Preparation Of Immobilization Carriers For Candida Tropicalis And Investigation On Phenol-Degrading Characteristics

The principle and application of immobilization are elucidated. The key conditions under which cell was immobilized with a mixed carried process using alginate gel and polyvintl alcohol (PVA)as major entrapping material were studied. It was found that the mixed carrier process effectively solved problems that the immobilized cell techonology applied in wastewater treatment faced,such as difficulty in forming spherical particles,ease of the particles to be broken,loss of the activity in producing methane and floatation of the particles .The optimum PH of the immobilized cells was 6.0 and the optimum temperature was 30℃. SEM images demonstrated that the bacteria immobilized in calcium alginate can grow and reproduce well.The study was conducted to evaluate the degradation kinetics of yeast.A degradation kinetics model was found.Based on the flask culture conditions,the phenol degradation were performed in a small fermentor.The kinetics of degradation were studied.The dissolved O2 kineticrate constant(Ko)were determined by using a linear estimation method.A mathematical model was proposed to simulate the batch phenol biodegradation process in immobilized system, which took into account the internal and external mass transfer resistances of phenol and oxygen and the double-substrate phenol-oxygen intrinsic kinetics. The validation of this model was done by the comparison between the model simulations and the experimental measurements of phenol concentration profiles in the main liquid phase. In addition, the time and radius courses of phenol, oxygen and cell concentration profiles within the alginate gel beads were reasonably predicted by the proposed model.