Removal of Bisphenol A from water using Fe2O3/ZnO photocatalytic process in the presence of visible light

Bisphenol A (BPA) is one of the pollutants of water resources that disrupts the endocrine glands and is resistant to biodegradation. This study aimed to evaluate the performance of photocatalytic process using Fe2O3/ZnO in the presence of visible light for degradation of BPA in contaminated water.

A descriptive-analytical study in batch mode was performed on synthetic contaminated water samples made in the laboratory. In this study Fe2O3/ZnO catalyst was used to decompose BPA in the presence of visible light. Moreover, the effect of some parameters such as solution pH, catalyst dose, BPA concentration, and radical scavengers on removal efficiency was investigated. The catalystchr('39')s decomposition kinetics and surface properties were also determined using XRD, SEM, DRS, EDX, and BET techniques.

BET analysis showed that the Fe2O3/ZnO catalystchr('39')s surface area was 15.86 m2/g, and the band-gap was 2.7 eV. The highest BPA removal efficiency was obtained at neutral pH, which, considering the interpretation of pKa of BPA and pHpzc of catalyst, seems reasonable. Moreover, with increasing the catalyst dose to 0.04 g/L, BPA removal efficiency increased, and this catalyst dose was selected as the optimum dose. The removal efficiency of BPA was decreased with increasing the initial concentration of BPA. The photo-degradation of BPA fits pseudo-first-order degradation kinetics, and by increasing the initial concentration of BPA from 10 to 100 mg/L, the kobs decreased from 0.012 min-1 to 0.0022 min-1. Radical scavenger tests showed that hydroxyl radical (HO●) and generated holes (h+) play the main role in the degradation of BPA.

Considering the high photocatalytic performance of the Fe2O3/ZnO in the presence of visible light, it is recommended for the decomposition of persistant organic compounds in contaminated water.