Removal of Orange G by nitrogen-doped biochar loaded with CuS activated persulfate
In the present study,a composite material of nitrogen-doped biochar loaded with copper sulfide(CuS@NBC)was synthesized using wheat straw and urea via a pyrolysis-coprecipitation method.The physicochemical properties of CuS@NBC were analyzed via X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),and Brunauer-Emmett-Teller(BET)surface area and porosity analysis.The prepared CuS@NBC was used for activating peroxydisulfate(PDS)to degrade the azo dye Orange G(OG).This study investigated the effect of various parameters,including PDS concentration,CuS@NBC concentration,and initial pH,on OG removal efficacy,as well as the recycling performance of CuS@NBC.The results showed that at an OG concentration of 50mg/L,a CuS@NBC concentration of 0.2g/L,and a PDS concentration of 4mmol/L resulted in the OG removal and mineralization rates of 99.16％and 36.79％,respectively.Effective OG removal was observed within a pH range of 5～9.CuS@NBC maintained an OG removal rate of 75.92％even after five reuse cycles.Electron paramagnetic resonance spectroscopy and free-radical quenching experiments indicated that O2-and 1O2 were the primary active oxygen species in the CuS@NBC/PDS system.X-ray photoelectron spectroscopy(XPS)analysis revealed that Cu+,C=O,-COOH,and graphitic nitrogen on the surface of CuS@NBC were the main active sites for PDS activation.Ion coexistence experiments demonstrated that OG removal was enhanced by Cl-,while NO3-had almost no effect on it and HCO3-and Humic acid(HA)considerably inhibited it.In addition,based on experimental results,a potential activation mechanism for the CuS@NBC/PDS system was proposed.
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维普
