Slow sand filtration for cercariae removal in rural Egypt

Abstract

In 1990, El‐Mansoura University (Egypt) signed a contract with the International Development Research Center to conduct an integrated research to field test the process of slow sand filtration. One of the many purposes of this project was to demonstrate the efficiency of slow sand filtration in removing cercariae. A pilot plant was constructed and installed in Sandoop Compact Water Treatment Plant in El‐Mansoura City. The pilot plant consisted of an intake, upflow roughing filter and four slow sand filters. The raw water source was El‐Bahr El‐Saghier Canal, a branch of the River Nile. A slug of 10000 cercariae units in 11 was dropped on the water surface at each of three filters, no presence of cercariae at the final effluent of the SSF was detected. At some depths across the sand layer positive samples were identified. During this study 20 samples from the effluent of the tested slow sand filters; the URF, and the compact treatment plant were collected. Out of the 20 positive samples after the slow sand ...