Effect of mass transport limitation on nitrification in the activated sludge process

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6757050

Song, S

A pseudo-homogeneous model of the nitrifying activated sludge process was developed to investigate the effects of mass transport resistance and heterotrophic/nitrifier competition on the apparent relationship between DO concentration and nitrification. The kinetics of both heterotrophic carbon oxidation and autotrophic NH/sub 4//sup +/-N oxidation within activated sludge flocs were described by interactive-type multiple-substrate limiting models. The values for the model's parameters were estimated from a series of experiments that were conducted in a laboratory-scale nitrifying activated sludge reactor system. The experimental results indicated that the intrinsic relationship between DO concentration and nitrification should be modeled with the exponential function rather than the Monod function. Using the estimated parameter values, the model was then used to simulate steady state nitrification over a range of typical MCRT's, DO concentrations, and levels of mass transport resistance. The effect of mass transport resistance on nitrification following an organic shock load was also simulated. It was found that while the nitrifiers' intrinsic half-saturation coefficient for DO is about 0.5 mg/L, varying mass transport effects, MCRT's, and heterotrophic/autotrophic competition for DO can combine to give apparent limited DO concentrations that range from 0.5 mg/L to as high as 4.0 mg/L.

• Research Organization: California Univ., Riverside (USA)
• OSTI ID: 6757050
• Country of Publication: United States
• Language: English

Related Subjects

510200* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
BENCH-SCALE EXPERIMENTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL TRANSPORT
KINETICS
MASS TRANSFER
MATHEMATICAL MODELS
NITRIFICATION
ORGANIC COMPOUNDS
REACTION KINETICS
SEWAGE
SEWAGE SLUDGE
SLUDGES
WASTES