Preparation Of Rhodococcus Erythropolis Beads Immobilized With Nano Al₂O₃ And Degradation Of Phenol

Phenol belongs to high toxic compounds, the body will appear acute toxic reaction after a certain amount of phenol, long-term drinking by phenol pollution of water bodies can cause itching, anemia, dizziness, and nervous system disorders. Containing phenol wastewater not only has a great harm to human, but also will cause harmful effects to the animals and plants. So how to solve the phenol water pollution effectively has become the hot topics to government and the environmental protection workers.Al-alginate was used as major embedding materials, nano Al₂O₃ was used as additives, selected Rhodococcus erythropolis to prepare immobilized algal-bacterial beads.Then use the beads to the degradation of phenol. Firstly, to get the optimal preparation plan, the orthogonal experiment design of nano Al₂O₃ immobilized bacteria preparation condition was optimized. Then the nano Al₂O₃ immobilized beads were characterized and the structure of the new compound material properties were observed thoroughly. Later, the optimum degradation of phenol conditions were detected to get the best degradation conditions. Finally the recycling effect of nano Al₂O₃ immobilized beads was discussed.The results demonstrated that the optimum conditions for preparation of immobilized algal-bacterial beads were（the volume of sodium alginate solution was 3 m L） nano Al₂O₃ amount of 0.05 g, sodium alginate mass concentration of 6%, the microorganism embedding capacity of 1.5m L and aluminum sulfate mass concentration of 3%. Through the detection of ESEM and specific surface area analyser, finding that abundant Rhodococcus erythropolis mycelium embedded in the beads.The adding of nano Al₂O₃ to the beads provide enough space to the Rhodococcus erythropolis, improving the degradation rate of phenol. The majority of the internal diameter are mesoporous rang from 2 nm to 30 nm, offering a passageway for the nutrients and target contaminants entering into the beads.The optimal conditions of phenol degradation are 8 g/L immobilized algal-bacterial beads, p H 8.0, 30 R. The phenol concentration of 400 mg/L was completely degraded after 24 h under the optimal conditions.After being reused for five times, the nano Al₂O₃ immobilized beads ensure that the degradation rate of phenol maintained higher than 93% each time, which showed it maintained a stable biological activity and high repeatable utilization rate, also possessed favorable reusability.