Construction and regulation of high active sites in montmorillonite composite catalyst for the removal of ofloxacin via persulfate activation
Fu-zhi Huang,
Ya-qi Wang,
Wan-yin Gao,
Xiao-qiang Cao,
Yang Zhang,
Ya-nan Shang,
Yi-zhen Zhang,
Yu-jiao Kan
Affiliations
Fu-zhi Huang
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
Ya-qi Wang
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
Wan-yin Gao
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
Xiao-qiang Cao
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China; Institute of Yellow River Delta Earth Surface Processes and Ecological Integrity, Shandong University of Science and Technology, Qingdao, 266590, China; Corresponding author. College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
Yang Zhang
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China; Institute of Yellow River Delta Earth Surface Processes and Ecological Integrity, Shandong University of Science and Technology, Qingdao, 266590, China
Ya-nan Shang
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China; Institute of Yellow River Delta Earth Surface Processes and Ecological Integrity, Shandong University of Science and Technology, Qingdao, 266590, China; Corresponding author. College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
Yi-zhen Zhang
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China; Institute of Yellow River Delta Earth Surface Processes and Ecological Integrity, Shandong University of Science and Technology, Qingdao, 266590, China
Yu-jiao Kan
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, 266590, China; Institute of Yellow River Delta Earth Surface Processes and Ecological Integrity, Shandong University of Science and Technology, Qingdao, 266590, China
In this study, ionic liquids (ILs) were used as organic modifiers by introducing montmorillonite nanolayers containing potential C and N active sites between the montmorillonite nanolayers. Organically modified montmorillonite (ILs-Mt-p) was further prepared by high-temperature pyrolysis under N2 and used for the removal of ofloxacin (OFL) by activated peroxymonosulfate (PMS). Combined with XPS and other characterization analyses, it was found that the catalyst materials prepared from different organic modifiers had similar surface functional groups and graphitized structures, but contained differences in the types and numbers of C and N active sites. The catalyst (3CPC-Mt-p) obtained after pyrolysis of montmorillonite modified with cetylpyridinium chloride (CPC) had optimal catalytic performance, in which graphitic C, graphitic N, and carbonyl group (CO) could synergistically promote the activation of PMS by electron transfer, and 77.3 % of OFL could be removed within 60 min. The effects of OFL concentration, initial pH, and anions on the effects of OFL removal by the 3CPC-Mt-p/PMS system were further investigated. Satisfactory degradation results were obtained over a wide pH range. Cl− promoted the system to degrade OFL, while the presence of SO42−, H2PO4− and HA showed some inhibition, but overall the 3CPC-Mt-p catalysts had a strong anti-interference ability, showing good application prospects. The quenching experiments and EPR tests showed that O2−- and 1O2 in the 3CPC-Mt-p/PMS system were the main reactive oxygen species for the degradation of OFL, and •OH was also involved in the reaction. This study provides ideas for the construction and modulation of active sites in mineral materials such as montmorillonite and broadens the application of montmorillonite composite catalysts in advanced oxidation processes for the treatment of antibiotic wastewater.
