Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, China.
Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, China.
Environ Sci Pollut Res Int. 2023 Nov;30(55):117624-117636. doi: 10.1007/s11356-023-30497-6. Epub 2023 Oct 23.
Lack of carbon source is the main limiting factor in the denitrification of low C/N ratio wastewater in the constructed wetlands (CWs). Agricultural waste has been considered as a supplementary carbon source but research is still limited. To solve this problem, ferric carbon (Fe-C) + zeolite, Fe-C + gravel, and gravel were used as substrates to build CWs in this experiment, aiming to investigate the effects of different carbon sources (rice straw, corncobs, alkali-heated corncobs) on nitrogen removal performance and microbial community structure in CWs for low C/N wastewater. The results demonstrated that the microbial community and effluent nitrogen concentration of CWs were mainly influenced by the carbon source rather than the substrate. Alkali-heated corncobs significantly enhanced the removal of NO-N, NH-N, NON, and TN. Carbon sources addition increased microbial diversity. Alkali-heated corncobs addition significantly increased the abundance of heterotrophic denitrifying bacteria (Proteobacteria and Bacteroidota). Furthermore, alkali-heated corncobs addition increased the copy number of nirS, nosZ, and nirK genes while greenhouse gas fluxes were lower than common corncobs. In summary, alkali-heated corncobs can be considered as an effective carbon source.
在人工湿地（CWs）中，缺乏碳源是低 C/N 比废水反硝化的主要限制因素。农业废弃物已被认为是一种补充碳源，但研究仍然有限。为了解决这个问题，本实验使用铁碳（Fe-C）+沸石、Fe-C+砾石和砾石作为基质来构建 CWs，旨在研究不同碳源（稻草、玉米芯、碱热玉米芯）对低 C/N 废水 CWs 中氮去除性能和微生物群落结构的影响。结果表明，CWs 的微生物群落和出水氮浓度主要受碳源而不是基质的影响。碱热玉米芯显著提高了 NO-N、NH-N、NON 和 TN 的去除率。碳源的添加增加了微生物的多样性。碱热玉米芯的添加显著增加了异养反硝化细菌（变形菌门和拟杆菌门）的丰度。此外，碱热玉米芯的添加增加了 nirS、nosZ 和 nirK 基因的拷贝数，而温室气体通量低于普通玉米芯。总之，碱热玉米芯可以作为一种有效的碳源。
