Zn2+对SBR单级好氧模式生物除磷性能的影响

以合成废水为研究对象,以丙酸盐为单一外加碳源,通过比较进水中不同Zn2+浓度(0,1,5,10,20mg/L)下单级好氧模式下序批式反应器(SBR)的除磷效果,考察进水Zn2+浓度对单级好氧SBR生物除磷性能的影响,并通过分析各反应器中典型周期内磷及微生物体内储能物质的变化,探究Zn2+对单级好氧SBR生物除磷性能的影响机理.当进水Zn2+浓度为0和1mg/L时,除磷率分别高达96.84%和97.90%.当进水Zn2+浓度为5,10,20mg/L时,系统除磷率分别为89.32%,76.43%和57.29%,说明较高浓度Zn2+对单级好氧SBR生物除磷有抑制作用.结果表明,较高浓度Zn2+可抑制COD的降解,微生物体内聚羟基脂肪酸酯好氧合成及磷酸盐激酶活性,并促进GAOs的代谢,使聚磷合成和水解量减少,从而降低系统的除磷性能.

Effect of Zn2+ on biological phosphorus removal performance in single-stage oxic sequencing batch reactor

Effect of Zn2+ (0, 1, 5, 10 and 20mg/L) on phosphorus removal in single-stage oxic sequencing batch reactor (SBR) was investigated, the cyclic variations of phosphorus and intracellular polymers were analyzed, and the influencing mechanism of Zn2+ on phosphorus removal induced by the single-stage oxic regime was explored. The experimental results showed that 96.54% and 97.48% of the influent phosphorus could be removed in the reactors fed with 0and 1mg/L Zn2+. However, the phosphorus removal efficiency decreased to 89.20%, 76.43%, 57.29% respectively in the reactors fed with 5, 10and 20mg/L Zn2+, suggesting that a higher concentration of Zn2+ inhibited the phosphorus removal induced by the single-stage oxic regime. It was demonstrated that the effect of Zn2+ on phosphorus removal was due to the inhibition to the degradation of COD, synthesis and hydrolysis of polyhydroxyalkanoates and the activity of polyphosphate kinase. Moreover, the metabolic shift from polyphosphate accumulating organisms to glycogen accumulating organisms at high Zn2+ concentrations of could also decrease the phosphorus removal ability of the system.