文献速递|重庆大学ACB:铁（III）减轻了铁基双金属/PMS 系统氧化有机污染物的 pH 值依赖性

第一作者：Chaowei Yuan

通讯作者：李伟 副教授

通讯单位：重庆大学环境与生态学院

DOI:10.1016/j.apcatb.2024.125002

Fig. 1. (a) Schematic diagram of the MnFe2O4 synthesis. (b) SEM images of MnFe2O4 with (b) 2 μm, (c) 500 nm, and (d) 100 nm scale (Embedded average pore diameter of MnFe2O4. (e) XRD patterns of MnFe2O4. (f) HR-TEM image of MnFe2O4. (g) Energy-dispersive X-ray (EDX) mapping.

Fig. 2. (a) Degradation of phenol in different reaction systems with buffer and (b) the corresponding kinetic curves. (Conditions: 5 mg/L phenol, 0.4 g/L catalyst, 0.5 mM PMS, and pH = 6.2 ± 0.3). (c) The reactive species quenching experiments under pH 3.2 condition. (Conditions: 5 mg/L phenol, 0.4 g/L MnFe2O4, 0.5 mM PMS, [MeOH] = [TBA] = 100 mM, BQ = L-His = 10 mM, PMSO = 0.1 mM and pH = 3.2 ± 0.3). (d) Degradation of phenol in buffer with different pH and (e) the corresponding reaction rate constants. (Conditions: 5 mg/L phenol, 0.4 g/L MnFe2O4, 0.5 mM PMS). (f) The reactive species quenching experiments in buffer under pH 6.2 conditions. (Conditions: 5 mg/L phenol, 0.4 g/L MnFe2O4, 0.5 mM PMS, [MeOH] = [TBA] = 100 mM, BQ = L-His = 10 mM, PMSO = 0.1 mM and pH = 6.2 ± 0.3). (g) Reaction rate constants for the phenol degradation by different monometallic oxide systems in the buffer. (Conditions: 5 mg/L phenol, 0.8 g/L catalyst, 0.5 mM PMS).

Fig. 3. (a) Mn 2p and (b) Fe 2p XPS spectra of MnFe2O4 before and after the catalytic reaction at pH 6.2 conditions. (c) Increased Mn(IV) and Fe(III) content after catalytic reaction at different pH conditions. (d) Phenol degradation in Fe2O3/Mn2O3/PMS system with buffer. (Conditions: 5 mg/L phenol, 0.4 g/L catalyst, 0.5 mM PMS, 1 mM KSCN, and pH = 6.2 ± 0.3). (e) The pH in trends of initial pH 5.2 ultrapure water for adding different Fe/Mn monometallic oxides (1 g/L). (f) COHP analysis for the OH− adsorption on the Fe site and Mn site respectively. (g) Calculated charge density and (h) adsorption energy of OH− on the Fe site and Mn site respectively.

Fig. 4. The adsorption energy of (a) PMS and (b) phenol on MnFe2O4/HO-MnFe2O4, respectively. (c) Zeta potentials of the MnFe2O4 at different pH values. (d) Proposed mechanism for broad pH applicability of MnFe2O4/PMS system. (e) Reaction rate constants for the phenol degradation by different bimetallic oxide systems in the buffer. (Conditions: 5 mg/L phenol, 0.4 g/L catalyst, 0.5 mM PMS).

Fig. 5. (a) The removal of different pollutants in the MnFe2O4/PMS system with buffer. (Conditions: 5 mg/L pollutants, 0.4 g/L MnFe2O4, 0.5 mM PMS, pH = 6.2 ± 0.3). (b) COD removal of actual wastewater in the MnFe2O4//PMS system. (Conditions: 0.4 g/L MnFe2O4, 2 mM PMS, and initial pH = 11.1). (c) The predicted acute and chronic toxicity of phenol and its degradation products. (d,e) Design of an automated reactor with melamine sponges loaded with MnFe2O4 for the degradation of pollutants. (f) RhB samples at different times. (g) Reusability tests of the MnFe2O4/PMS system with buffer. (Conditions: 5 mg/L phenol, 0.4 g/L MnFe2O4, 0.5 mM PMS, pH = 6.2 ± 0.3). (h) RhB concentration in the effluent from a continuous-flow reactor with buffer. (RhB 10 mg/L, 1 mM PMS, pH = 6.2 ± 0.3 and flow rate: 60 mL/min).