连续曝气模式下同步硝化反硝化的持续稳定性

为研究反应周期内同步硝化反硝化(SND)过程的持续稳定性,试验以模拟城市污水为研究对象,于恒定气量连续曝气的SBR反应器内,在反应周期内恒定不同曝气量的条件下,考察氮转化规律和DO、ORP及pH的变化规律。结果表明,SND持续稳定的时间和TN去除率随曝气量的增加而减少和降低,DO、ORP和pH曲线上出现的折点可预示SND过程的结束和完全硝化反应的开始,而pH曲线上的"谷点"可预示硝化反应的结束。由此可知,在恒定气量连续曝气模式下,SND的持续稳定时间是有限的,不能延续到反应周期结束,但可用DO、ORP和pH值作为SND过程持续稳定程度的控制参数。

Sustained Stability of Simultaneous Nitrification and Denitrification in the Mode of Continuous Aeration with Fixed Air Flux

To study the sustained stability of simultaneous nitrification and denitrification(SND),the profiles of TN,NO3--N,NH3-N,NO2--N,DO,ORP and pH were examined in a SBR operating on the mode of continuous aeration(CA) and treating synthetic wastewater under the different fixed air flux during a cycle.It was found that TN removal efficiency reduced and sustained stable time of SND was shortened with increasing of air flux during CA cycle.Appearance of breakpoints in DO,ORP and pH profiles indicated the end of SND and beginning of complete nitrification,but the valley points in pH profile indicated the end of nitrification.Results suggested that duration of SND under the fixed air flux during CA were limited and cannot extend to the final of reaction,but the profiles of DO,ORP and pH can control the sustained stable SND.