وصف البحث
Sodium percarbonate (SPC) is extensively utilized in advanced oxidation processes (AOPs) for water treatment owing to its safety, stability, and environmental sustainability. The practical application of SPC-AOPs encounters obstacles concerning water quality criteria, availability of active sites, activation approach, and ecotoxicity. Herein, an innovative activation approach was provided featuring the synthesis of rice shell biochar (RBC) modified with bimetal Co/Fe in an electrochemical advanced oxidation system (EAOPs) for SPC activation and tetracycline (TC) degradation, which improves the Fe+2/Fe+3 and Co+2/Co+3 cycling by redox couples synergistically. The properties of the catalysts were analyzed to elucidate the intrinsic differences in reactive oxygen species (ROS) generation. Hydroxyl radicals and singlet oxygen were the primary reactive oxygen species identified through indirect quenching experiments, as verified by electron paramagnetic resonance analysis.TC removal reached 100 % in RBC: Fe/Co21/ EAOPs/SPC system with kinetic rate (1/m = 1.4943 min−1) and 68.84 % TOC abatement. Density functional theory simulation indicated that the Fe/Co sites in RBC: Fe/Co21 were the predominant active sites for SPC activation, exhibiting more adsorption energy and enhanced oxidative activity towards SPC than RBC sites. After the fifth cycle, the RBC:Fe/Co21/ EAOPs/SPC successfully attained a TC degradation efficiency of 75 % and the leaching concentration of Co (180.7,3.27 μg/L) and Fe (5.9 μg/L). The universality of the degradation system's performance had been tested. The TC breakdown intermediates were determined by mass spectrometry, and their toxicity to microorganisms was assessed by the growth of E. coli. The findings would provide a reference for the SPC-EAOPs activation system for effective removal of refractory antibiotics.
