Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, MOE), School of Environmental Science and Technology, Dalian University of Technology, No.2 Linggong Road, Dalian 116024, PR China.
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, MOE), School of Environmental Science and Technology, Dalian University of Technology, No.2 Linggong Road, Dalian 116024, PR China.
Water Res. 2024 Apr 1;253:121296. doi: 10.1016/j.watres.2024.121296. Epub 2024 Feb 9.
Sulfur-driven autotrophic denitrification (SAD) exhibits significant benefits in treating low carbon/nitrogen wastewater. This study presents an eco-friendly, cost-effective, and highly efficient method for enhancing nitrogen removal performance. The addition of biochar prepared at 300 °C (BC300) notably increased nitrogen removal efficiency by 31.60 %. BC300 concurrently enhanced electron production, the activities of the electron transfer system, and electron acceptors. With BC300, the ratio of NADH/NAD rose 2.00±0.11 times compared to without biochar, and the expression of NAD(P)H dehydrogenase genes was markedly up-regulated. In the electron transfer system, BC300 improved the electroactivity of extracellular polymeric substances and the activities of NADH dehydrogenase and complex III in intracellular electron transfer. Subsequently, electrons were directed into denitrification enzymes, where the nar, nir, nor, and nos related genes were highly expressed with BC300 addition. Significantly, BC300 activated the Clp and quorum sensing systems, positively influencing numerous gene expressions and microbial communication. Furthermore, the O%, H%, molar O/C, and aromaticity index in biochar were identified as crucial bioavailable parameters for enhancing nitrogen removal in the SAD process. This study not only confirms the application potential of biochar in SAD, but also advances our comprehension of its underlying mechanisms.
硫自养反硝化（SAD）在处理低碳/氮废水中具有显著优势。本研究提出了一种环保、经济高效且高效的方法来增强脱氮性能。添加在 300°C 下制备的生物炭（BC300）可将氮去除效率显著提高 31.60%。BC300 同时增强了电子产生、电子传递系统和电子受体的活性。与没有生物炭相比，BC300 使 NADH/NAD 的比值增加了 2.00±0.11 倍，并且 NAD(P)H 脱氢酶基因的表达明显上调。在电子传递系统中，BC300 改善了细胞外聚合物的电活性以及细胞内电子传递中 NADH 脱氢酶和复合物 III 的活性。随后，电子被引导进入反硝化酶，其中添加 BC300 可使 nar、nir、nor 和 nos 相关基因高度表达。显著的是，BC300 激活了 Clp 和群体感应系统，对大量基因表达和微生物通讯产生积极影响。此外，生物炭中的 O%、H%、摩尔 O/C 和芳香度指数被确定为增强 SAD 过程中氮去除的关键生物可利用参数。本研究不仅证实了生物炭在 SAD 中的应用潜力，还增进了我们对其潜在机制的理解。
