Enhanced industrial wastewater treatment

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:353577

Nachabe, A H; Durlak, E ^[1]

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1. Naval Facilities Engineering Service Center, Port Hueneme, CA (United States)

The sodium sulfide/ferrous sulfate (SS/FS) process is a treatment technology for the reduction of hexavalent chromium and precipitation of heavy metals in industrial wastewater treatment plants (IWTP). 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. SS/FS technology can be used to replace the current hydroxide treatment chemistry in Navy IWTPs. This paper will present the results and lessons learned from full-scale implementation of SS/FS at Naval Undersea Warfare Center (NUWC) Keyport, Washington. The SS/FS treatment process reduced the chemical cost by fifty nine percent and sludge disposal cost by thirty one percent. On an annual basis total cost savings amounted to $31,950 or thirty four percent. The SS/FS treatment process lowered the amount of treatment chemicals used in the IWTP. Furthermore, metal sulfides tend to be two to three orders of magnitude less soluble than their corresponding metal hydroxides. This allows for cleaner effluent, which will help the facility meet environmental discharge 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 respond to the ever increasing pressures to do more with less, the SS/FS process can help them meet the increasingly stringent standards.

• OSTI ID: 353577
• Report Number(s): CONF-970677--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
CHROMIUM
COST
INDUSTRIAL WASTES
IRON SULFATES
MILITARY FACILITIES
SODIUM SULFIDES
TECHNOLOGY ASSESSMENT
WASTE PROCESSING
WASTE WATER
WATER TREATMENT PLANTS