Various technologies concerning arsenic removal filters in Nepal - some important considerations
Groundwater contaminated by arsenic (As) and used as drinking water caused serious health issues in many countries of Southeast Asia. Some of the districts in the lowlands of Nepal are affected by this As pollution. The widely used filter to remove As and to make the water potable is the so-called Kanchan filter (KAF) which is well known for its efficiency, affordability, and easy maintenance. Recent surveys revealed that some filters had a rather poor performance, therefore, alternatives have been proposed but are far from being suitable for the needs of the population in Nepal as their development is time consuming and laborious. A modified KAF version is presented here with excellent results concerning efficiency according to ample field trials including ICP-MS analyses of groundwater and filtered water. The findings clearly show that the lower sand bed has be exchanged on a yearly basis, the nails can be used for several years. Beyond that, the modified filters can still be produced using local material exclusively.