Chen Jun, Ying Guang-Guo, Liu You-Sheng, Wei Xiao-Dong, Liu Shuang-Shuang, He Liang-Ying, Yang Yong-Qiang, Chen Fan-Rong
a State Key Laboratory of Organic Geochemistry, CAS Research Centre for Pearl River Delta Environmental Pollution and Control , Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou , China.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2017 Jul 3;52(8):804-818. doi: 10.1080/10934529.2017.1305181. Epub 2017 Apr 10.
This study aims to investigate nitrogen removal and its relationship with the nitrogen-cycle genes and microorganisms in the horizontal subsurface flow constructed wetlands (CWs) with different design parameters. Twelve mesocosm-scale CWs with four substrates and three hydraulic loading rates were set up in the outdoor. The result showed the CWs with zeolite as substrate and HLR of 20 cm/d were selected as the best choice for the TN and NH-N removal. It was found that the single-stage mesocosm-scale CWs were incapable to achieve high removals of TN and NH-N due to inefficient nitrification process in the systems. This was demonstrated by the lower abundance of the nitrification genes (AOA and AOB) than the denitrification genes (nirK and nirS), and the less diverse nitrification microorganisms than the denitrification microorganisms in the CWs. The results also show that microorganism community structure including nitrogen-cycle microorganisms in the constructed wetland systems was affected by the design parameters especially the substrate type. These findings show that nitrification is a limiting factor for the nitrogen removal by CWs.
本研究旨在调查不同设计参数的水平潜流人工湿地中氮的去除情况及其与氮循环基因和微生物的关系。在室外设置了12个中试规模的人工湿地，采用四种基质和三种水力负荷率。结果表明，以沸石为基质、水力负荷率为20 cm/d的人工湿地是去除总氮和氨氮的最佳选择。研究发现，由于系统中硝化过程效率低下，单级中试规模的人工湿地无法实现对总氮和氨氮的高效去除。人工湿地中硝化基因（氨氧化古菌和氨氧化细菌）的丰度低于反硝化基因（亚硝酸还原酶K和亚硝酸还原酶S），硝化微生物的多样性也低于反硝化微生物，这证明了上述观点。结果还表明，人工湿地系统中的微生物群落结构，包括氮循环微生物，受设计参数尤其是基质类型的影响。这些发现表明，硝化作用是人工湿地氮去除的限制因素。
