Oxidative degradation/mineralization of dimethyl phthalate (DMP) from plastic industrial wastewater using ferrate(VI)/TiO2 under ultraviolet irradiation

• Published in: Environmental science and pollution research international Vol. 29; no. 10; pp. 15159 - 15171
• Main Authors: Wang, Ping, Ding, Yi, Zhu, Liting, Zhang, Yunhao, Zhou, Sijie, Xie, Linbei, Li, Ao
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2022; Springer Nature B.V
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Benzene; Bioluminescence; Degradation; Earth and Environmental Science; Ecotoxicology; Electron microscopes; Electron transfer; Environment; Environmental Chemistry; Environmental Health; Environmental science; Gas chromatography; Hydroxyl radicals; Independent variables; Industrial wastes; Industrial wastewater; Industrial water; Intermediates; Iron; Irradiation; Mass spectrometry; Mass spectroscopy; Mineralization; Oxidants; Oxidation; Oxidizing agents; Photocatalysis; Photochemicals; Photodegradation; Photooxidation; Phthalates; Polynomials; Research Article; Response surface methodology; Scanning electron microscopy; Synergistic effect; Titanium dioxide; Ultraviolet radiation; Waste Water Technology; Wastewater treatment; Water Management; Water Pollution Control; Water treatment; X-ray diffraction; Ferrate(VI)/TiO; Dimethyl phthalate (DMP); UV; Response surface methodology (RSM); Industrial water treatment; Photocatalytic oxidation
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-021-16636-x

A novel ferrate(VI)/titanium dioxide/ultraviolet [Fe(VI)/TiO 2 /UV] system was successfully established for the photocatalytic oxidation of dimethyl phthalate (DMP). This system demonstrated a higher removal efficiency of DMP (95.2%) than the conventional TiO 2 /UV and Fe(VI) alone systems (51.8% and 23.5%, respectively) and produced obvious synergistic effects. Response surface methodology (RSM), based on a three level, three independent variables design, was conducted through Design Expert 8.0.6 program, and a second-order polynomial model ( R 2 = 0.998) was developed to quantitatively describe the photocatalysis of TiO 2 combined with Fe(VI) oxidation under ultraviolet irradiation. The fresh TiO 2 and photochemical reacted Fe(VI)/TiO 2 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and element dispersive spectrum (EDS), which indicated that Fe(VI) was imprinted into the TiO 2 , and the surface adsorbed Fe-O-(organic) materials inhibited DMP degradation. This photocatalytic oxidant showed high activity and stability after nine cycles without loss of its effectiveness (counting from the second cycle). The intermediates/products of DMP were analyzed by gas chromatography-mass spectrometry. The proposed pathway for DMP degradation involved one electron transfer of hydroxyl radical and breaking of the ester bond and benzene ring. The mineralization efficiencies of DMP in actual industrial wastewater and simulated water were 87.1% and 95.2%, respectively, suggesting practical field applications. A ecotoxicity test (17.3% inhibition on bioluminescence) in treating actual industrial wastewater containing DMP implied that the proposed Fe(VI)/TiO 2 /UV had a potential for industrial water treatment.