Enhanced removal of dimethyl phthalate using heterogeneous UVC/VUV-Fenton amendment with Fe3O4@CM-β-CD/rGO catalyst: Efficiency, degradation mechanism and toxicity

• Published in: Chemosphere (Oxford) 2024-03, Vol.352, p.141343-141343, Article 141343
• Main Authors: Dong, Zishui, Li, Sinuo, Rene, Eldon R., Tan, Xuantong, Ma, Weifang
• Format: Article
• Language: English
• Subjects: Dimethyl phthalate; Fe (II)/Fe (III) cycling; Fe3O4@CM-β-CD/rGO; Photocatalysis; UVC/VUV-Fenton
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2024.141343

Dimethyl phthalate (DMP) is widely used as plasticizer, and this kind of plastic industry wastewater is refractory due to the complex chemical structure and endocrine disrupting property. In order to effectively degrade and mineralize DMP contaminated wastewater, a heterogeneous UVC/VUV-Fenton catalyst system was designed with the amendment of targeted design catalyst Fe3O4@CM-β-CD/rGO with core-shell like structure covered with loose convex folded lamellar. The optimum removal and mineralization efficiency of DMP were 98.6 % and 62.8 % in 30 min with 150 mg L−1 Fe3O4@CM-β-CD/rGO and 8 mmol L−1 H2O2. This efficient and fast removal were attributed to a variety of photocatalytic oxidative active species •OH, •O2− and h+ with 59.6%, 29.1% and 9.9% contribution ratio, which mainly took effect on benzene ring open and side-chain fracture by oxidative, hydrolysis and hydrogen substitution determined by the rupture energy requirement from chemical bond in DMP. The target function of CM-β-CD in catalyst controlled the photo-electron generation rate and shorten mass transfer distance by the cladding lamellar, moreover, rGO accelerated the redox between Fe (II) and Fe (III) and electron transfer. The catalytic recovery and removal to DMP kept above 90 % after five recycles. This study provided an excellent performance catalyst and an effective photo-Fenton approach and for the treatment of endocrine disrupting wastewater. [Display omitted] •Nano catalysts Fe3O4 coated by cross-linked lamellar CM-β-CD/rGO was prepared.•Removal efficiency and mineralization of DMP were 98.6% and 62.8% in 30min.•The .•OH, •O2−, and h+ contributed to 59.6%, 29.1% and 9.9% DMP removal.•DMP degnuradation pathways mediated by chemical structure and bond energy.•Catalytic recovery and DMP removal efficiency kept above 90 % after five recycles.