Ion-exchange resin for removing hexavalent chromium from ground water at treatment facility C: Data on removal capacity, regeneration efficiency, and operation

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:474023

Bahowick, S; Dobie, D; Kumamoto, G ^[1]

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1. Lawrence Livermore National Lab., CA (United States)

Lawrence Livermore National Laboratory (LLNL) is operated for the Department of Energy by the University of California. In July 1987, LLNL was placed on the National Priorities List based on the presence of volatile organic compounds (VOCs) in ground water. The July 1992 Record of Decision stipulates air stripping for treatment of VOCs and ion-exchange to treat chromium in the ground water for Treatment Facility C (TFC). TFC, which was activated in October 1993, was designed to treat influent ground water at 60 gpm with concentrations of hexavalent chromium averaging 30 ppb. The ion exchange system removes the hexavalent chromium to below its limit of detection (2 ppb). The resin used is a strongly basic Type I quaternary ammonium anion exchange resin with a styrene-divinylbenzene copolymer gel matrix. The total hexavalent chromium removed from the ground water as of October 8, 1995 was 660 grams. An initial operating capacity was achieved of 6.4 grams CrO{sub 4}{sup 2{minus}} removal per ft{sup 3} of resin, but this was observed to vary over the next two years. Variation was observed in the rate of breakthrough. The regeneration process was optimized to minimize waste produced and maximize regeneration of the resin. Elevated levels of chloride, sulfate, nitrate, potassium 40 and uranium have been observed in the regeneration waste. Because of the potassium and uranium content, the regenerated waste had to be disposed of as mixed waste.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 474023
• Report Number(s): CONF-960804--Vol.2
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
CHROMIUM
GROUND WATER
ION EXCHANGE
LAWRENCE LIVERMORE NATIONAL LABORATORY
REMEDIAL ACTION
SEPARATION PROCESSES