供氧分区对氧化沟系统脱氮效果的影响研究

Nitrogen removal performance under different partition aeration modes in oxidation ditch

针对传统氧化沟供氧分区调控困难,能耗高等问题,建立模拟氧化沟装置,研究好氧分段个数分别为1、2、4、7四种工况条件下氧化沟系统的脱氮性能。结果表明,在好氧区与缺氧区比例为1∶1的条件下,各分区供氧工况均具有较好的硝化效果,氨氮去除率均平均达到97%以上。供氧分区数量越少,好氧和缺氧区域越集中,反硝化作用的效果越好,TN去除效率越高,TN浓度由供氧分区数量最多的(13.25±1)mg/L降低至(3.15±1)mg/L。基于物料衡算,分析计算不同供氧分区条件下碳源的利用途径,结果表明功能区分布集中的供氧模式条件下碳源的脱氮利用率更高。利用高通量测序的方法,分析不同供氧分区条件下的微生物活性与种群差异,结果表明好氧区和缺氧区分区数量越少,反硝化细菌的活性与丰度越高。集中设置氧化沟内部的供氧区可促进系统内反硝化细菌的富集,进而提升氧化沟系统的脱氮性能。

In order to solve the difficulties of aeration partition regulation and high energy consumption in traditional oxidation ditch,an oxidation ditch device was simulated.The nitrogen removal performance of four aeration modes,which involving 1,2,4 and 7 aeration zones,respectively,were investigated.The results showed that under the same aeration area and aeration volume,the four aeration modes had good nitrification effect,and the ammonia nitrogen removal rate averaged over 97%.Better performance ofdenitrification and total nitrogen removal was achieved when aeration section gathered,TN concentration decreased from(13.25±1)mg/L to(3.15±1)mg/L.The results based on the material balance and utilizing the carbon source analysis under different aeration modes demonstrated that the carbon source was more effectively used for denitrification under multiple aeration modes.High-throughput sequencing analysis was used to study the microbial activity and population differences in different aeration modes.The results showed that the higher denitrifying bacteria activity and the more favorable was the enrichment of denitrifying bacteria when in gathering aeration section.With the decrease of the anoxic area,the average abundance of denitrifying bacteria was increasing.