Biological treatment of Hygas coal gasification wastewater

Technical Report · Fri Dec 01 04:00:00 EST 1978

OSTI ID:5368784

Luthy, R G; Tallon, J T

An eight month experimental study was performed to assess biological treatability characteristics of Hygas coal gasification process pilot plant wastewater comprised of cyclone and quench condensates. The study evaluated treatability characteristics of ammonia stripped and unstripped wastewater at full strength and at 1:1 dilution. It was determined that minimum pretreatment required for biological oxidation consisted of reducing wastewater alkalinity, and decreasing raw ammonia concentration by dilution or by stripping. Kinetic studies with stripped Hygas wastewater showed the waste could be processed at mean cell residence times varying from 10 to 40 days with hydraulic residence times of 2 to 3 days; the bacteriological yield coefficient was 0.11 (COD basis), and the decay coefficient was 0.02/day. The study also determined correlations for dissolved oxygen uptake, the effect of COD removal rate on zone settling velocity and sludge volume index, removal efficiencies for various constituents, and adsorption isotherms for biological effluent COD on activated carbon and process char. Nitrification was completely inhibited in this study; it was suspected that this was due in part to high wastewater boron concentration (80 to 110 mg/l), however, additional testing to assess effects of potentially toxic organic compounds is required to confirm this observation. Hygas wastewater seemed to inhibit bacteriological growth because mean cell residence times less than 10 days do not appear feasible and because apparently higher yield coefficients were observed with diluted wastewater. A literature review showed that there are differences in wastewater characteristics between coke plant weak ammonia liquors and high strength coal gasification process effluents.

• Research Organization: Carnegie-Mellon Univ., Pittsburgh, PA (USA). Center for Energy and Environmental Studies
• DOE Contract Number: EX-76-S-01-2496
• OSTI ID: 5368784
• Report Number(s): FE-2496-43
• Country of Publication: United States
• Language: English

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BACTERIA
BIOCHEMICAL OXYGEN DEMAND
BIOCHEMICAL REACTION KINETICS
BIODEGRADATION
CHEMICAL COMPOSITION
CHEMICAL OXYGEN DEMAND
CHEMICAL REACTIONS
COAL GASIFICATION
CRYOGENIC FLUIDS
DECOMPOSITION
DIAGRAMS
ELEMENTS
ENVIRONMENTAL QUALITY
FLUIDS
FUNCTIONAL MODELS
GASIFICATION
GROWTH
HYDROGEN COMPOUNDS
HYGAS PROCESS
KINETICS
LIQUID WASTES
MICROORGANISMS
NONMETALS
OXIDATION
OXYGEN
OXYGEN COMPOUNDS
PH VALUE
PILOT PLANTS
REACTION KINETICS
REMOVAL
SEDIMENTATION
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SNG PROCESSES
THERMOCHEMICAL PROCESSES
UPTAKE
WASTE WATER
WASTES
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