Wang Kanming, Ye Qiaoqiao, Shen Yuxiang, Wang Yajing, Hong Qiankun, Zhang Chenlong, Liu Min, Wang Hongyu
College of Architecture and Environment, Sichuan University, Chengdu 610000, China.
College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
Membranes (Basel). 2023 Feb 4;13(2):194. doi: 10.3390/membranes13020194.
Membrane bioreactors (MBRs) are frequently used to treat municipal wastewater, but membrane fouling is still the main weakness of this technology. Additionally, the low carbon-nitrogen (C/N) ratio influent has been shown to not only increase the membrane fouling, but also introduce challenges to meet the effluent discharge standard for nitrogen removal. Herein, the authors addressed the challenges by adding cost-effective biochar. The results suggested that the biochar addition can enable membrane fouling alleviation and nitrogen removal improvement. The reduced membrane fouling can be ascribed to the biochar adsorption capacity, which facilitates to form bigger flocs with carbon skeleton in biochar as a core. As a result, the biochar addition significantly altered the mixed liquor suspension with soluble microbial product (SMP) concentration reduction of approximately 14%, lower SMP protein/polysaccharide ratio from 0.28 ± 0.02 to 0.22 ± 0.03, smaller SMP molecular weight and bigger sludge particle size from 67.68 ± 6.9 μm to 113.47 ± 4.8 μm. The nitrogen removal is also dramatically improved after biochar addition, which can be due to the initial carbon source release from biochar, and formation of aerobic-anaerobic microstructures. Microbial diversity analysis results suggested more accumulation of denitrification microbes including and . Less relative abundance of after biochar addition suggested less extracellular polymer substance (EPS) secretion and lower membrane fouling rate.
膜生物反应器（MBR）常用于处理城市污水，但膜污染仍是该技术的主要弱点。此外，进水的低碳氮（C/N）比不仅会增加膜污染，还会给达到氮去除的出水排放标准带来挑战。在此，作者通过添加具有成本效益的生物炭来应对这些挑战。结果表明，添加生物炭可以减轻膜污染并提高氮去除率。膜污染的减轻可归因于生物炭的吸附能力，这有助于以生物炭中的碳骨架为核心形成更大的絮凝物。结果，添加生物炭显著改变了混合液悬浮液，可溶性微生物产物（SMP）浓度降低了约14%，SMP蛋白质/多糖比从0.28±0.02降至0.22±0.03，SMP分子量减小，污泥粒径从67.68±6.9μm增大至113.47±4.8μm。添加生物炭后氮去除也显著改善，这可能是由于生物炭释放的初始碳源以及好氧-厌氧微结构的形成。微生物多样性分析结果表明，包括[具体微生物名称1]和[具体微生物名称2]在内的反硝化微生物积累更多。添加生物炭后[具体微生物名称3]的相对丰度降低，表明细胞外聚合物物质（EPS）分泌减少且膜污染速率降低。
