THE EFFECT OF COSUBSTRATES ON PHENOL DEGRADATION KINETICS

Kinetic parameters (based on the Monod model) for phenol degradation w ere measured under single and multiple substrate conditions using batc h or fed batch reactor (FBR) techniques. The batch reactor was equival ent to the FBR for q(m) estimation, but gave higher K-s estimates (5.1 4 +/- 7.34 batch vs. 0.63 +/- 0.86, mg/l as phenol), q(m) was signific antly higher with single substrate than multiple substrate feed (120.4 +/- 53.9 for phenol only vs. 59.5 +/- 23.7 for multiple substrates, m g/g-h); an active biomass correction factor based on the fraction of p henol organic carbon in the stock feed reversed this inequality, but t he difference (120.4 +/- 53.9 for phenol only vs. 202.5 +/- 80.7, corr ected, for multiple substrates, mg/g-h) remained significant. K-s was independent of feed composition (0.63 +/- 0.86 mg/l as phenol). Paired FBR tests were used to minimize changes in sludge condition, and agre ed with unpaired tests. probability distribution analysis showed that q(m) and K-s data followed log-normal distributions (r(2) > 0.90), and is useful for selecting values for design.