PREPARATION OF IMMOBILIZED PHOTOSYNTHETIC BACTERIA MICROSPHERES AND DEGRADATION OF P-NITRO ANILINE.

Immobilized photosynthetic bacteria (PSB) for degrading p-nitroaniline wastewater were prepared with different embedding materials. By comparing several kinds of immobilization process, optimal embedding materials containing diatomite, sodium alginate, polyethylene glycol (PEG), and PVA were obtained. The influence of various operating conditions on the biodegradation of p-nitroaniline was systematically analyzed. Optimization of parameters revealed that the optimal operating conditions of immobilized PSB for degradation of p-nitroaniline wastewater are as follows: light, aerobic, particle size 3-4 mm, embedding ratio 14%, and microsphere dosing quantity 150 g L^-1. The degradation rate of immobilized cells was higher than that of free cells. When the concentration of p-nitroaniline is 100 mg L^-1, the removal rate was 99.2% by the immobilized cells biodegradation after 3 days. Furthermore, the immobilized bacteria maintained a high degradation rate following storage for 35 days and eight repetitions of the degradation experiment, which shows that immobilized microspheres can be widely used in p-nitroaniline degradation applications. [ABSTRACT FROM AUTHOR]