Institute of Plant Nutrition, Resources and Environment, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
China-New Zealand Joint Laboratory of Water Environment Research, Beijing, 100097, China.
Environ Sci Pollut Res Int. 2023 Jun;30(28):72710-72720. doi: 10.1007/s11356-023-27557-2. Epub 2023 May 13.
This study investigated the effect of biochar on real domestic wastewater treatment by constructed wetlands (CWs). To evaluate the role of biochar as a substrate and electron transfer medium on nitrogen transformation, three treatments of CW microcosms were established: conventional substrate (T1), biochar substrate (T2), and biochar-mediated electron transfer (T3). Nitrogen removal increased from 74% in T1 to 77.4% in T2 and 82.1% in T3. Nitrate generation increased in T2 (up to 2 mg/L) but decreased in T3 (lower than 0.8 mg/L), and the nitrification genes (amoA, Hao, and nxrA) in T2 and T3 increased by 132-164% and 129-217%, respectively, compared with T1 (1.56 × 10- 2.34 × 10 copies/g). The nitrifying Nitrosomonas, denitrifying Dechloromonas, and denitrification genes (narL, nirK, norC, and nosZ) in the anode and cathode of T3 were significantly higher than those of the other treatments (increased by 60-fold, 35-fold, and 19-38%). The genus Geobacter, related to electron transfer, increased in T3 (by 48-fold), and stable voltage (150 mV) and power density (9 uW/m) were achieved. These results highlight the biochar-mediated enhancement of nitrogen removal in constructed wetlands via nitrification, denitrification, and electron transfer, and provide a promising approach for enhanced nitrogen removal by constructed wetland technology.
本研究通过人工湿地（CWs）考察了生物炭对实际生活污水的处理效果。为了评估生物炭作为基质和电子传递介质对氮转化的作用，建立了三种 CW 微宇宙处理方法：传统基质（T1）、生物炭基质（T2）和生物炭介导的电子传递（T3）。氮去除率从 T1 的 74%增加到 T2 的 77.4%和 T3 的 82.1%。T2 中硝酸盐生成增加（最高达 2mg/L），但 T3 中降低（低于 0.8mg/L），且 T2 和 T3 中的硝化基因（amoA、Hao 和 nxrA）分别比 T1 增加了 132-164%和 129-217%。T3 中阳极和阴极的硝化菌 Nitrosomonas、反硝化菌 Dechloromonas 和反硝化基因（narL、nirK、norC 和 nosZ）均显著高于其他处理（增加了 60 倍、35 倍和 19-38%）。与电子传递有关的地杆菌属（Geobacter）在 T3 中增加了 48 倍，并且实现了稳定的电压（150mV）和功率密度（9uW/m）。这些结果突出了生物炭通过硝化、反硝化和电子传递增强人工湿地氮去除的作用，为利用人工湿地技术增强氮去除提供了一种有前途的方法。
