Study The Degradation Of Organic Pollutants Through Peroxymonsulfate Activated By Composited Metallic Oxides And Sulfides

In recent years,the dosage of Pharmaceutical and personal care products（PPCPs）have been increased as the acceleration of urbanization.They may display the risk to the life due to PPCPs introduction into the environment by sewage.In this paper,the performance and various influencing parameters of composited metallic oxides and sulfides in PMS system,which were explored in terms of typical anti-inflammatory drug diclofenac sodium（DCF）.Based on the results,a possible mechanism and intermediates of degradation in composite metallic sulfide/PMS system were proposed.The research contents and conclusions are as follows:（1）The effects of CuFe2O4 synthesis methods,g-C3N4 precursors and composite methods of CuFe2O4@g-C3N4 on DCF degradation efficiency were investigated.The results show that CuFe2O4（SO）@g-C3N4（M）（HL）has better catalytic and can completely degrade DCF within45 min.Calcination temperature of g-C3N4 and the mass ratio of CuFe2O4 in CuFe2O4@g-C3N4have great impact on the activation of PMS.The composite material obtained of g-C3N4 at 550℃of calcination temperature and 30%quantity of CuFe2O4 has the highest degradation rate with0.997 min^-1.The results of mechanic mixture of CuFe2O4 and g-C3N4 and of FTIR characterization indicate that CuFe2O4@g-C3N4 exhibited synergistic effect,which greatly increased the degradation efficiency of DCF.（2）MoS2 was synthesized by hydrothermal method.Co（Ⅱ）-MoS2,Cu（Ⅱ）-MoS2,Fe（Ⅱ）-MoS2 and Fe（Ⅲ）-MoS2 were papered by reflux method,and Co（Ⅱ）-MoS2 was applied.The structure and morphology of MoS2 and Co（Ⅱ）-MoS2 were observed on XRD,SEM,HR-TEM,EDS,XPS,Raman,FTIR,TGA.The morphology of them were presented in nano-flower like.Under maintaining the basic structure of MoS2,Co（Ⅱ）-MoS2 was composited with CoS2 and MoS2.Effects of key factors were investigated,and founded that MoS2/PMS and Co（Ⅱ）-MoS2/PMS systems have wide pH applicability.The dosage of the catalyst has a greater impact on the Co（Ⅱ）-MoS2/PMS system,while the dosage of PMS is more inclined to affect MoS2/PMS system.To verify the PMS activation by MoS2 and Co（Ⅱ）-MoS2,quenching and trapping and electron paramagnetic resonance（EPR）experiments were carried out.Degradation of DCF was achieved via non-radical mechanism of MoS2/PMS system.And PMS can generate SO4^·-,HO·,O2^·-and ¹O2 during the DCF remediation of Co（Ⅱ）-MoS2/PMS system.Completely DCF was removed at Co（Ⅱ）-MoS2 0.06 g/L,PMS 0.5 mM and pH 6.5 within 45min with K_obsbs 0.078 min^-1.（3）The crystal structure and morphology of Co（Ⅱ）-MoS2 after used was maintained,and measured by SEM and HR-TEM.Four cycle experiments showed that Co（Ⅱ）-MoS2 had good stability of catalytic.Based on the results of XPS and EPR,the possible degradation mechanism of Co（Ⅱ）-MoS2/PMS might occur as Mo transfer the corresponding mental ions with a higher valence state.And then mental ions with higher valence states will redox by disulfide bonds.Liquid chromatography-mass spectrometry（LC-MS）was used to analyze the intermediate products of the DCF degradation,and it was found that DCF could finally be decomposed into nitrates and chlorides,thereby achieving a high mineralization efficiency of 73%.Compared with other MoS2-based and cobalt-doped catalysts used in PMS systems,Co（Ⅱ）-MoS2 has advantages in Mo leaching,catalytic activity and stability,and has certain application prospects.