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.

Advanced wastewater disinfection technologies: short and long term efficiency

1998 ◽  
Vol 38 (12) ◽  
pp. 109-117 ◽  
Author(s):  
V. Lazarova ◽  
M. L. Janex ◽  
L. Fiksdal ◽  
C. Oberg ◽  
I. Barcina ◽  
...  
Keyword(s):  
Peracetic Acid ◽  
Contact Time ◽  
Pilot Scale ◽  
Coli Strain ◽  
Plate Count ◽  
Galactosidase Activity ◽  
Virus Removal ◽  
E Coli ◽  
Bacteriophage Ms2 ◽  
Short And Long Term

Advanced disinfection processes (peracetic acid, UV irradiation and ozonation) have been tested and evaluated through bench and pilot scale studies. 3 log removals of total coliforms, faecal coliforms and faecal streptococci were achieved by 10mg/L peracetic acid at a 10min contact time, by UV radiation at 35mW.s/cm2 and by ozone at 5mg/L for 10min contact time. Higher doses are required for virus removal by UV and PAA and especially for highly resistant viruses such as F-specific bacteriophage MS2. Ozonation has the advantage of having a strong effect on all types of bacteriophages and protozoa cysts even when low treatment doses and short contact times are applied. The results of this study demonstrated that evaluation of disinfection efficiency of ozone, UV and PAA depends on the criteria and methods employed. Standard method (plate count) results showed an important disinfection effect on culturability, while results from non-standard methods (respiratory activity and β-galactosidase activity assay) indicated less reduction of viable cells. Moreover, the results confirm that disinfectants act on bacteria in different ways. It has been clearly demonstrated that b-galactosidase activity is affected by PAA while UV treatment has no or very limited effect on the enzyme activity. Even without sunlight reactivation, bacterial regrowth in seawater was observed after disinfection of sewage effluents. This study also shows that the biodegradability of sewage effluent for an E coli strain was affected differently by the oxidative disinfectants ozone and PAA. Biodegradability should therefore be considered when evaluating the total disinfection efficiency.

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.

scholarly journals Gastroenteritis associated with accidental contamination of drinking water with partially treated water

2006 ◽  
Vol 135 (5) ◽  
pp. 818-826 ◽  
Author(s):  
T. M. A. FERNANDES ◽  
C. SCHOUT ◽  
A. M. De RODA HUSMAN ◽  
A. EILANDER ◽  
H. VENNEMA ◽  
...  
Keyword(s):  
Drinking Water ◽  
Human Error ◽  
Control Area ◽  
Adjacent Area ◽  
Housing Estate ◽  
Gastroenteritis Outbreak ◽  
Grey Water ◽  
Exposed Area ◽  
Household Water ◽  
Contaminated Drinking Water

SUMMARYDue to human error, drinking water supplied to a new housing estate in The Netherlands was contaminated with grey water. The cohort of 921 accidentally exposed households (area A) had a higher attack rate for diarrhoea (54·1%) than a non-exposed cohort of 1529 households from an adjacent area (B) (24%) (RR 2·3, 95% CI 1·9–2·7). Household water score showed a dose-response with illness, in both areas A and B. For each 1000 inhabitants, 19·8 cases in area A, 7·0 cases in control area B (RRAB2·2, 95% CI 1·3–3·8) and 3·3 cases in a more distant control area C (RRAC4·6, 95% CI 2·7–8·0) were diagnosed with gastroenteritis by their general practitioner. A gastroenteritis outbreak associated with consumption of contaminated drinking water was observed in the exposed area. The use of grey water was banned in 2003, with the exception of rainwater use for flushing toilets. The risk of rainwater use is currently being investigated.

Microbial counts and pesticide concentrations in drinking water after alum flocculation of channel feed water at the household level, in Vinh Long Province, Vietnam

2006 ◽  
Vol 5 (1) ◽  
pp. 171-178 ◽  
Author(s):  
Tim Wrigley
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
River Delta ◽  
World Health ◽  
Mekong River ◽  
Feed Water ◽  
Water Quality Criteria ◽  
Mekong River Delta ◽  
Household Level ◽  
E Coli

Low technology water supply, treatment and sanitation techniques were reviewed in a Vietnamese village in the Mekong River Delta as part of an AusAID Project to reduce poverty and to improve the overall living standards and health in the Cuu Long (Mekong) delta for 500,000 rural poor. It was found that dosing of canal water in 200-l ceramic jars with alum, PAC or PAC followed by hypochlorite provides a high level of treatment for drinking water at the household level in a rural village setting in the Mekong River delta. Seventy per cent (7 in total) of the 24 samples collected showed that Escherichia coli levels per 100 ml in the jars after treatment showed a ‘no risk’ profile (0 E. coli 100 ml-1) i.e. the water would be considered to be of very good quality for drinking according to World Health Organization Guidelines for Rural Drinking Water Supply. This included the eight samples that were dosed with hypochlorite. The remaining 30% of samples (seven in total) ranged from 14 to 47 E. coli 100 ml-1 which is considered an intermediate risk (10‒100 E. coli 100 ml-1) according to WHO guidelines. All control water samples (eight in total) were high or very high risk (>100 E. coli 100 ml-1). Pesticide concentrations generally were low and met Vietnamese drinking water quality criteria.

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.

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