混凝沉淀-吹脱-Fenton氧化协同预处理垃圾渗滤液膜滤浓缩液的研究

目的]研究化学混凝沉淀-吹脱-Fenton氧化法对垃圾渗滤液膜滤浓缩液的处理效果。方法]以上海某填埋场生活垃圾渗滤液膜滤浓缩液为研究对象,研究混凝沉淀-吹脱-Fenton氧化协同处理工艺对有机物和NH3-N的去除,考察混凝剂种类、投加量、吹脱温度、空气流量、吹脱pH和H2O2浓度、Fe2＋浓度、氧化pH和时间等因素的影响。结果]混凝沉淀中,添加6 g/L MgO和2 g/L Ca（OH）2混凝沉淀效果最佳。最佳吹脱试验条件确定为pH 11.0～11.5,温度≥30℃,吹脱时间为4.5～5.0 h,空气流量为6 L/（min.L）,吹脱效率大于80%。Fenton氧化的最优化条件为H2O2 750 mmol/L,Fe2＋28 mmol/L,反应时间45 min,pH 3。整个工艺对COD去除率达93.4%,对NH3-N去除率达95.7%。结论]化学混凝沉淀-吹脱-Fenton氧化法对垃圾渗滤液膜滤浓缩液的处理效果较好,值得进一步研究。

Treatment of Concentrated Leachate from RO System Using Coagulation, Ammonia Stripping and Fenton Oxidation Processes

Objective]The research aimed to study the control of concentrated leachate with method of coagulation,ammonia stripping and Fenton oxidation processes.Method]A treatment process for the concentrated landfill leachate from a reverse osmosis equipment using coagulation,ammonia stripping and Fenton oxidation was developed.The effects of the composite coagulants,ammonia stripping temperature,pH,quantity of flow air,H2O2 and Fe2+ concentrations on COD and NH3-N removals were investigated.Result]The results showed that the optimum efficiency of coagulation and ammonia stripping could be achieved under the profiles of 6 g/L MgO and 2 g/L Ca(OH)2 by agitating for 24 h followed by blowing air at the speed of 6 L/(min·L) for 4.5-5.0 h at pH of 11.0-11.5.The optimistic conditions of orthogonal tests were H2O2 concentration 750 mmol/L,Fe2+ concentration 28 mmol/L,reaction time 45 min,pH 3.COD and NH3-N removal rates were 93.4% and 95.7% through the whole process.Conclusion]This research indicated that the control of concentrated leachate with method of coagulation,ammonia stripping and Fenton oxidation processes was ideal and should be studied for next step.