Study on the degradation of cotton pulp black liquor in a bubble-column reactor

Degradation of cotton pulp black liquor by Pleurotus ostreatus Bl in a bubble-column reactor (BCR) was studied. Under the optimal conditions, batch experiments and kinetic analysis were conducted. The results show that under the optimal conditions, the BCR was run for four cycles (each cycle, 12 days). Even after four cycles, strain Bl can still decolorize cotton pulp black liquor effectively. And the same mycelial pellets were reused, which would bring great economic benefits. The ultimate decolorization and COD removal rates are 76% and 80%, respectively. The substrate degradation kinetics of stain Bl corresponds to typical substrate inhibition model. The model parameters are estimated with non-linear regression method, the values are as follows: η_max=0.594 d^-1, K_s=3865 mg · L^-1, K_i=17038 mg · L^-1. The experimental data verification for the model equation is satisfactory.