Inhibition concentration of phenolic substances under different cultivation conditions.: Part I:: phenol oxidation by mixed microbial population in a model system

The effects of oxygen supply rate and the presence or absence of nutrients on the kinetics of phenol degradation and oxygen consumption by a mixed microbial population were tested in a model system. The values for the maximum specific rate of phenol degradation (q(Smax)), the saturation constant (K-S), and the inhibition concentration (S-CR) were determined for unlimited growth (K-La = 340 h(-1), growth medium) with 1.7 mmol g(-1) h(-1), 65 mg L-1, and 190 mg L-1. Under limitation conditions, alterations occur depending on the type of limitation. Nutrient limitations lead to values of 0.8 mmol g(-1) h(-1), 45 mg L-1, and 160 mg L-1, and oxygen limitations lead to 1.2 mmol g(-1) h(-1), 30 mg L-1, and 120 mg L-1, respectively. The results suggest that with excess oxygen, the rate of phenol degradation was higher and the inhibition effect of phenol was suppressed to some extent. Under the same high oxygen supply rate, the presence of nutrients in the model water significantly supported the phenol degradation rate.