Type: Article

Adsorption and photocatalytic degradation of oilfield produced water by visible-light driven superhydrophobic composite of MIL-101(Cr)/Fe3O4-SiO2: Synthesis, characterization and optimization

Journal: Applied Surface Science (01694332)Year: 15 March 2023Volume: 613Issue:

Azmoon P.Farhadian M.^a Pendashteh A.Tangestaninejad S.^a

a :University of Isfahan - IRAN(IR) - Isfahan

DOI:10.1016/j.apsusc.2022.155972Language: English

Abstract

A visible-light driven superhydrophobic composite of MIL-101(Cr)/Fe3O4-SiO2 was synthesized via hydrothermal method. Various physicochemical techniques were employed for the characterization of the nanoparticles such as XRD, FTIR, FESEM, TEM, EDS, BET, UV–Visible DRS, PL, and pHpzc. The adsorption and photocatalytic performance of the synthesized nanoparticles were evaluated by synthetic and real oilfield produced water (OPW) treatment. The optimal loading amount of Fe3O4-SiO2 was determined by analysis tests and investigation of photocatalytic activity. The results showed that the superhydrophobic composite with 35% weight percent of Fe3O4-SiO2 exhibited the maximum removal efficiency. Effect of operational parameters such as pH, reaction time, and initial concentration of pollutants on the removal efficiency were evaluated. The chemical oxygen demand (COD) removal efficiency of synthetic oilfield produced water (SOPW) achieved 95.17% and 96.6% under visible and UV light irradiation by MIL-101(Cr)/Fe3O4-SiO2 (35%), at the optimum conditions of pH 4, photocatalyst dosage 0.5 g/L, COD initial concentration 600 mg/L, and illumination time 150 min. Moreover, the gas chromatography-mass spectroscopy (GC–MS) analysis results showed 97.7% and 99.2% removal efficiency of total petroleum hydrocarbons (TPH) for real and synthetic OPW, respectively. The results of kinetic and isotherm study showed that the kinetic data followed the pseudo-second-order and equilibrium adsorption was described by the Freundlich model. The high specific surface area, narrow bandgap energy as well as the charge carrier separation based on the Z-scheme heterostructure caused the improvement of binary composite photocatalyst features. The results demonstrated that the MIL-101(Cr)/Fe3O4-SiO2 superhydrophobic composite are promising photocatalyst in the degradation of oilfield produced water pollutants. Synergistic effect of adsorption and photocatalytic degradation of OPW help to enhance the removal performance. © 2022 Elsevier B.V.