多级垂直潮汐流人工湿地厌氧氨氧化脱氮研究

Study on Nitrogen Removal by Anaerobic Ammonium Oxidation in Multi-stage Vertical Tidal Flow Constructed Wetlands

采用多级垂直潮汐流人工湿地(MVTF-CWs)处理城市污水处理厂剩余活性污泥厌氧消化液(EAS-ADL),在低C/N条件下,研究MVTF-CWs对典型污染物的去除特征及其厌氧氨氧化脱氮行为,并利用FISH和高通量测序方法分析主要功能微生物。结果表明,在原水COD/ρ(TN)为0.46的条件下,进水NH4+^-N、TN的质量浓度分别为(1 002±71)、(1 003±71)mg/L,平均去除率分别为98.97%和62.64%;进水COD为(456.4±57.7)mg/L,平均去除率为93.22%。MVTF-CWs中第3和第5级对TN的去除贡献最大。第3和第5级湿地单元中存在Anammox菌,相对丰度分别为7.77%和12.14%,而异养反硝化菌占比仅为2.22%和0.22%,表明第3和第5级湿地单元高TN去除主要通过厌氧氨氧化脱氮途径实现。

A multi-stage vertical tidal flow constructed wetlands(MVTF-CWs)has been applied to the treatment of the excess activated sludge anaerobic digestive liquids(EAS-ADL)in a municipal wastewater treatment plant.The characteristics of typical pollutant removal by MVTF-CWs and the nitrogen removal by anaerobic ammonium oxidation were researched under low C/N ratio condition.Furthermore,dominant functional microbial were analyzed by FISH and high-throughput sequencing.The results showed that when the COD/ρ(TN)of raw water was 0.46,the influent mass concentrations of NH4+-N and TN were(1 002±71)and(1 003±71)mg/L,the average removal rates of NH4+-N and TN were 98.97%,62.64%.In addition,the COD of influent was(456.4±57.7)mg/L,and its removal rate was 93.22%.The third and fifth stages contributed the most to the removal of TN in MVTF-CWs.Anammox bacteria existed in the third and fifth wetland stages,the relative abundances of Anammox in the third and fifth wetland units were 7.77%and 12.14%,whereas heterotrophic denitrifying bacteria accounted for merely 2.22%and 0.22%.It was indicated that the high TN removal in the third and fifth wetland units was mainly achieved by anaerobic ammonium oxidation pathway.