Abstract & Overview
The household biosand filter (BSF) is one of the world’s most utilized point-of-use (POU) water treatment tools where drinking water is not reliably potable. The feasibility of using ferrocement for construction, the filter volume, and the effect of temperature on removal are unclear, however. The following field and laboratory research was carried out in Panama and at Michigan Technological University. Field testing of ferrocement biosand filters (FBSFs) in rural Panama yielded average coliform and E.coli removals that compared favorably to plastic and cement BSFs. Parallel testing of a larger-bodied FBSF and a conventionally-sized BSF revealed that the former is necessary to sufficiently purify dose volumes greater than the recommended 12 liter influent. Additionally, for optimal treatment, no more than approximately three-quarters of the total pore volume should be introduced per day. Model filters in different temperature labs showed that while immediate filter performance varies by temperature, over time, BSF performance adjusts to be similar for all tested temperature values. Finally, exposure to extremely reduced temperatures and freezing severely reduced filter performance compared to control filters.