Wu Lingyan, Li Peng, Wang Guodong, Sijan Adib Hossain, Zhang Bo
School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
School of Municipal and Environmental Engineering, Lanzhou Jiaotong University, 88 Anning Road, Lanzhou, 730070, China.
J Environ Manage. 2025 Apr;380:125023. doi: 10.1016/j.jenvman.2025.125023. Epub 2025 Mar 22.
Rural wastewater treatment faces significant challenges in achieving stable effluent quality due to factors such as temperature fluctuations, variations in water quality and quantity, and low carbon-to-nitrogen (C/N) ratios. This study developed a full-scale, non-membrane, multi-stage anaerobic-anoxic-oxic (MSAO) biofilm reactor integrated with horizontal-vertical flow constructed wetlands (HVCWs), which was operated continuously for approximately 320 days with an average flow of 11.9 m/d in a rural area of northern China. Key parameters were optimized: hydraulic retention time (HRT) of 21-32 h, aeration rate of 4.0 m/h, carbon source dosing at 1.25 L/h, PAC dosing at 0.55 L/h, and mixed liquor reflux ratio at 200 %. The system demonstrated high removal efficiencies for COD (74.2 %), NH-N (93.4 %), TN (90.6 %), and TP (86.3 %), consistently meeting the class 1A of GB18918-2002, China (COD ≤50 mg/L, NH-N ≤ 5 mg/L, TN ≤ 15 mg/L, TP ≤ 0.5 mg/L), even under challenging conditions such as low C/N (3.3) and rainy seasons. More than 70 % of nitrogen and phosphorus were removed in the MSAO system. Microbial analysis revealed the enrichment of many functional bacteria. Proteobacteria play a key role in denitrification and phosphorus removal. Actinomycetes, Acidobacteria, and Firmicutes to nitrogen fixation and organic matter degradation. Nitrosomonas dominated ammonia oxidation, while Dechloromonas and Accumulibacter significantly contributed to phosphorus uptake. Seasonal variations in microbial diversity enabled consistent and highly efficient nutrient removal. The HVCWs system contributed 16.3 % of total phosphorus removal through selected plant species and phosphorus-absorbing modified ceramsite, ensuring effluent polishing and stability. With low operational costs ($0.12/m), the integrated system provides an effective and scalable solution for rural wastewater treatment, delivering high-quality effluent with minimal energy consumption.
由于温度波动、水质水量变化以及低碳氮比（C/N）等因素，农村污水处理在实现稳定出水水质方面面临重大挑战。本研究开发了一种全尺寸、无膜、多级厌氧-缺氧-好氧（MSAO）生物膜反应器，并与垂直-水平流人工湿地（HVCW）相结合，该系统在中国北方农村地区连续运行约320天，平均流量为11.9立方米/天。关键参数得到优化：水力停留时间（HRT）为21-32小时，曝气速率为4.0米/小时，碳源投加量为1.25升/小时，粉末活性炭（PAC）投加量为0.55升/小时，混合液回流比为200%。该系统对化学需氧量（COD）、氨氮（NH-N）、总氮（TN）和总磷（TP）表现出高去除效率，分别为74.2%、93.4%、90.6%和86.3%，即使在低C/N（3.3）和雨季等具有挑战性的条件下，也始终满足中国GB18918-2002一级A标准（COD≤50毫克/升，NH-N≤5毫克/升，TN≤15毫克/升，TP≤0.5毫克/升）。超过70%的氮和磷在MSAO系统中被去除。微生物分析显示许多功能细菌得以富集。变形菌门在反硝化和除磷中起关键作用。放线菌门、酸杆菌门和厚壁菌门参与固氮和有机物降解。亚硝化单胞菌主导氨氧化，而脱氯单胞菌和聚磷菌对磷吸收有显著贡献。微生物多样性的季节性变化使得营养物能够持续且高效地去除。HVCW系统通过选定的植物物种和吸磷改性陶粒对总磷去除贡献了16.3%，确保了出水的进一步净化和稳定性。该集成系统运行成本低（0.12美元/立方米），为农村污水处理提供了一种有效且可扩展的解决方案，以最低的能耗实现高质量出水。
