Accession Number : ADA323448

Title :   User Data Package and Operation Test Report for the Implementation of the Sodium Sulfide/Ferrous Sulfate Process at Navy IWTPS.

Descriptive Note : Final rept. Oct 94-Sep 96,

Corporate Author : NAVAL FACILITIES ENGINEERING COMMAND ALEXANDRIA VA

Personal Author(s) : Durlak, Edward

PDF Url : ADA323448

Report Date : FEB 1997

Pagination or Media Count : 145

Abstract : The ferrous sulfate/sodium sulfide (FS/SS) process is a treatment technology for the reduction of hexavalent chromium and precipitation of heavy metals in industrial wastewater treatment plants (IWTPs). When the ferrous ion, as ferrous sulfate, is mixed with sulfide, the hexavalent chromium is rapidly reduced to its trivalent state at a neutral pH and then precipitated. FS/SS technology can be used to replace the current hydroxide treatment chemistry. This report presents the results and lessons learned from full-scale implementation of FS/SS. The FS/SS treatment process reduced the volume of sludge generated by 20 to 30 percent, reduced the amount of treatment chemicals, and resulted in over $35,000 annual savings. Furthermore, metal sulfides tend to be two to three orders of magnitude less soluble than their corresponding metal hydroxides. This gives cleaner effluent, which helps the facility meet environmental requirements. Further benefits include the removal from the shop area of the high pressure sulfur dioxide cylinder (used in the hydroxide process), a faster and more reliable chrome reduction method, neutral pH operation that extends tank and equipment life, and less acid and caustic chemicals stored on the shop floor. As Navy activities do more with less, the FS/SS process can help meet increasingly stringent standards.

Descriptors :   *WASTE WATER, *WATER TREATMENT, *SULFIDES, *HEAVY METALS, *CHEMICAL CLEANING, IRON COMPOUNDS, INDUSTRIAL PLANTS, CHEMICAL PRECIPITATION, PH FACTOR, SLUDGE, SODIUM COMPOUNDS.

Subject Categories : Solvents, Cleaners, and Abrasives
      Water Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE