The Reclamation of Potable Water from Wastewater

The Republic of South Africa is not richly endowed with large rivers and, consequently, is examining the prospect of wastewater reuse. A biological-chemical pilot plant was initiated at Windhoek, S.W.A., for a future 1-mgd (3,785-cm m/day) reclamation plant to help solve the water shortage problem. The processes incorporated include flotation, ammonia stripping, recarbonization-stabilization, sand filtration, foam fractionation, chlorination, and activated carbon filtration. Costs of each process are included. Studies indicate that this system can produce potable water for $0.215 and $0.27/1,000 gal (3,785 1) for the final settling tank and primary clarified wastewater, respectively.