Accession Number : ADD013692

Title :   Ferrous and Sulfide Treatment of Electroplating Wastewater.

Descriptive Note : Patent, Filed 10 May 85, patented 10 Nov 87,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Aldrich, James R

Report Date : 10 Nov 1987

Pagination or Media Count : 10

Abstract : The present invention involves a treatment technique for drastically reducing the volume of hazardous sludge generated by the chemical reduction of chromium contaminants and the precipitation of heavy metal contaminants from contaminated electroplating wastewater. The wastewater is first adjusted to a pH of from about 8 to 10 and then treated with sodium sulfide to provide sulfide ions to effect precipitation of heavy metal contaminants followed by treatment with ferrous sulfate or ferrous chloride to provide ferrous ions to chemically reduce the hexavalent chromium to its trivalent state. This method produces approximately one-fourth the sludge generated by the previously known acidic reaction treatment using only ferrous sulfide.

Descriptors :   *CHROMIUM, *CONTAMINANTS, *HEAVY METALS, *IRON ALLOYS, *IRON COMPOUNDS, *PATENTS, ACIDS, CHEMICALS, CHLORIDES, CONTAMINATION, ELECTROPLATING, HAZARDOUS MATERIALS, IONS, PRECIPITATION, REDUCTION, RESPONSE, SLUDGE, SODIUM, SULFIDES, VALENCE, VOLUME, WASTE WATER

Subject Categories : Water Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE