两级Fenton-BAF用于垃圾渗滤液深度处理工程

Application of Two-stage Fenton/BAF in Advanced Treatment of Landfill Leachate

垃圾渗滤液经过常规工艺处理后,COD和TN仍然很高,难以达到排放标准。垃圾渗滤液生化处理出水COD约为1 500 mg/L,TN约为400 mg/L,采用两级Fenton-曝气生物滤池(BAF)组合工艺对垃圾渗滤液生化处理出水进行深度处理。双氧水加药量按照与COD的质量比为1∶1来控制,硫酸亚铁的投加量按照与COD的质量比为2∶1来控制,Fenton反应pH值控制在3左右,单级Fenton的反应时间控制在10 h。BAF脱氮反应的进水碳氮比控制在4∶1左右,单级BAF的停留时间约为2 d。实际工程运行结果表明:该工艺运行稳定,出水水质好,对COD与TN的去除率分别为96%和95%,出水COD和TN分别为60 mg/L和20 mg/L,达到了《生活垃圾填埋场污染控制标准》(GB 16889—2008)的表2标准。

After conventional treatment, COD and TN concentrations in landfill leachate were still too high to meet the discharge limits. COD and TN in the biological treatment effluent were about 1 500 mg/L and 400 mg/L respectively. The combined process of two-stage Fenton/BAF was applied in the ad- vanced treatment of landfill leachate after biological treatment. The mass ratios of H202 to COD and fer- rous sulfate to COD were controlled at 1 ： 1 and 2 ： 1, pH of the Fenton oxidation reaction was 3, and the reaction time of each stage of Fenton oxidation was about 10 h. C/N ratio of the BAF influent was 4 ： 1, and hydraulic retention time of each stage of BAF was 2 d. The operation results showed that the combined process was stable and the effluent was good. The removal rates of COD and TN were 96% and 95% respectively. COD and TN concentrations in the effluent were 60 mg/L and 20 mg/L respectively. The effluent met the table 2 criteria specified in Standard for Pollution Control on the mestic Waste （ GB 16889 - 2008 ）.