Abstract:

Landfill leachate was treated by A/O-coagulation-BDD combined processes, and the operation parameters were optimized. The optimal HRT and sludge recirculation ratio was 10.7 days and 3.5 for A/O treatment process. Reaction pH and optimal dose of ferric chloride coagulation treatment was 5.5 and 0.4 g/L. The current density and A/V ratio (anode area/reaction volum) for best performance of BDD was 60 mA/cm² and 4 m^-1. COD_Cr concentration in raw leachte and final effluent were 13375 mg/L and 60 mg/L, with the removal efficiency of 99.5%. TOC concentration before and after treatment by combined treatment process were 6893 mg/L and 12 mg/L, with the removal efficiency of 99.8%. Ammonia nitrogen was completely removed by the combined treatment processes from 1889 mg/L to 0 mg/L. The contribution of A/O, coagulation, and BDD was 59.0%, 32.9%, and 7.6% for COD_Cr removal of total COD_Cr, was 50.5%, 46.1%, and 13.2% for TOC removal, was 84.3%, 2.5%, and 3.2% for ammonia nitrogen removal, respectively.

Key words: landfill leachate, A/O, coagulation, BDD, organic matter, ammonia nitrogen

摘要：

研究组合工艺“A/O-混凝-BDD”对垃圾渗滤液中有机物和氨氮的处理效果, 优化各段工艺的运行参数。结果表明, 各工艺最佳运行条件: A/O 工艺水力停留时间(HRT)为 10.7 d, 回流比为3.5; 混凝剂工艺氯 化铁为混凝剂, pH=5.5, 添加量为0.4 g/L; BDD工艺电流密度为60 mA/cm², 电极面积/反应体积为4 m^-1。最佳工艺条件下进、出水 COD_Cr 平均浓度分别为 13375 和60 mg/L, 去除率为99.5%; 进、出水 TOC 平均浓度分别为 6893 和 12 mg/L, 去除率为 99.8%。进、出水氨氮平均浓度分别为 1889 和 0 mg/L, 去除率为100.0%。A/O、混凝和 BDD 对 COD_Cr 去除贡献分别为 59.0%, 32.9%和 7.6%, 对 TOC 去除贡献分别为50.5%, 46.1%和13.2%, 对氨氮去除贡献分别为84.3%, 2.5%和3.2%。

关键词: 垃圾渗滤液, A/O, 混凝, BDD, 有机质, 氨氮