基于包埋填料的短程硝化反硝化工艺的脱氮性能优化

Performance optimization of partial nitrification and denitrification based on immobilized fillers

为优化短程硝化反硝化工艺对模拟城市污水的脱氮处理性能,通过包埋固定化技术分别制得短程硝化、反硝化填料,形成连续流脱氮工艺。结果表明,短程硝化填料活性恢复后的氨氧化速率(AOR)可达39.83mg·(L·h)-1,亚硝酸盐积累率(NAR)稳定在96.60%。采用响应曲面法考察了短程硝化过程中的DO、HRT和填充率等因素对氨氮去除率(ARR)和NAR的影响,并建立了二次回归模型,通过模型预测的最佳运行工况为:HRT为3.48 h,DO为3.64 mg·L^(-1),填充率为20%。此时,后置反硝化包埋填料,当平均C/N为2.82时,总氮出水平均质量浓度为2.29 mg·L^(-1),去除率稳定在94.27%,说明该工艺对城市污水具有良好的脱氮性能。高通量测序结果表明,短程硝化和反硝化包埋填料内部的功能菌均有大量增殖,并始终保持着优势地位。

In order to optimize the performance of partial nitrification and denitrification on nitrogen removal in simulated municipal wastewater treatment,partial nitrification and denitrification fillers were prepared by the immobilization technology,and a continuous flow nitrogen removal process was realized.The results showed that the ammonia oxidation rate(AOR) of the partial nitrification immobilized fillers after activity recovery could reach 39.06 mg·(L·h)-1,and the nitrite accumulation rate(NAR) maintained at about 96.60%.The response surface methodology(RSM) was used to investigate the effects of DO,HRT and filling rate in the partial nitrification process of immobilized fillers on the ammonia nitrogen removal rate(ARR) and NAR,and a quadratic regression model was established to predict the best operating conditions:HRT of 3.48 h,DO of 3.64mg·L^(-1),the filling rate of 20%.Under these conditions,the post-denitrification immobilized fillers were installed,the average mass concentration of total nitrogen(TN) in the effluent was 2.29 mg·L^(-1) with a stable removal rate of 94.27% when the average C/N was 2.82.This indicates that the process had a good nitrogen removal performance from municipal wastewater.The results of high-throughput sequencing showed that the functional bacteria in the partial nitrification and denitrification immobilized fillers largely proliferated and always maintained dominance.