Study On Treatment Of Landfill Leachate By Coagulation-Fenton Oxidation

Landfill leachate is a kind of complex toxic and harmful wastewater with high concentration of refractory organics.The existing treatment methods have some limitations,the treatment effect is not ideal and the treatment efficiency is low.In order to better solve the problem of landfill leachate,this study proposes a scheme of coagulation-Fenton oxidation combined treatment.Fenton advanced oxidation has outstanding treatment capacity for refractory organics and can effectively control water pollution.However,there are few cases of Fenton oxidation in the field of leachate.This study has great research significance and practical significance.In this study,the effect of coagulation pretreatment and Coagulation-Fenton combined treatment on the treatment efficiency of landfill leachate and its related factors are systematically investigated,and the operation parameters are optimized through single factor test and response surface analysis,so as to obtain the best working condition of the overall process for COD,turbidity and other water quality parameters control,and demonstrate the feasibility of combined treatment of landfill leachate.The main research contents and achievements are as follows:The optimum condition of coagulation treatment of landfill leachate is that the dosage of PAC is 100 mg/L,PAM is 10.0 mg/L,p H is 7.0.For simulated landfill leachate with initial COD of 800 mg/L and initial turbidity of 12.09 NTU,the removal rate of COD and turbidity is 42.50% and 87.26% respectively.For the actual landfill leachate with initial COD of 802mg/L and initial turbidity of 74.13 NTU,the removal rate of COD and turbidity is 21.45% and84.17% respectively.Furthermore,the effluent after coagulation is treated by Fenton oxidation,and the coagulation-Fenton oxidation process is investigated.For the simulated landfill leachate,the optimum condition of Fenton oxidation is that the dosage of H2SO4·7H2O is 0.0365 mol/L,H2O2 is 0.1740 mol/L,p H is 3.5.The removal rate of COD and turbidity can be increased to93.23% and 91.98%,respectively.For the actual landfill leachate,the optimum condition of Fenton oxidation is that the dosage of H2SO4·7H2O is 0.0477 mol/L,H2O2 is 0.2380 mol/L,p H is 3.0.The removal rate of COD and turbidity can be increased to 87.03% and 92.10%,respectively.In addition,the combined process has a very high removal rate for chroma and suspended solids,and a general removal capacity for ammonia nitrogen.Response surface analysis is carried out for the treatment of landfill leachate by the combination of coagulation and Fenton oxidation to optimize the parameters of the combined treatment process and carry out feasibility study.It is found that the combined process is more economical than the single Fenton oxidation process,more efficient than the traditional process,and has a stronger processing capacity,which has a huge application prospect.