Treatment of Parathion Wastes and Other Organics

Expansion of parathion-manufacturing facilities in Anniston, Ala., necessitated separate treatment of chemical wastes previously treated by the municipal plant. The process consists of blending the wastes, activated sludge treatment, secondary settling, and recirculation of all sludge. Acid wastes first are neutralized in a limestone pit. Suspended solids contents in the aeration basin are 15,000-18,000 mg/l, and contain less than 30 percent volatile solids. Air is supplied at 10-26 cfm/ft tank length (0.9-2.4 cu m/min/m). Some operational problems with diffusers were encountered. Reductions achieved are 95 percent of COD and nearly 100 percent of parathion and paranitrophenol after 7-10 days retention time. Residue and off-gas problems from parathion producton are being solved.