硝酸盐对磷酸盐还原系统除磷效能的影响

通过改变进水硝酸盐浓度，考察了硝酸盐对缺氧和好氧两种不同氧环境下的磷酸盐还原系统除磷效能的影响。试验结果表明，硝酸盐对两种氧环境下磷酸盐还原系统的除磷效能影响显著。当进水硝酸盐浓度为105～160mg／L时有利于缺氧条件下的磷酸盐还原。而进水硝酸盐对好氧条件下的磷酸盐还原产生显著抑制作用，并且两者存在显著的负相关（R^2=0.9827）。这种差异主要是由于两种不同氧环境下，硝酸盐对微环境构造的影响不同而造成的。同时，不同浓度的进水硝酸盐还会影响反应器内的PH值，进而影响磷酸盐还原进程。结果表明，偏碱性（pH8左右）有利于两种氧环境下的磷酸盐还原。

Effect of Influent Nitrate on Phosphorus Removal Efficiency of Phosphate Reduction System

The influence of influent nitrate on phosphorus removal efficiency of phosphate reduction systems under anoxic and aerobic condition was studied by changing the concentration of influent nitrate. It was shown that nitrate had significant influence on phosphorus removal efficiency of phosphate reduction system under anoxic and aerobic condition. When influent nitrate concentration was between 105 mg/L and 160 mg/L, it was favorable to anoxic phosphate reduction. However, influent nitrate had a remarkable inhibition on aerobic phosphate reduction, and there was a significant negative correlation between them (R~2 =0. 982 7). The difference on phosphorus removal efficiency was mainly due to different influence of nitrate on microenvironment structure under various oxygen environments. Moreover, different concentrations of influent nitrate also affected the pH value in the reactor, which can affect phosphate reduction process. It was found that slight alkaline (pH around 8) was favorable for phosphate reduction under anoxic and aerobic condition.