Research Papers

Displaying 51 - 60 of 89
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.
Nitrification, denitrification, and ammonification occur in BSF. This can be a problem when influent water is very high in nitrogen (and very low in oxygen), as nitrite and nitrate levels may increase to dangerous levels.
Experiments in a lab found that a dual media column with a layer of manganese oxide coated sand and a layer of iron hydroxide coated sand was better at removing zinc than a column with just iron hydroxide coated sand. Both were better than a plain sand column at removing bacteria.
Improving Household Drinking Water Quality: Use of BioSand Filters in Cambodia; WorldBank, W.S.P.; Laing, K.; Sobsey, M.; Stauber, C., 2010
This study found that 88% of surveyed users sustained use of their BSFs (6 months to 8 years after implementation), had 95% E. coli reduction and 47% less diarrhoea. However, recontamination of water after filtration was an issue.
A model of the cost-benefit ratios for various intervention options for reducing cholera found that digging a borehole, installing BSFs, or school-based vaccination programs are usually better than community-based vaccination programs.
More work is needed to optimize the Kanchan filter for arsenic removal. Water flows too quickly through the nail bed, so that no difference was found in influent arsenic levels and those in the filter standing head after flowing through the nails.
The authors of the Chiew et al. (2009) paper defend their methodology and results against criticisms. Differences between their results and others are likely due to water quality differences.
Children in households with a BSF had 54% less diarrhoea than in control households.
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.

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