Evaluation of the complementary use of the ceramic (Kosim) filter and Aquatabs in Northern Region, Ghana

Abstract

The Kosim filter is a ceramic water filter that is currently used in Northern Ghana. Based on prior MIT research in Northern Ghana, this technology is effective at removing 92% of turbidity, 99.4% of total coliforms, and 99.7% of E. Coli from unimproved water sources. However, the product water is still microbially contaminated. The purpose of this thesis is to explore the effectiveness of combining two household water treatment technologies, the Kosim filter and Aquatabs, in order to achieve a more effective and complete water treatment system. Aquatabs are sodium dichlorisocyanurate chlorine tablets that are used on the household scale. They are particularly effective at killing pathogenic bacteria; however, they have predominantly been applied in emergency relief situations and have never, apart from one research study conducted by the Center for Disease Control, previously been applied in Ghana. In this study, 59 rural households (24 in a lower-class community and 35 in a lower middle-class community) in possession of Kosim filters were visited as part of a three week pilot study. During the initial visit, households were surveyed about the use and perception of their Kosim filters, they were trained in the use and given a one week supply of Aquatabs, and their Kosim filtered water (without Aquatabs) was tested. After one week, the same households were re-visited. A similar survey was conducted about the use and perception of the combined Kosim filter and Aquatabs system, and the filtered and chlorine disinfected water was tested. The addition of Aquatabs to the Kosim filtered water significantly reduced the microbial contamination; however, it did not completely remove pathogenic bacteria.

(cont.) The average total coliform concentration in the drinking water was reduced by 50% compared to the filtered-only water, and the percentage of households with no total coliform concentration increased from 44% to 64%. Furthermore, the percentage of households with no E. Coli in their drinking water increased from 88% to 98%. In terms of user acceptability, all of the survey respondents indicated that the Aquatabs "improved the taste of the water" as they associated it with municipally treated or bottled water, suggesting that the chlorine taste is acceptable to these potential consumers.