硫酸铝投加量对前置A^2/O除磷及活性污泥性能的影响

The Effects of Al_2(SO_4)_3 Dosages on the Phosphorus Removal and Activated Sludge in Prepositive A^2/O Process

为保证城镇污水厂出水总磷达标排放,以A^2/O工艺为研究对象,采用生物除磷与前置化学除磷相耦合的方法,重点考察Al_2(SO_4)_3投加量对出水TP含量以及反应器内活性污泥性能的影响。结果表明,铝、磷摩尔比为1:1时,出水COD和TP、NH4^+-N、TN含量均达到了GB 18918-2002的一级A标准;铝、磷摩尔比为0.5:1时,出水TP的质量浓度则高达2.0 mg/L左右。铝、磷摩尔比为1:1时,好氧污泥SVI由投药前的87.4 m L/g降至74.2 m L/g,ζ电位由-4.73 m V降至-7.16 m V,氧吸收速率由3.185 mg/(g·min)升到3.462 mg/(g·min),胞外聚合物(EPS)的总量由66.25mg/g升到105.2 mg/g,蛋白质与多糖的质量比由5.23降至2.09,表明污泥活性、沉降性能、脱水性能增强。进行好氧污泥微生物群落结构分析,发现铝、磷摩尔比为1:1时微生物种属由投药前8种减为5种,微生物丰度降低,拟杆菌和绿弯菌的比例有所上升,与变形菌一起成为反应器内优势菌群。

To ensure that the TP in diluent of urban wastewater treatment plant meets the discharge standard, this study took the A2/O process as the research object and the combination of biological phosphorus removal and pre chemical phosphorus removal was adopted to mainly investigate the effects of Al2（SO4）3 dosage on the content of TP in effluent and activated sludge characteristics in the reactor. The results showed that the COD and content ofTP, TN, NH4- N in effluent reached first grade A standards of GB 18918--2002 when the molar ratio of P to Al was 1：1, and the mass concentration of TP in effluent was up to about 2.0 mg/L when the ratio of P to A1 was 0.5：1. When the molar ratio of P to A1 was 1：1, the SVI and ζ potential reduced from 87.4 mL/g and -4.73 mV to 74.2 mL/g and -7.16 mV respectively, the Oxygen Uptake Rate increased from 3.185 mg/（g.min） to 3.462 mg/（g.min）, and the amounts of Extracellular Polymeric Substances （EPS） increased from 66.25 mg/g to 105.24 mg/g and the mass ratio of protein to polysaccharide reduced from 5.23 to 2,09, indicating that the activity of slud, the sedimentation performance and the dewatering performance were reinforced. The analysis results of microorganism community smacmre of aerobic sludge showed that after a dosage, microbial species reduced from 8 to 5, and bacterial abundance decreased while the rate ofbacteroidetes and chloroflexi increased and became an advantage bacterium group together with proteobacteria within the reactor.