氮负荷和上升流速对单级自养脱氮工艺的效能分析

Efficiency analysis on one-step autotrophic nitrogen removal by nitrogen loading and upflow velocity

采用单级自养脱氮EGSB反应器处理质量浓度约为100 mg/L的低氨氮废水,考察了氮负荷和上升流速对反应器脱氮性能的影响。结果表明,逐步缩短HRT至2.0 h,且同步提高污泥区DO至0.32~0.36 mg/L,成功将反应器的氮负荷从100 mg/(L·d)提升至1 200 mg/(L·d),NH_4^+-N、TN平均去除率分别为93.0%和76.6%。反应器适宜的DO随氮负荷的提升而升高,对曝气量和上升流速的调控可实现对污泥区DO的精准控制。此外,EGSB较高的上升流速有利于保有较高生物量,确保反应器在较高氮负荷条件下保持稳定的脱氮性能。

The one-step autotrophic nitrogen removal in EGSB reactor has been applied to the treatment of low ammonia nitrogen wastewater whose mass concentration is about 100 mg/L,and the influences of nitrogen loading and upflow velocity on denitrification capability in the reactor investigated.The results show that when HRT is shortened gradually to 2.0 h,and DO in sludge area is increased synchronously to 0.32-0.36 mg/L,the nitrogen loading of the reactor is successfully improved from 100 mg/（L·d）to 1 200 mg/（L·d）,and the average removing rates of NH4^＋-N and TN are 93.0% and 76.6%,respectively.The appropriate DO concentration for EGSB reactor increases with the increase of nitrogen loading.The regulation and control of aeration rate and upflow velocity could accurately control the DO in sludge area.In addition,relatively high upflow velocity of EGSB reactor is beneficial to maintain a relatively high biomass,so as to ensure that the reactor can keep stable denitrification capability,under relatively high nitrogen loading condition.