PDU scale nitrification/denitrification of pretreated coal gasification wastewater

Conference · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5915570

Gallagher, J R; Shockey, R E; Turner, C D; Mayer, G G

Cooling tower tests with the stripped gas liquor (SGL) demonstrated that biological treatment to reduce the organic loading was sufficient for satisfactory operation of the tower at 10 cycles of concentration. However, ammonia stripping remained at high levels, which could result in industrial hygiene and nuisance odor concerns, environmental damage and, after longer periods of acclimation, lead to biofouling in the cooling tower from nitrification. These concerns coupled dishcharge to receiving waters, prompted research into biological nitrogen removal. As a result of this research, the following conclusions have been drawn: (1) Great Plains Gasification Plant (GPGP) stripped gas liquor, pretreated by biological oxidation, can be nitrified. Complete nitrification can be obtained at influent concentrations of greater than 500 mg/1 as NH/sub 3/-N. (2) The highest removal rates and best system stability was found at the highest solids retention time (SRT). The low SRT reactor (12 days) did not attain stable operation until after approximately 110 days of operation. The ammonia removals during steady-state operation were 97.7%, 96.9% and 96.9%, respectively for reactors N1 through N3 (SRTs of 37, 21 and 12 days). (3) Influent ammonia-N spikes up to 1020 mg/l were observed. At these high levels, inhibition was observed at all three SRTs. However, when concentrations fell to typical values (500 mg/l NH/sub 3/-N) the systems recovered rapidly. (4) Denitrification of biologically treated and nitrified GPGP SGL was complete in an activated sludge reactor using a 4 day HRT, 10 day SRT and a 2.47:1 molar ratio of methanol to NO/sub 3/-N as the supplemental carbon source. (5) Nitrate-N concentrations in the influent greater than 750 mg/l were completely denitrified demonstrating a maximum observed specific removal rate of 92.8 mg NO/sub 3/-N/mg MLVSS-day. 16 refs., 10 figs., 4 tabs.

• Research Organization: North Dakota Univ., Grand Forks (USA). Energy Research Center
• DOE Contract Number: FC21-83FE60181
• OSTI ID: 5915570
• Report Number(s): DOE/FE/60181-173; CONF-860527-1; ON: DE86010578
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404 -- Coal
Lignite
& Peat-- Gasification
010800* -- Coal
Lignite
& Peat-- Waste Management
ACTIVATED SLUDGE PROCESS
AIR POLLUTION
AMMONIA
BIODEGRADATION
BIOLOGICAL FOULING
CHEMICAL REACTIONS
COAL GASIFICATION PLANTS
CONDENSATES
COOLING TOWERS
DATA
DECOMPOSITION
DENITRIFICATION
ENERGY TRANSFER
EXPERIMENTAL DATA
FOULING
FUNCTIONAL MODELS
HEAT TRANSFER
HYDRIDES
HYDROGEN COMPOUNDS
INDUSTRIAL PLANTS
INFORMATION
LIQUID WASTES
MANAGEMENT
MECHANICAL STRUCTURES
NITRIFICATION
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NUMERICAL DATA
OXYGEN COMPOUNDS
POLLUTION
PROCESS DEVELOPMENT UNITS
PROCESSING
REMOVAL
TIME DEPENDENCE
TOWERS
WASTE MANAGEMENT
WASTE PROCESSING
WASTE WATER
WASTES
WATER
WATER REQUIREMENTS
WATER TREATMENT