School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
Sci Total Environ. 2023 Jun 1;875:162692. doi: 10.1016/j.scitotenv.2023.162692. Epub 2023 Mar 8.
This study investigated the nitrogen removal enhanced by combined iron scraps and plant biomass, and its microbial response in the wetland with different plant ages and temperatures. The results showed that older plants benefitted the efficiency and stability of nitrogen removal, which could reach 1.97 ± 0.25 g m d in summer and 0.42 ± 0.12 g m d in winter. Plant age and temperature were the main factors determining the microbial community structure. Compared with temperature, plant ages affected more significantly on relative abundance of microorganisms such as Chloroflexi, Nitrospirae, Bacteroidetes and Cyanobacteria, and functional genera for nitrification (e.g., Nitrospira) and iron reduction (e.g., Geothrix). The absolute abundance of total bacterial 16S rRNA ranged from 5.22 × 10 to 2.63 × 10 copies g and presented extremely significant negative correlation to plant age, which would lead to a decline in microbial function on information storage and processing. The quantitative relationship further revealed that the ammonia removal was related to 16S rRNA and AOB amoA, while nitrate removal was controlled by 16S rRNA, narG, norB and AOA amoA jointly. These findings suggested that a mature wetland for nitrogen removal enhancement should focus on aging microbes caused by old plants and possible endogenous pollution.
本研究考察了铁屑和植物生物质联合增强湿地氮去除及其微生物响应，研究了不同植物年龄和温度条件下的湿地。结果表明，较老的植物有利于氮去除的效率和稳定性夏季可达到 1.97±0.25 g·m-2·d-1，冬季可达到 0.42±0.12 g·m-2·d-1。植物年龄和温度是决定微生物群落结构的主要因素。与温度相比，植物年龄对绿弯菌门、硝化螺旋菌门、拟杆菌门和蓝藻等微生物的相对丰度以及硝化（如硝化螺旋菌）和铁还原（如地杆菌）功能属的影响更为显著。总细菌 16S rRNA 的绝对丰度范围为 5.22×10至 2.63×10 拷贝 g-1，与植物年龄呈极显著负相关，这将导致微生物在信息存储和处理方面的功能下降。定量关系进一步表明，氨氮去除与 16S rRNA 和 AOB amoA 有关，而硝酸盐去除则由 16S rRNA、narG、norB 和 AOA amoA 共同控制。这些发现表明，为了增强氮去除，成熟的湿地应注重由老植物引起的老化微生物和可能的内源性污染。
