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WATER FILTRATION FOR ASBESTOS FIBER REMOVAL
Citation:
Logsdon, G. WATER FILTRATION FOR ASBESTOS FIBER REMOVAL. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-79/206 (NTIS PB80135379), 1979.
Description:
This report presents a comprehensive review of data on removal of asbestos fibers by granular media filtration and diatomaceous earth filtration. It summarizes data obtained in pilot plant studies at Duluth and Seattle, in research program carried out at Duluth's Lakewood filtration plant, and monitoring at Silver Bay and Two Harbors, Minnesota plants, Chicago, Philadelphia, and in the San Francisco Bay area. Chrysotile and amphibole fiber concentrations in drinking water can be substantially reduced by granular media filtration. Reductions of up to 99.99 percent were reported during storm conditions at Duluth, Minnesota. Effective granular media filtration required careful control of pH, coagulant doses, and filtered water turbidity. Research to date indicates that coating the diatomaceous earth filter aid with aluminum hydroxide substantially increases the removal of both amphibole and chrysotile fibers. Duluth results indicate that filtered water turbidity should be 0.10 ntu for most effective fiber removal.