氨氮的浓度对短程硝化的影响及其动力学研究

Study on the Effect and Kinetic of Ammonia Nitrogen Concentration on the Partial Nitrification

通过模拟A/O污水处理工艺,文章研究了不同的进水氨氮(NH4+-N)浓度下,实现亚硝态氮(NO2--N)稳定累积的过程和机理,并对其进行反应动力学分析。结果表明,反应器进水NH4+-N浓度从40 mg/L开始,100、200、400、600、800 mg/L,最终浓度提高到1000mg/L的梯度变化下,氨氧化速率的下降比率最高为36.4%、亚硝酸盐氧化速率的的下降比率最高为96.0%,对亚硝酸盐氧化菌活性抑制效果显著。1000 mg/L进水NH4+-N浓度下NO2--N累积速率随溶解氧(DO)升高而提高,DO超过4.5 mg/L时NO2--N累积速率接近最大值,但结合实际经济效益与工程实践考虑DO取3.0~3.5 mg/L之间实现短程硝化效果最佳。使用莫诺模型拟合氨氧化菌(AOB)动力学行为,进水NH4+-N浓度从40 mg/L提高到1000 mg/L,反应器最大NH4+-N比氧化速率由0.23 d-1上升到0.74 d-1,AOB利用底物更快。

The experiment was to explore the process and mechanism of nitrite nitrogen(NO2--N)stable accumulation under different influent ammonia nitrogen(NH4+-N)concentrations and analysis of reaction kinetics characteristics,by simulated A/O wastewater treatment process.The results showed that NH4+-N concentration in the reactor started from 40 mg/L,and increasing from 100 mg/L,200 mg/L,400 mg/L,600 mg/L,800 mg/L and final concentration to 1000 mg/L.The decline rate of ammonia oxidation rate was 36.4%at most,nitrite oxidation bacteria drop value max was 96.0%,and the activity inhibition effect was significant of NOB.The accumulation rate of NO2-N increased with the increase of dissolved oxygen(DO)at the concentration of NH4+-N in 1000 mg/L influent of inlet water.When DO exceeded 4.5 mg/L,the cumulative rate of NO2--N reached the highest considering the actual economic benefits and engineering,the partial nitrification reached the optimal effect when DO was between 3.0~3.5 mg/L.The Monod model was used to fit the behavior of AOB,the influent NH4+-N concentration increased from 40 mg/L to 1000 mg/L,and the maximum ammonia-nitrogen oxidation rate of the reactor increased from 0.23 d-1to 0.74 d-1,and AOB was more metabolically efficient.