Arsenic Contamination of Groundwater and Selected Removal Technologies for Rural Isolated Communities in Bangladesh

摘要

Groundwater contamination by arsenic is a major concern in Bangladesh where about 97% of the total rural population depend on tube-wells for drinking water, which is bacteriologically safe to drink. Arsenic in groundwater above 50 μg/l (Bangladesh standard for Drinking Water) was found in 61 districts out of total 64 districts and 433 out of the 496 thanas in Bangladesh. But this dimension of the arsenic occurrence problem in groundwater in Bangladesh is yet to be fully identified. The total population exposed to arsenic contaminated water above 50 μg/l and 10 μg/l are in the range of 28.1 - 32.5 million and 46.4 - 56.7 million respectively. The incidences of excess skin cancer are 0.29%, 0.043% and 0.012% from drinking arsenic contaminated water at the present level of arsenic contamination, satisfying the Bangladesh Standard (50 μg/l) and satisfying WHO guideline value (10 μg/l) respectively. In the context of the prevalence of high concentrations of arsenic in groundwater in Bangladesh, several methods/ technologies of treating water for arsenic reduction from drinking water have been tried. In many cases conventional technologies have been scaled down to suit the rural isolated households and communities to provide safe sources of water for drinking purpose. Recently a number of research studies have been conducted in Bangladesh to identify such novel technologies to remove arsenic from groundwater in rural isolated communities. This study presents a brief overview of some of these processes and technologies.