供氧模式对SBR反应器内同步硝化反硝化的影响

在不同的供氧模式下,研究了SBR法处理低碳源城市污水同步硝化反硝化(SND)过程中DO、ORP和pH的变化规律.试验结果显示,在恒定气量连续曝气反应过程中,DO、ORP和pH曲线上均出现了预示SND结束而完全硝化过程开始的折点,且经由SND过程的TN去除率随曝气量降低而增加;在恒定气量具有不同曝气百分数(AF)的间歇曝气模式下,随AF降低,DO、ORP和pH曲线上不仅没有出现折点而且均呈现趋于平直、稳定的趋势,经由SND过程的TN去除率相应增加;在恒定DO浓度连续曝气的模式下,随DO浓度从2.0 mg/L降低至0.5 mg/L时,ORP和pH值的波动变化逐渐趋于稳定且SND的脱氮效率也随之增加.通过对以上三种供氧模式下的试验结果进行分析,得出具有低AF的间歇曝气和恒定、适宜、低DO浓度范围的连续曝气两种模式,不仅有利于低碳源城市污水SND过程的稳定,而且还可节省曝气量.

Effect of Oxygen Supply on Simultaneous Nitrification and Denitrification (SND) in Sequencing Batch Reactor (SBR)

The DO, ORP and pH profiles of SND treating low carbon municipal wastewater in SBR were investigated under different oxygen supply conditions. The results indicated that under the mode of continuous aeration (CA) with fixed air flux in a cycle, there are breakpoints in DO, ORP and pH profiles indicated the end of SND and the beginning of complete nitrification and TN removal rate via to SND increases with air flux decreasing. Under the mode of intermit tent aeration (IA) with different aeration fraction (AF) at fixed air flux in a cycle, the profiles of DO, ORP and pH pro files are tended to be the level and straight lines without any obviously breakpoints or pinpoints and TN removal rate due to SND increases with AF decreasing. Under the fixed DO concentration range, the variation of ORP and pH values are tended to be stable and TN removal rate increases from DO 2.0 ～ DO 0.5 mg/L. These results suggest that the modes of oxygen supply by IA with small AF and fixed the appropriate low DO concentration range both benefit SND and save oxy gen quantity.