The Efficiency Of Chalcopyrite-based Catalyst Activated Peroxymsulfaonote In The Treatment Of Typical Pharmaceutical Wastewater

In China,millions of tons of various drugs are produced each year,and a large amount of production wastewater is discharged into natural water bodies without effective treatment,such as Carbamazepine（CBZ）,N-N Dimethylformamide（DMF）,sulfonamides,analgesics,antihistamines,and anti-tuberculosis drugs,etc.Most of these pollutants are difficult to biodegrade and are Persistent Organic Pollutants（POPs）,which cannot be effectively removed by traditional treatment methods.In recent years,the advanced oxidation technology based on peroxymonosulfate（PMS）has gradually become a research hotspot because of its fast reaction rate and strong oxidation capacity.In this study,the chalcopyrite-based catalyst/PMS system was used to treat and analyze the efficacy of typical pharmaceutical pollutants（CBZ and DMF）,and then the chalcopyrite-based catalyst was used for the treatment of actual pharmaceutical wastewater,and the main research contents and conclusions are as follows.（1）The structure of natural chalcopyrite（NCP）was characterized and analyzed,and the mechanism of CBZ degradation by the NCP/PMS system was investigated.The characterization and analysis of NCP using SEM-EDS,BET,VSM and XRF showed that NCP is a mesoporous material rich in Fe-Cu-S and exhibits paramagnetic properties at room temperature.The effects of NCP dosing,PMS dosing,p H,temperature and inorganic anions on the degradation of CBZ by NCP/PMS system were systematically investigated.The results showed that when the initial concentration of CBZ was 5.0 mg/L,the removal rate of CBZ could be as high as82.34%after 30 min of reaction under the conditions of NCP and PMS dosage of 1.0g/L and 0.5 g/L,respectively.The radical quenching test and EPR analysis yielded that the main reactive substances in the NCP/PMS system were sulfate radicals（SO₄^-·）,hydroxyl radicals（·OH）and singlet oxygen（¹O₂）,and the reaction mechanism and degradation pathway of CBZ degradation by NCP/PMS system were studied in detail by XPS and LC-MS.（2）A new catalyst of Co-modified natural chalcopyrite（Co-NCP）was prepared,and the mechanism of degradation of DMF wastewater by Co-NCP/PMS system was analyzed.Natural chalcopyrite has problems such as poor adsorption and low impregnation efficiency,and the Co-NCP catalyst was prepared by calcination-impregnation method,and the modified Co-NCP catalyst possessed a larger specific surface area by BET analysis.The modified Co-NCP catalyst was applied to the degradation test of DMF simulated pharmaceutical wastewater,and the COD removal rate of DMF wastewater with a mass concentration of 120.0 mg/L could reach 91.61%within 40 min at the Co-NCP catalyst dosage of 4.0 g/L and PMS of 4.0 g/L,while the removal rate before modification was only 33.36%.The degradation pathway of DMF was analyzed by LC-MS,which showed that the main degradation products of DMF were methanol,formaldehyde,formic acid and other small molecules.（3）To further investigate the application value of chalcopyrite-based catalysts in DMF-based actual pharmaceutical wastewater,Co-NCP high-efficiency catalyst was used for the deep treatment test of actual pharmaceutical wastewater.The optimum reaction conditions for this reaction system were determined as the dosage of Co-NCP was 10.0 g/L,the dosage of PMS was 6.0 g/L,and the p H was 5.The COD of the treated pharmaceutical wastewater was reduced from 450.0 mg/L to 144.7mg/L under this working condition,and the removal rate could reach 67.84%.This part of the study was only used to verify the practical value of the chalcopyrite-based catalyst,and further studies are pending for subsequent experiments.