溶解氧对SBR脱氮性能与脱氮方式的影响

Impacts of dissolved oxygen level on nitrogen remval efficiencies and pathways in a sequential batch reactor

通过设置不同溶解氧(DO)浓度(曝气时段DO浓度均值分别为2.0、1.2和0.4 mg/L),研究了SBR的脱氮性能以及脱氮方式。结果表明,低DO条件下SBR可实现良好的脱氮效果,但需延长曝气时间。运行稳定后,各反应器氨氮的去除率均达到94%以上。总氮去除率随DO水平的降低而增高,分别为67%、74%和78%。不同DO浓度下SBR的脱氮方式不尽相同,DO浓度越低,同步硝化反硝化(SND)脱氮效果越明显。DO为2.0、1.2和0.4 mg/L时,SND率分别为31.4%、48.3%和66.8%。典型周期性实验表明,DO为2.0 mg/L时,通过SND现象去除的总氮占进水总氮的比例为7.6%,通过内源反硝化去除的总氮为12.0%;DO为1.2 mg/L时,通过亚硝酸型SND现象去除的总氮为12.2%,通过内源反硝化去除的总氮为8.1%;DO为0.4 mg/L时,通过亚硝酸型SND现象去除的总氮为15.8%,通过内源反硝化去除的总氮为5.0%。

The impacts of dissolved oxygen level on nitrogen removal efficiencies and pathways in a sequential batch reactor were studied by setting dissolved oxygen( DO) levels at 2. 0,1. 2 and 0. 4 mg / L,respectively. Results show that good nitrogen removal efficiencies were achieved even under low DO conditions. However,while low DO conditions required more aeration time. In addition,while the reactor was stably operated,ammonia removal efficiencies were over 94%. However,total nitrogen( TN) removal efficiency increased as DO level decreased. The TN removal efficiencies were 67%,74% and 78% at the applied DO levels. In addition,the phenomenon of simultaneous nitrification and denitrification( SND) was more obvious when low DO was applied.While the DO were 2. 0,1. 2 and 0. 4 mg / L,SND rates were 31. 4%,48. 3% and 66. 8%,respectively. Typical periodic experiments showed that while DO was 2. 0 mg / L,7. 6% of total nitrogen were removed via SND and12. 0% of total nitrogen were removal via endogenous denitrification. Moreover,while DO were 1. 2 mg / L and 0. 4mg / L,12. 2% and 15. 8% of total nitrogen were removed via nitrous acid type SND,respectively; 8. 1% and5. 0% of total nitrogen were removed via endogenous denitrification,respectively.