| In recent years,with the rapid development of global economy and the continuous improvement of social living standards in China,emerging organic pollutants represented by sulfonamides have been detected many times in water bodies,which will not only affect the water environment ecosystem,but also seriously threaten the health of human and animals.Electro-Fenton is a new Electrochemical Advanced Oxidation Process（EAOP）,which has good degradation ability for various new organic pollutants.In the electro-Fenton process,hydrogen peroxide（H2O2）can be generated in situ on the cathode surface through 2e-oxygen reduction reaction（2e ORR）,which not only helps to produce reactive oxygen species（ROS）,but also avoids the potential risks that may arise from transportation,storage and processing.Researchers are committed to finding a cost-effective electro-Fenton cathode material for the electro Fenton degradation of organic pollutants.Taking the municipal sludge collected from Gaobeidian sewage treatment plant as raw materials,urea,boric acid and ferrous sulfate heptahydrate as nitrogen source,boron source and iron source,nitrogen doped biomass carbon（NSBC）,boron doped biomass carbon（BSBC）and nitrogen boron iron doped biomass carbon（NBFe-SBC）were prepared by hydrothermal and calcination methods,Nickel foam（Ni-F）is also used to prepare electon-Fenton cathode.Sulfamethoxazole（SMX）,sulfamethylpyrimidine（SMR）and sulfachlorpyridazine（SCP）were selected as target pollutants to study the performance of electro-Fenton system with different cathode materials to remove sulfonamides and the optimal reaction conditions.Finally,by detecting the intermediate products in the degradation process of sulfonamides,the possible degradation path was investigated,and the applicability and stability of the prepared electrode in the application process were explored.The main results are as follows:The cathode material（NSBC*@Ni-F）prepared from nitrogen doped sludge based biomass carbon was used for electro Fenton degradation of SMX.When the carbon nitrogen ratio was 1:1 and the load of nsbc was 0.1 g cm-2,the degradation rate reached95.72%and the mineralization rate reached 85.11%within 180 min.At this time,the electro-Fenton reaction is an acid driven reaction.The lower the p H,the better the degradation effect of SMX.The optimal aeration rate and current are 500 ml min-1 and15 m A respectively.The degradation process conforms to the pseudo first-order kinetic model.Boron doped sludge-based biochar cathode material（BSBC#-E）is used for electro-Fenton degradation of SMR.The doping of negative B forms a highly stable B-N bond,reduces the electrode resistance,and makes the functional groups on biochar become the active sites of orr.BSBC#-E has potential application prospects in a wide solution p H range（1-7）.In the degradation experiments of different organic pollutants,BSBC#-E shows superior application and reusability.NBFe-SBC was further prepared by nitrogen boron iron three doped sludge-based biochar.Through the analysis of the degradation performance of SCP under different conditions,the recycling experiment and the morphology characterization of the electrode surface,it is found that the removal rate of SCP increases first and then decreases with the increase of p H.the electrode is still effective for the removal of SCP（64.43-96.85%）in a wide p H range（1-5）.The electrode has strong tolerance and performs well in the recycling process,The ninth time still reached 92.11%.NBFe SBC has excellent performance and simple synthesis process,which makes it a potential alternative cathode material for electro-Fenton remediation of emerging organic pollutants. |
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