淀粉/聚乙烯醇固体碳源对污水厂尾水的脱氮效果

Effect of Starch/Polyvinyl Alcohol Solid Carbon Sources on Nitrogen Removal of Tail Water from Municipal Wastewater Treatment Plant

针对市政污水厂尾水中普遍存在碳源不足的问题,以低碳氮比水体为研究对象,探究了固体碳源填料柱在不同HRT下的脱氮效果。结果表明,在启动运行20 d后,反应器中载体上的生物膜逐渐成熟,出水水质稳定。当反应器HRT=4 h时,脱氮率保持在90%以上,出水COD保持在40 mg/L以下,且没有NO_(2)^(-)-N积累。同时,反应器出水中检测到了NH_(4)^(+)-N,这表明可能存在硝酸盐异化还原为铵盐(DNRA)的过程。在微生物作用和物理浸出过程中,固体碳源有机碳的释放分别占总碳释放量的81.74%和18.26%,表明碳释放主要是由微生物作用引起的。高通量测序分析结果显示,相对丰度较高的菌属主要有Thauera、Zoogloea、Cloacibacterium、Macellibacteroides等,同时检测出了Desulfovibrio,这可能与出水中检测到NH4+-N有关。

This paper investigated the effect of solid carbon sources packed columns on nitrogen removal from low carbon to nitrogen ratio wastewater under different hydraulic retention times(HRT),so as to solve the problem of insufficient carbon sources in tail water from municipal wastewater treatment plants(WWTPs).After 20 days of operation,the biofilm on the packing media gradually matured and the effluent quality was stable.When the HRT was 4 hours,the nitrogen removal rate remained above 90%,the effluent COD was always below 40 mg/L,and no accumulation of NO_(2)^(-)-N was observed.In addition,NH_(4)^(+)-N was detected in the effluent from the reactor,indicating that there might be a process of dissimilatory nitrate reduction to ammonia(DNRA).In the process of microbial action and physical leaching,the release of organic carbon from solid carbon sources accounted for 81.74%and 18.26%of the total carbon release,respectively,indicating that the main reason of carbon release was caused by microbial action.The high⁃throughput sequencing results showed that the genera such as Thauera,Zoogloea,Cloacibacterium and Macellibacteroides were the predominant bacteria with high relative abundance.In addition,Desulfovibrio was detected in the reactor,which might be related to the detection of NH_(4)^(+)-N in the effluent.