KINETIC ANALYSIS OF INHIBITORY SUBSTRATE DEGRADATION IN BIOAUGMENTED ACTIVATED SLUDGE PROCESS

Abstract

A steady-state model coupling Haldane kinetics and mass conservative principles was developed herein to depict the degradation of a single inhibitory substrate in a bioaugmented activated sludge reactor. The substrate toxicity impact on the bioaugmentation was evaluated for three levels of inhibition coefficient K_i: 0.1, 10, and 1000 mg/L. Under high toxicity conditions of K_i = 0:1 mg/L, the input biomass markedly enhanced the substrate removal. However, at less toxicity of K_i >10 mg/ L, the input biomass was ineffective. The sensitivity study confirmed the parameters of k, K_s, and b_d has no connection with K_i, but depends on the amounts of degradative bacteria inside the reactor. Alternatively, parameter Y is important only when K_i is greater than 10 mg/L and the bacteria significantly utilize the substrate. In addition, a novel indicator of marginal solids retention time examines the economic advantages of adding biomass as compared to extending the solids retention time.

Keywords:

• Bioaugmentation
• Haldane kinetics
• Sensitivity analysis
• Toxic substrate

Acknowledgments