Preparation Of Waste Mask Carbonaceous Material And Its Oxidation Characteristics Of Activated Persulfate

Advanced persulfate oxidation technology（SR-AOPs）has the advantages of strong oxidation,long half-life and wide p H range,and has significant advantages in the removal of refractory organic pollutants.Carbonaceous materials are widely used in SR-AOPs due to their high specific surface area,rich pore structure and functional groups,controllable regulation and low cost.In order to solve the problems of slow reaction rate and low persulfate utilization rate of a single carbonaceous material,this study used Cu-DMBC（Cu-Disposable mask-based carbon）as the catalyst,and a typical endocrine disruptor Bisphenol A（BPA）was used as a model pollutant to carry out a systematic research from aspects of catalyst preparation and characterization,pollutant degradation and mechanism of action.The main results of the paper are as follows:（1）Using waste masks as raw materials,Cu-DMBC,a carbonaceous catalyst with large specific surface area and efficient activation of persulfate was prepared by impregnation combined with high-temperature roasting.Compared with the modified Cu-DMBC to DMBC,the copper in the catalyst are coated in DMBC,and the surface presents a layered structure with multiple folds,which is loose and porous,which improves the graphitization degree and defect structure of the carbonaceous catalyst,thereby enhancing the catalytic performance of the material.BET test showed that the copper-doped catalyst had a well-developed pore structure and specific surface area,and the pore size,specific surface area and pore volume of the catalyst were 2.37,4.95 and 4.91 times that before modification.On this basis,combined with a variety of characterization methods,the intrinsic properties of Cu-DMBC catalysts and their structure-activity relationship with catalytic activity were expounded.（2）The typical endocrine disruptor BPA was used as the research object to investigate the activation characteristics of Cu-DMBC persulfate.The effects of catalyst dosage,persulfate（PMS）dosage,pollutant concentration,initial p H,inorganic ions and natural organic matter on Cu-DMBC/PMS were analyzed by single-factor experiments,and the removal rate of BPA increased to 97.21%,TOC removal rate increased to 64.78%,and the utilization rate of persulfate could reach 51.02%.The pseudo-primary degradation reaction rate constant(0.1136 min^-1)was 5.0 times that of the modified precatalyst(0.0227 min^-1).The water quality experiments showed that Cl^-and CO₃^2-can promote the reaction process,while HCO₃^-,SO₄^2-,H₂PO₄^-and natural organic matter（humic acid HA）had little influence,and the process showed strong anti-interference performance.（3）The mechanism and path of BPA degradation were analyzed from the aspects of active species composition,catalytic active site and reaction product identification of Cu-DMBC/PMS process.The results show that the incorporation of copper can enhance the electron transfer rate during PMS activation,PMS seizes unstable unpaired electrons in Cu-DMBC catalyst to form a metastable copper complex intermediate[≡Cu（II）-（O）OSO₃]^I,copper complex intermediate has a high oxidation potential,can capture the electrons of PMS in solution to fill the vacancy,so that PMS is oxidized and activated to produce ¹O₂,which provides a non-radical oxidation pathway for the removal of BPA.On the other hand,DMBC can activate PMS to obtain SO₄^·-,·OH,etc.by surface oxygen-containing functional groups and delocalizedπelectrons,providing free radical oxidative degradation pathways.Chemical quenching experiments combined with EPR analysis showed that the main active component of the process was ¹O₂,and the cause could be attributed to the formation of precursor·O₂^-in the Cu（II）/Cu（I）cycle.C=O（carbonyl）activation and self-oxidation of PMS and activation of PMS by Cu-O bonds.Under the joint action of free radicals and non-radical pathways,pollutants form ring-opening products and small molecule acids,and finally are gradually mineralized into non-toxic and harmless CO₂ and H₂O,realizing efficient degradation of pollutants.