Accession Number : ADA299261

Title :   Field Evaluation of an Envirex GAC Fluid-Bed Bioreactor Treatment of Chlorobenzene in Groundwater.

Descriptive Note : Final technical rept. Jun 93-Feb 94,

Corporate Author : DOW CHEMICAL CO MIDLAND MI

Personal Author(s) : Klecka, G. M. ; McDaniel, S. G. ; Wilson, P. S. ; Carpenter, C. L. ; Clark, J. E.

PDF Url : ADA299261

Report Date : FEB 1995

Pagination or Media Count : 103

Abstract : Although granular activated carbon (GAC), fluidized-bed bioreactors have been widely used for treatment of groundwater containing readily biodegradable organic compounds, there is only limited experience with treatment of chlorinated organics found at many DOD and industrial sites. This report summarizes performance data from a field evaluation of an Envirex model 30 bioreactor operated at various chlorobenzene concentrations and organic loading rates over a 7-month period. The work was conducted under a collaborative research and development agreement between US Air Force Armstrong Laboratory and the Dow Chemical Company. Microorganisms used to seed the bioreactor were provided by activated sludge from the site, as well as indigenous chlorobenzene-degrading bacteria present in the groundwater. Removal efficiencies exceeding 99.99% were achieved at organic loading rates between 6 and 10 pounds of total oxygen demand (lb TOD) per 25 cubic feet per day and hydraulic residence times of 7 minutes. Influent chlorobenzene concentrations ranging from 100 to 170 ppm were consistently reduced to below the detection limit of 10 ppb. Additional studies conducted at loading rates in excess of 10 pounds TOD per 25 cubic feet per day were useful for identifying critical operating parameters and potential system improvements, but were not representative of performance at lower loadings. Economic evaluation suggested that groundwater treatment costs for the bioreactor were lower than other conventional technologies. (AN)

Descriptors :   *WATER TREATMENT, *GROUND WATER, *BIODEGRADATION, *FLUIDIZED BED PROCESSES, *CHLOROBENZENE, ECONOMIC ANALYSIS, COST EFFECTIVENESS, CHEMICAL CONTAMINATION, BACTERIA, COMPARISON, FIELD TESTS, EFFICIENCY, OXYGEN, CHEMICAL REACTORS, ACTIVATED CARBON, WATER POLLUTION, FLOW RATE, SOLVENTS, WATER QUALITY, CONCENTRATION(CHEMISTRY), STOICHIOMETRY, GRANULES, BIODETERIORATION, ACTIVATED SLUDGE PROCESS.

Subject Categories : Organic Chemistry
      Water Pollution and Control
      Biochemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE