Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China.
Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
Water Environ Res. 2019 Nov;91(11):1498-1508. doi: 10.1002/wer.1147. Epub 2019 Jun 2.
In order to strengthen in situ nitrogen removal of urban landscape water, a novel pilot-scale tubular bioreactor-enhanced floating treatment wetland (TB-EFTW) was constructed, and the long-term performance and responsible microbial mechanisms were investigated in this study. The results showed that the system could remove 81.5% nitrogen from the landscape water after 240 days' operation. Moreover, the contribution rate of plant absorption to nitrogen was low (8.3%), which indicated that microbial biotransformation rather than plant absorption played a more key role in nitrogen removal in TB-EFTW system. The declining dissolved oxygen (DO) concentration along the axial direction of tubular bioreactor (TB) resulted in the sequential bacterial community of nitrifying, aerobic denitrifying, and anoxic denitrifying bacteria in the front, middle, and final part of TB. High-throughput sequencing results demonstrated that the internal environment of the system realized the coexistence of nitrifying, aerobic denitrifying and anoxic denitrifying process. The reason was mainly because that oxic-anoxic (O-A) areas were formed in sequence along the axial direction of tubular bioreactor. Overall, a unique advantage in nitrogen removal was achieved in TB-EFTW, which could provide important references for in situ treatment of urban landscape water. PRACTITIONER POINTS: TB-EFTW strengthened nitrogen removal for in situ urban landscape water treatment. Microbial conversion played a key role in nitrogen removal of the TB-EFTW system. The unique distribution of oxic-anoxic (O-A) areas was formed in sequence along the TB. Nitrification, aerobic, and anoxic denitrification were synergistically involved in the TB.
为了强化城市景观水的原位脱氮，本研究构建了一种新型中试规模的管状生物反应器增强型浮岛湿地（TB-EFTW），并对其长期性能和相关微生物机制进行了研究。结果表明，该系统在 240 天的运行后可去除景观水中 81.5%的氮。此外，植物吸收对氮的贡献率较低（8.3%），这表明在 TB-EFTW 系统中，微生物转化而非植物吸收在氮去除中发挥了更关键的作用。随着溶解氧（DO）浓度沿管状生物反应器（TB）轴向的下降，在 TB 的前段、中段和后段依次出现了硝化细菌、好氧反硝化细菌和缺氧反硝化细菌。高通量测序结果表明，系统的内部环境实现了硝化、好氧反硝化和缺氧反硝化过程的共存。其主要原因是沿 TB 轴向依次形成了好氧-缺氧（O-A）区。总体而言，TB-EFTW 在强化城市景观水原位处理方面具有独特的优势，可为城市景观水的原位处理提供重要参考。
TB-EFTW 强化了城市景观水的原位脱氮。
微生物转化在 TB-EFTW 系统的氮去除中起着关键作用。
沿 TB 依次形成独特的好氧-缺氧（O-A）区分布。
硝化、好氧和缺氧反硝化协同参与了 TB 过程。
