This demonstration was performed to study the operation, performance and economics of a new sulfide precipitation process ('Sulfex'TN), for treating metal finishing wastewaters. The study was performed by Holley Carburetor Division of Colt Industries, with assistance from the Permutit Company, at the carburetor manufacturing plant in Paris, Tennessee. Here 'Udylite' processes are used for chromate conversion coatings on aluminum and zinc parts before assembly. A newly installed SulfexTN system removes chromium and zinc from the plant's metal finishing wastewater. It also removes suspended material such as precipitated aluminum, iron and phosphates. Major steps in the system are: equalization and neutralization of untreated wastewater, precipitation of metals and sedimentation of suspended solids, polishing of settler effluent with dual media filtration, and final dewatering of settled sludge. Results show all metals and suspended solids were removed to levels well below both the city sewer system limitations and the state guidelines. Excellent sludge dewatering resulted in the filter press without use of additional conditioning agents. No hydrogen sulfide odor was detected from the reaction process, treated effluent, or the solid waste produced. Jar tests were used for controlling effective wastewater treatment and economical operation.

Sponsored by Industrial Environmental Research Laboratory. Final report. Microfiche.