Kenya Filter Project

Biosand Filter The Biosand filter is an innovative version of the slow sand filter specifically designed for intermittent and/or household use. These filters are produced locally at the point of need … Read More »

Biosand Filter

The Biosand filter is an innovative version of the slow sand filter specifically designed for intermittent and/or household use. These filters are produced locally at the point of need using locally available materials and labor. The installed cost of each filter is $50-$90 depending upon location, with enough daily output of 99.9% pure drinking water to meet the needs of up to 20 people.

The Biosand filter is comprised of a concrete container (the approximate size of an office water cooler) with an inset plastic pipe, and filled with layers of sand and gravel. Contaminated water is poured into the top of the filter, where a diffuser plate distributes the water over the sand bed. The water travels through the sand bed, passes through multiple layers of gravel, and collects in the plastic pipe at the base of the filter. The clean water then exits the plastic piping for the user to collect.

The removal of waterborne pathogens and contaminants occurs in the Biosand filter due to a combination of biological degradation and mechanical filtration processes. The organic material present in the contaminated water is trapped at the surface of the sand bed, forming a biological layer, or "schmutzdecke", to actively remove the pathogens and contaminants. The water produced by the Biosand filter process is odorless, tasteless, clear in color, and safe for human consumption.

« Read Less