The Treatment Of Sulfamethoxazole Wastewater By UV-H₂O₂ And UV-Heterogeneous Fenton

Emerging Contaminates（ECs）are harmful to humans and the environment even at low concentrations.Sulfonamides（SAs）are a type of ECs with high detection frequency in the environment and its pollution problem has attracted people’s great attention.As the representative of SAs,Sulfonamides（SMX）has the characteristics of stronger toxicity and recalcitrance to biodegrade.Traditional sewage treatment process is difficult to treat,therefore,it is of positive significance to study an economical and effective degradation method for SMX.In this study,the progress of UV-H₂O₂ reaction,UV-heterogeneous Fenton reaction were used to degrade sulfamethoxazole wastewater.The research contents mainly include the following four aspects:1)study the optimization of the oxidative conditions of sulfamethoxazole（SMX）under UV-H₂O₂ conditions,and establish the apparent kinetic model for the oxidation of SMX under medium-wave ultraviolet and short-wave ultraviolet radiation conditions.2)compare the effect of three single metal-supported catalysts of Cu,Mn,and Co on the degradation of SMX in the UV-single-metal supported catalyst Fenton system,;3)optimized and evaluate Catalyst preparation conditions（bimetal molar ratio,calcination temperature and calcination time）,and analyze the appearance of the catalyst with the best activity and the presence of the metal 4)the optimization of the conditions of the UV-bimetallic supported catalyst Fenton oxidation sulfamethoxazole and preliminary discussion of its degradation mechanism and pathways.The following conclusions has been obtained through these research:（1）In the UVB-H₂O₂ system,when H₂O₂ dosage was 20.0 mmol/L,the initial concentral of SMX is 20mg/L the removal rate of SMX was 57.5%after 2.5h reaction.In the UVC-H₂0₂system,when the H₂O₂ dosage was 7.5 mmol/L,and the removal rate of SMX is 62.2%after1.5h reaction.The corresponding apparent kinetic equations for the two systems are:V=1.484×P^0.204×F^0.343和V=2.742×P^0.393×F^0.244;（2）The order of catalytic activity of Cu,Mn and Co metals in UV-single metal supported heterogenous Fenton system is:Cu>Co>Mn for UVB radiation,Cu>Mn>Co UVC radiation;（3）The optimum preparation conditions of zeolite-supported Cu/Mn bimetallic catalysts were as follows:the molar ratio of Cu and Mn in the impregnating solution was 2:1,the calcination temperature was 300°C,and the calcination time was 3h,which has good catalyst stability,and the activity decreased little after repeated use.Rarely,the metal component is supported on the surface of the carrier in a crystalline state,Cu mainly exists in the form of CuO,Cu₂O and Cu/Mn complex oxides,and Mn mainly exists in the form of Mn₃O₄;（5）In the UV-Cu/Mn-zeolite heterogeneous Fenton system,when the catalyst dosage is0.15g/L,the initial concentration of SMX is 20mg/L,the dosage of H₂O₂ is 7.5mmol/L,and the removal rate of SMX and COD is 77.3%and 43%respectively after 1.5h reaction,compared with UVC-H₂O₂ system,the removal rate increased by 15.1%and 7%correspondingly.And compared with UV-zeolite-loaded Cu heterogeneous Fenton system,the removal rate of SMX only increased by 1.9%,but decreased half dosage of catalyst.