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U.S. Department of Energy
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Anaerobic wastewater treatment: Final report

Technical Report ·
OSTI ID:6965775

This project was undertaken to evaluate the effects of wastewater dilution, GAC (granular activated carbon) replacement rate, GAC particle size, operating temperature, and reactor configuration on the treatment of coal gasification wastewater with the expanded-bed GAC anaerobic bioreactor. Coal gasification wastewater used was generated in a low BTU, elevated pressure, stirred fixed-bed, gasifier operated by Morgantown Energy Technology Center (METC) in Morgantown, West Virginia. The treatability of another wastewater generated in a full-scale, slagging fixed-bed modification of a conventional dry-ash, pressurized gasifier located at the Great Plains gasification Association (GPGA) facility in North Dakota was also evaluated. Full-strength METC wastewater was found to be effectively treated at chemical oxygen demand (COD) loading rates as high as 19.4 g/kg GAC-day. At this rate, an excess of 50% of the applied COD was converted to methane, and a carbon utilization rate of 10 g GAC per liter of wastewater treated was employed. At these operating conditions, COD removal efficiencies across the treatment system exceeded 95%. Good COD removal and efficient COD conversion to methane were attainable at loading rates exceeding 70 g COD/kg GAC-day. Wastewater generated at the GPGA facility was found to be treatable at full-strength in the expanded-bed GAC anaerobic reactor at COD loading rates as high as 48 g COD/kg GAC-day. COD removal efficiencies at this loading rate exceeded 90%. Coal gasification wastewater was found to resist treatment under thermophilic anaerobic conditions. The thermophilic expanded-bed GAC anaerobic reactor affected very poor conversion efficiencies of phenol, even when fed a synthetically prepared phenol bearing wastewater. 29 refs., 77 figs., 16 tabs.

Research Organization:
Illinois Univ., Urbana (USA). Dept. of Civil Engineering
DOE Contract Number:
AC21-84MC21281
OSTI ID:
6965775
Report Number(s):
DOE/MC/21281-2562; ON: DE88001062
Country of Publication:
United States
Language:
English