Research Papers

Displaying 51 - 60 of 89
Almost 1/3 of household water samples that had been filtered by biosand or ceramic filters had nitrite levels higher than the WHO acute exposure guideline. Although filters decreased E. coli, they did not consistently provide low risk water.
In a study in Nicaragua, 77% of filters were still in use after 12 months. The filters removed 80% of E. coli, but there was recontamination in the storage buckets so the overall improvement was only 48%.
Rational design of domestic biosand filters; Kubare, M.; Haarhoff, J., 2010
The most important part of biosand filter design is the careful selection of appropriate filter media (i.e effective grain size, uniformity coefficient, porosity).
Microbial and chemical assessment of ceramic and BioSand water filters in rural Cambodia; Murphy, H.M.; Sampson, M.; Farahbakhsh, K.; McBean, E., 2010
In this study in Cambodia, the effluent of many ceramic and biosand filters had nitrite levels exceeding the WHO guideline levels for chronic exposure (a potential risk factor for blue baby syndrome).
Effect of production variables on microbiological removal in locally-produced ceramic filters for household water treatment.; Lantagne, D.; Klarman, M.; Mayer, A.; Preston, K.; Napotnik, J.; Jellison, K., 2010
The effectiveness of ceramic pot filters are effected by the clay:sawdust ratio and the type of "burnable" used. Whether the colloidal silver was painted on or burned in did not make a difference in this study.
The methodology used by Sobsey et al. (2008) to rank HWTS options was flawed. A "silver-bullet" approach is not appropriate, as complex local conditions must be accounted for.
Sobsey et al. defend their 2008 paper from criticism. Their evaluation was just a starting point based on available data, but all HWTS methods need more research.
There is enough evidence to state that ceramic filters are an effective form of HWT. There is not enough evidence for biosand filters, as more long term studies are required. The evidence suggests that SODIS, chlorination, and coagulation-chlorination are not effective in the long term.
E.coli samples analyzed with membrane filtration and m-coliBlue24 growth media had a coefficient of variation of 51%, with best results for colony counts of 15-150 per plate. Solarcult dipslides should not be used for present/absence testing.

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