基于响应面法的流化床生物膜反应器运行条件优化

This study adopted a self-designed fluidized bed biofilm reactor (FBBR) to treat municipal wastewater. The start-up efficiency of the reactor under carriers with different configurations, filling ratio, and influent carbon to nitrogen (C/N) ratios was studied. The organic load, aeration rate, and hydraulic retention time (HRT) during stable operation period were optimized using response surface methodology. In addition, the characteristics of microbial community in different stages were analyzed. The results showed that, during the start-up period, when the filling ratio was 40%, the biomass on MFD carrier was higher, and the biofilm formation time was shorter. The maximum biomass was 66.7 mg·g^-1carrier. When the influent C/N ratio was 10:1, the removal efficiency of chemical oxygen demand (COD) and ammonia nitrogen was t he best. The optimal operating parameters of FBBR during the stable operation period were 4.18 g·m^-3·d^-1 influent organic load, 8 h HRT, and 0.66 L·min^-1 aeration. At this time, the removal efficiencies of COD, ammonia nitrogen, and total nitrogen were 91.45%±0.38%, 85.77%±0.04%, and 65.58%±0.21%, respectively. The concentrations of total nitrogen, COD, and ammonia nitrogen in the effluent were 11.0 mg·L^-1, 19 mg·L^-1, and 3.0 mg·L^-1, respectively. Proteobacteria and Bacteroideteswere the two most abundant phyla in different operation stages.