Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
Sci Total Environ. 2022 Aug 25;836:155728. doi: 10.1016/j.scitotenv.2022.155728. Epub 2022 May 4.
To improve the nitrogen removal (NR) capability of tidal flow constructed wetlands (TFCWs) for treatment of saline wastewater, biochar, produced from Cyperus alternifolius, was used to adsorb and immobilize a salt tolerant aerobic denitrifying bacteria (Zobellella sp. A63), and then was added as a substrate into the systems. Under low (2:1) or high (6:1) C/N ratio, the removal of NO-N and total nitrogen (TN) in the biochar immobilized bacteria (BIB) dosing system (TFCW3) was significantly higher (q < 0.05) than that in the untreated system (TFCW1) and the biochar dosing system (TFCW2). At low C/N ratio, the removal rates of NO-N, TN and chemical oxygen demand (COD) of TFCW3 were 68.2%, 72.6% and 82.5%, respectively, 15-20% higher than TFCW1 and 5-10% higher than TFCW2. When C/N ratio was further increased to 6, the pollutant removal rate of each system was greatly improved, but the removal rate of TFCW3 for NO-N/TN was still nearly 10% and 5% higher than TFCW1 and TFCW2, respectively. Microbial community analysis showed that aerobic denitrifying bacteria, sulfate reducing bacteria and sulfur-driven denitrifiers (DNSOB) played the most important role of NR in TFCWs. Moreover, biochar bacterial agent significantly increased the abundances of genes involved in NR. The total copy numbers of bacterial 16S rRNA, nirS, nirK, drsA and drsB genes in the TFCW3 were 1.1- to 3.76-fold higher than those in the TFCW1; Especially at low C/N ratio, the copy number of drsA and drsB in the upper layer of TFCW3 were 85.5 and 455 times that of TFCW1, respectively. Thus, BIB provide a more feasible and effective amendment for constructed wetlands to improve the N removal of the saline wastewater by enhancing the microbial NR capacity mainly via aerobic and sulfur autotrophic denitrification.
为了提高潮汐流人工湿地（TFCWs）处理含盐废水的脱氮（NR）能力，使用从香蒲中制备的生物炭吸附和固定耐盐好氧反硝化细菌（Zobellella sp. A63），然后将其作为基质添加到系统中。在低（2:1）或高（6:1）C/N 比下，生物炭固定细菌（BIB）投加系统（TFCW3）中 NO-N 和总氮（TN）的去除率明显高于未处理系统（TFCW1）和生物炭投加系统（TFCW2）（q < 0.05）。在低 C/N 比下，TFCW3 的 NO-N、TN 和化学需氧量（COD）去除率分别为 68.2%、72.6%和 82.5%，比 TFCW1 高 15-20%，比 TFCW2 高 5-10%。当 C/N 比进一步增加到 6 时，每个系统的污染物去除率都有了很大的提高，但 TFCW3 对 NO-N/TN 的去除率仍比 TFCW1 和 TFCW2 分别高近 10%和 5%。微生物群落分析表明，好氧反硝化菌、硫酸盐还原菌和硫驱动反硝化菌（DNSOB）在 TFCWs 中对 NR 起着最重要的作用。此外，生物炭细菌剂显著增加了 NR 相关基因的丰度。TFCW3 中细菌 16S rRNA、nirS、nirK、drsA 和 drsB 基因的总拷贝数比 TFCW1 高 1.1-3.76 倍；特别是在低 C/N 比下，TFCW3 上层的 drsA 和 drsB 拷贝数分别比 TFCW1 高 85.5 和 455 倍。因此，BIB 通过增强微生物 NR 能力，主要通过好氧和硫自养反硝化，为人工湿地提供了一种更可行和有效的改良方法，以提高含盐废水的脱氮效果。
