cryptosporidium oocysts) were seeded into test water and dosed to filters at 10, 25 and 50% of the filter's volume lifespan. Microbial removal efficacy decreased as the volume of water filtered increased and test filters did not achieve their volume lifespan before physically failing. The ceramic siphon household water filter is effective in reducing E. coli and surrogates for Cryptosporidium in water, but filter modifications may be needed to achieve acceptable levels of virus removal and to reach the target 7,000 L volume lifespan of the filter.

scholarly journals The efficacy of chlorine-based disinfectants against planktonic and biofilm bacteria for decentralised point-of-use drinking water

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gillian E. Clayton ◽  
Robin M. S. Thorn ◽  
Darren M. Reynolds
Keyword(s):  
Antimicrobial Activity ◽  
Drinking Water ◽  
Hypochlorous Acid ◽  
Drinking Water Treatment ◽  
Distribution Networks ◽  
Free Chlorine ◽  
Biofilm Reactor ◽  
E Coli ◽  
Point Of Use ◽  
Biofilm Bacteria

AbstractChlorine solutions are used extensively for the production of biologically safe drinking water. The capability of point-of-use [POU] drinking water treatment systems has gained interest in locations where centralised treatment systems and distribution networks are not practical. This study investigated the antimicrobial and anti-biofilm activity of three chlorine-based disinfectants (hypochlorite ions [OCl-], hypochlorous acid [HOCl] and electrochemically activated solutions [ECAS]) for use in POU drinking water applications. The relative antimicrobial activity was compared within bactericidal suspension assays (BS EN 1040 and BS EN 1276) using Escherichia coli. The anti-biofilm activity was compared utilising established sessile Pseudomonas aeruginosa within a Centre for Disease Control [CDC] biofilm reactor. HOCl exhibited the greatest antimicrobial activity against planktonic E. coli at >50 mg L−1 free chlorine, in the presence of organic loading (bovine serum albumen). However, ECAS exhibited significantly greater anti-biofilm activity compared to OCl- and HOCl against P. aeruginosa biofilms at ≥50 mg L−1 free chlorine. Based on this evidence disinfectants where HOCl is the dominant chlorine species (HOCl and ECAS) would be appropriate alternative chlorine-based disinfectants for POU drinking water applications.

scholarly journals Field trial of an automated batch chlorinator system at shared water points in an urban community of Dhaka, Bangladesh

2016 ◽  
Vol 6 (1) ◽  
pp. 32-41 ◽  
Author(s):  
Nuhu Amin ◽  
Yoshika S. Crider ◽  
Leanne Unicomb ◽  
Kishor K. Das ◽  
Partha Sarathi Gope ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Low Income ◽  
Technology Development ◽  
User Preferences ◽  
Intermittent Flow ◽  
Small Scale ◽  
E Coli ◽  
Point Of Use ◽  
Colony Forming Units

Point-of-use water treatment with chlorine is underutilized in low-income households. The Zimba, an automated batch chlorinator, requires no electricity or moving parts, and can be installed at shared water points with intermittent flow. We conducted a small-scale trial to assess the acceptability and quality of Zimba-treated municipal water. Fieldworkers collected stored drinking water over a 10-week period from control (n = 24 households) and treatment (n = 30 households) compounds to assess levels of free chlorine and E. coli contamination. Overall, 80% of stored drinking water samples had a safe chlorine residual among treatment households, compared to 29% among control households (P < 0.001). Concentrations of E. coli were lower (mean difference = 0.4 log colony-forming units/100 mL, P = 0.004) in treatment compared to control households. Fifty-three percent of mothers (n = 17), thought the Zimba was easy to use and 76% were satisfied with the taste. The majority of mothers mentioned that collecting water from the Zimba took more time and created a long queue at the handpump. The Zimba successfully chlorinated household stored drinking water; however, further technology development is required to address user preferences. The Zimba may be a good option for point-of-collection water treatment in areas where queuing for water is uncommon.

Bacteriological quality of drinking water at point of use and hand hygiene of primary food preparers: implications for household food safety

2016 ◽  
Vol 6 (2) ◽  
pp. 224-230
Author(s):  
S. G. D. N. Lakshmi Reddi ◽  
R. Naveen Kumar ◽  
G. M. SubbaRao ◽  
M. Vishnu Vardhana Rao ◽  
R. V. Sudershan
Keyword(s):  
Drinking Water ◽  
Food Safety ◽  
Hand Hygiene ◽  
Low Income ◽  
Water Samples ◽  
Faecal Coliforms ◽  
E Coli ◽  
Point Of Use ◽  
Drinking Water Samples

Quality of water for consumption and food processing activities is universally accepted as an essential component to ensure food safety at household (HH) level. Along with safe water, hand hygiene is also an important factor for reducing diarrheal illnesses. This was a cross-sectional study conducted in rural and urban HHs to detect hygiene indicators in drinking water samples at point of use (PoU) (n = 150) and their association with the hand hygiene of primary food preparers (n = 150). Overall, 24.7% and 9.3% of drinking water samples (PoU), 48% and 20% of hand rinse samples were contaminated by faecal coliforms and E. coli, respectively. Both drinking water (PoU) and hand rinse samples collected from rural HHs showed higher contamination, followed by those from urban slums and low income HHs. Significant association (p < 0.05) and probable risk with faecal coliforms (OR. 2.5; 95% CI: 1.1–5.4) and E. coli (OR. 14.5; 95% CI: 4.1–50.7) was found between hand rinses and drinking water samples that had bacteriological contamination. These results suggest that there was an extensive cross contamination at HH level. So, targeted education is essential on safe food/water handling practices in HHs to prevent food safety risks.

scholarly journals Occurrence of Escherichia coli and faecal coliforms in drinking water at source and household point-of-use in Rohingya camps, Bangladesh

Gut Pathogens ◽  
2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Zahid Hayat Mahmud ◽  
Md Shafiqul Islam ◽  
Khan Mohammad Imran ◽  
Syed Adnan Ibna Hakim ◽  
Martin Worth ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Water Samples ◽  
Human Consumption ◽  
Risk Category ◽  
Human Beings ◽  
Faecal Coliforms ◽  
E Coli ◽  
Point Of Use ◽  
Quality Of Water

Abstract Background Safe water is essential for life but unsafe for human consumption if it is contaminated with pathogenic microorganisms. An acceptable quality of water supply (adequate, safe and accessible) must be ensured to all human beings for a healthy life. Methods We collected and analyzed a total of 12,650 drinking water samples, for the presence of Escherichia coli and faecal coliforms, from a large habitation of the displaced Rohingya population comprising of about 1.16 million people living within 4 km2. Results We found that 28% (n = 893) water samples derived from tubewells were contaminated with faecal coliforms and 10.5% (n = 333) were contaminated with E. coli; also, 73.96% (n = 4644) samples from stored household sources (at point of use—POU) were found contaminated with faecal coliforms while 34.7% (n = 2179) were contaminated with E. coli. It was observed that a higher percentage of POU samples fall in the highest risk category than that of their corresponding sources. Conclusions From our findings, it appears that secondary contamination could be a function of very high population density and could possibly occur during collection, transportation, and storage of water due to lack of knowledge of personal and domestic hygiene. Hence, awareness campaign is necessary, and the contaminated sources should be replaced. Further, the POU water should be treated by a suitable method.

scholarly journals Evaluation of Lead (Pb(II)) Removal Potential of Biochar in a Fixed-bed Continuous Flow Adsorption System

2020 ◽  
Vol 10 (28) ◽  
Author(s):  
Pushpita Kumkum ◽  
Sandeep Kumar
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Continuous Flow ◽  
Health Effect ◽  
Fixed Bed ◽  
Adsorption Potential ◽  
Adsorption System ◽  
Nelson Model ◽  
Point Of Use ◽  
Financial Interests

Background. Lead (Pb(II)) exposure from drinking water consumption is a serious concern due to its negative health effect on human physiology. A commercially available filter uses the adsorption potential of activated carbon for removing heavy metals like Pb(II). However, it has some constraints since it uses only surface area for the adsorption of these contaminants. Biochar produced via slow pyrolysis of biomass shows the presence of oxygen-containing functional groups on its surface that take part in the adsorption process, with higher removal potential compared to activated carbon. Objectives. The current study examined the adsorption kinetics and mechanisms of Pb(II) removing potential of biochar from water using a fixed-bed continuous flow adsorption system. Methods. The effect of initial Pb(II) concentration, mass of adsorbent (bed depth), and flow rate on adsorption potential were evaluated. The Adams-Bohart model, Thomas model, and Yoon-Nelson model were applied to the adsorption data. Results. The maximum removal efficiency of Pb(II) was 88.86 mg/g. The result illustrated that the Yoon-Nelson model is the best fit to analyze the adsorption phenomena of Pb(II) in a fixed-bed biochar column. Conclusions. The breakthrough data obtained from this study can be utilized to design a point of use filter that would be able to effectively remove Pb(II) from drinking water. Competing Interests. The authors declare no competing financial interests.

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