铝盐对活性污泥微生物菌群及其除污性能的影响

Influence of Aluminum Salt on Microbial Community in Activated Sludge and Pollutant Removal

在污水处理中经常通过投加铝盐混凝剂进行化学除磷和强化造粒,但其对活性污泥中微生物群落的影响尚不明确。为此,采用SBR反应器考察了聚合氯化铝(PAC)的投加对活性污泥微生物菌群及其除污性能的影响。结果表明,PAC的投加使反应器内的MLSS和MLVSS浓度提高了约1倍,而单位质量污泥的生物量提高了约2倍。根据荧光原位杂交(FISH)技术的检测结果,投加PAC后,污泥中的细菌总数有所增加,而亚硝化菌和硝化菌所占比例基本没变。PAC的投加大幅度提高了对TP的去除率,对COD的去除效果也得到改善,但对硝化和反硝化过程的影响不明显。在稳定运行条件下,出水中的铝残留浓度基本在0.5 mg/L以下,说明90%以上的铝转移到了污泥中。

Aluminum salt coagulant is widely used for chemical phosphorus removal and enhancing granulation in sewage treatment, but its influence on the microbial community in activated sludge is not clear. The influence of adding polyaluminium chloride （PAC） on the microbial community and pollutant removal was investigated in a set of SBR. The results showed that MLSS and MLVSS concentrations were almost doubled in the reactor after PAC addition, while biomass per unit weight of sludge increased by about 2 times compared with the reactor without PAC addition. As a result of the fluorescence in situ hybridization （FISH） test, the amount of the total bacteria increased in the reactor after PAC addition, while the proportions of nitrosobacteria and nitrobacteria were unchanged. PAC addition significantly increased the removal efficiency of TP, and COD removal was improved, but PAC addition had no obvious effect on nitrification and denitrification. Under stable operational conditions, the residual aluminum concentration in the effluent was less than 0. 5 rag/L, indicating that more than 90% of the aluminum was transferred into the sludge.