镍对活性污泥生物除磷的影响及其机理

摘要

以实际生活污水为研究对象,在序批式活性污泥反应器中探究了Ni2+对活性污泥形态及生物除磷性能的影响.实验结果表明,Ni2+能够抑制生物除磷,当Ni2+质量浓度由0 mg/L增加至10.0 mg/L时,PO43--P去除率由93%下降至12%.机理研究结果表明:Ni2+能抑制聚磷微生物的厌氧释磷和好氧吸磷,并能抑制内聚物聚羟基烷酸酯(PHA)的合成;当Ni2+质量浓度为10.0 mg/L时,PHA的最大含量仅为2.4 mmol/g (以单位质量挥发性悬浮物所含PHA中C的物质的量计),远低于空白组中PHA的含量.此外,Ni2+还对微生物群落的组成产生影响,并促进活性污泥中聚糖微生物的增殖.%The effect of Ni2+on morphology and biological phosphorus removal capability of activated sludge was investigated in a sequencing batch reactor using actual domestic sewage as research object. The experimental results showed that biological phosphorus removal could be inhibited by Ni2+,and when the mass concentration of Ni 2+increased from 0 mg/L to 10.0 mg/L,the removal rate of PO43--P decreased from 93% to 12%. The mechanism research results showed that:Ni2+could inhibit the anaerobic phosphorus release and aerobic phosphorus uptake by polyphosphate accumulating organisms and the synthesis of polyhydroxyalkanoates(PHA);When the mass concentration of Ni2+was 10.0 mg/L,the maximum amount of PHA(based on C mole number of PHA in a unit mass of volatiles) was only 2.4 mmol/g,which was much lower than that in the blank group. In addition,Ni2+could also affect the composition of microbial community and promote the proliferation of glycogen accumulating organisms in activated sludge.