混凝-异相Fenton工艺处理渗沥液纳滤浓缩液研究

Study on leachate nanofiltration concentrate treated by a coagulation-heterogeneous fenton process

通过混凝-异相Fenton组合工艺对高有机物含量的垃圾渗沥液纳滤浓缩液进行试验研究.考察不同处理工况对纳滤浓缩液有机物去除效果的影响.并通过正交试验得出组合工艺的最优工况,分析最优工况下出水达标的可行性.对组合工艺在反应过程中溶解性有机质及氮污染物含量的变化情况进行探讨.并分析了组合工艺的药剂投加成本.结果表明:组合工艺对COD去除的最优处理工况为:PFS投加量为6g/L,混凝初始pH值为7,PAM投加量为25mg/L、H_(2)O_(2)与COD质量比为10,Fenton反应初始pH值为4,催化剂与COD质量比为16.在最优工况下COD去除率为98.62%.经组合工艺处理后出水水质可实现达标排放.在反应过程中,混凝单元能够降低异相Fenton单元的处理负荷并保证了组合工艺出水中TN和NH_(4)^(+)-N的达标排放,组合工艺对浓缩液中HA、FA与TON的去除率分别为93.54%、86.80%与83.98%.异相Fenton单元对混凝过程中去除效果稍差的HyI进一步氧化分解而实现COD出水达标,其去除率为86.02%.在最优工况下组合工艺的药剂投加成本为47.10元/t.

An experimental study on the landfill leachate nanofiltration concentrate with a high organic content was performed using a coagulation-heterogeneous Fenton combined process.The effect of different treatment conditions on the removal of organic matter from nanofiltration concentrate was investigated.The working conditions of the combined process were optimized through the orthogonal test, and the feasibility of the effluent reaching the standard under the optimal working conditions was analyzed.The changes in dissolved organic matter and nitrogen pollutant content in the reaction process of the combined process were discussed.The cost of adding chemicals for the combined process was also elaborated.The results show that the optimal treatment conditions of the combined process for COD removal are: the dosage of PFS is 6g/L, the initial pH of coagulation is 7, the dosage of PAM is 25mg/L.The mass ratio of H_(2)O_(2)to COD is 10, the initial pH of the Fenton reaction is 4, and the mass ratio of catalyst to COD is 16,reaching a COD removal rate of 98.62% under the optimal conditions.After the combined process treatment, the quality of the effluent can be discharged according to the related standard.In the reaction process, the coagulation and sedimentation units can reduce the processing load of the heterogeneous Fenton unit and ensure the discharge of TN and NH_(4)^(+)-N in the effluent of the combined process.The removal rate of HA, FA, and TON from the concentrate is 93.54, 86.80, and 83.98%, respectively.The heterogeneous Fenton unit further oxidizes and decomposes HyI, exhibiting a slightly poor removal effect during the coagulation process, to achieve the COD effluent standard, and its removal rate is 86.02%.Under optimal working conditions, the cost of adding chemicals for the combined process is 47.10yuan/t.