A case study in the treatment of spent pickling acids for fluoride compliance at a metals finishing facility

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:367604

Francis, J T; Walters, J; Evans, D ^[1]

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1. Parsons Engineering Science, Pasadena, CA (United States)

A metal finishing facility located in the Los Angeles area processes coiled steel sheets (300 and 400 series) and other sheet metal alloys by annealing, pickling and cold rolling operations. The facility acquires steel from large manufacturers or mills and finishes to a prescribed thickness, hardness, and grade depending on customers needs, for sale to metal product manufacturers such as can manufacturers and prefabricated steel building industries. Specialty metal alloys such as nickel-cobalt or titanium are also processed for use in aerospace industry applications. The facility produces about 10,000 tons of metal sheets per year and in the process generates about 40,000 gallons per day (gpd) of wastewater that is pretreated for metals removal and discharged to the sewer. About 30,000 gallons per month of spent acid are generated--much of which is used for pH adjustment in the pretreatment system. Acids of concern are sulfuric acid, hydrofluoric acid and nitric acid. The wastewater treatment system (WWTS) is equipped for chromium reduction and metals precipitation and handles the wastewater, the spent acids and other alkaline wastes generated at the facility. An estimated 50 tons of hazardous waste sludge are generated and disposed of on a monthly basis.

• OSTI ID: 367604
• Report Number(s): CONF-951124--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
HAZARDOUS MATERIALS
HYDROFLUORIC ACID
METAL INDUSTRY
NITRIC ACID
SULFURIC ACID
WASTE PROCESSING
WASTE WATER
WATER POLLUTION ABATEMENT