Household ceramic water filter evaluation using three simple low-cost methods : membrane filtration, 3M Petrifilm and hydrogen sulfide bacteria in northern region, Ghana

Abstract

Drinking water continues to be a major source of waterborne diseases and death in the world because many points of water collection remain unsafe. This thesis reports high level of fecal contamination found in rivers and ponds that are major sources of drinking water supply for the local communities in and around Tamale, in the Northern region of Ghana. Although considerable improvements have been made in the past few decades, greater efforts are still needed to address key issues related to the supply of safe drinking water in Tamale. There is a need to make safe water available, accessible and affordable for the local communities. One such solution is household water treatment and safe storage HWTS), which is being promoted globally by the World Health Organization, international reference to promote household water treatment and safe storage. HWTS products are sold locally by Pure Home Water (PHW in Tamale. This work explores the microbial removal and flow rate performance of two of the PHW best sellers: the CT. Filtron and the Nnsupa filter. These two filters were compared with the Everest Aquaguard, the main competitor of PHW in Tamale. The CT.

(cont.) Filtron ceramic filter is the best performer in terms of flow rate efficiency, with a rate of 1.8L/hr for the maximum water head level. Microbial analysis of the filtered water was performed for total coliform, Esdxhia coli and hydrogen sulfide (HS )-producing bacteria using three simple and low cost methods: membrane filtration (m-ColiBlue24®), 3M Petrifilm, and presence/absence (P/A) H2S tests. Again, the CT. Filtron was the most efficient. This ceramic filter was able to remove 99.5% to 100% total coliform when measured by membrane filtration and 3M Petrifilm, respectively. In addition, according to 3M Petrifilm tests, 100% removal efficiency was obtained for E. coli. As a result of the better flow rate, microbial removal and filter price for the CT. Filtron system, PHW decided to stop selling the Nnsupa candle filter. When the three simple and low cost methods were compared, the P/A H2S test often gave false positive and false negative results. On the other hand, there is a positive correlation between membrane filtration and 3M Petrifilm results. The author concludes that 3M Petrifilm is a promising approach for the detection of fecal bacteria in the developing world.

(cont.) Its ease of use, cost, ease of interpretation, low level of skill required, accuracy at high bacterial concentrations, user acceptability and low labour requirement to perform the test places it as a good screening approach for low fecal pollution and an alternative to MF (m-ColiBlue24®) at high levels of bacterial contamination.