分格复合填料曝气生物滤池脱氮除磷特性及微生物群落特征分析

Characteristics of microbial community,nitrogen and phosphorus removal in separated compartments of combined packing biological aerated filter

设计一种新型曝气生物滤池-分格复合填料曝气生物滤池,采用污水处理厂曝气沉砂池出水为初始微污染水,调试反应器对微污染水的深度处理效果,同时对填料表面生物膜中的微生物群落组成和结构进行解析.结果表明:该工艺在曝气量为3.0 L·min-1,水力负荷为20m3·m-3·d-1,回流比为125%的条件下,对化学需氧量(COD)、总氮(TN)、氨氮、浊度的平均去除率分别为81%、48%、91%、91%;该工艺对磷的去除率仅为14%,通过投加聚合氯化铝可使出水中总磷(TP)含量降至0.50 mg·L-1以下.微生物群落分析发现,好氧段中与硝化过程中密切相关的硝化螺菌属微生物占群落总量的8.0%,而在缺氧段与反硝化相关的脱氯单胞菌属微生物可占群落总量的1.5%,微生物群落组成与反应器功能具有较好的一致性.本研究表明,该工艺可以高效去除总氮,与聚合氯化铝联合作用可去除86%的总磷,达到污水排放一级A标准,可作为城市杂用水和景观环境用水进行回用.

A new combined packing biological aerated filter with separated compartments was designed to treat the effluent from an aeration grit chamber of sewage treatment plant. We investigated the treatment efficiency of bioreactor on slightly-polluted water and the microbial community composition and structure in biofilm attached to the carrier. The results showed that average removal rates of COD,total nitrogen,ammonia and turbidity were 81%,48%,91% and 91% respectively under the optimal conditions of the aeration fluxes of 3. 0 L·min- 1,hydraulic loading of 20 m3·m- 3·d- 1and reflux ratio of 125%. However,the phosphorus removal rate was only 14% by this bioreactor. The phosphorus concentration in effluent would be cut down to 0.50 mg·L- 1when polymeric aluminum chloride( PAC) was applied. The analysis on microbial community indicated that the Nitrospira species which was responsible for nitrification process accounted for 8. 0% of total bacteria in aerobic compartment; whereas Dechloromonas species which was related to the denitrification process accounted for 1. 5% of total bacteria in anoxic compartment. Microbial population profiles were in good accordance with the function of bioreactor. This study suggests that this bioreactor removes nitrogen with high efficiency and it is also capable of removing 86% of phosphorus with the help of PAC. This confirms that the effluent reaches wastewater discharge standard level-A and can be reused for urban miscellaneous water and scenic environment.