Degradation and mineralization of Bisphenol A by the photo fenton process

Abstract

Bisphenol A (BPA; 2,2-bis (4-hydroxyphenyl) propane) is an industrial organic chemical basically used in the plastics industry as a monomer for producing epoxy resins and polycarbonates [1,2]. It is also a well-known endocrine disruptor agent that contaminates surface waters even at low concentration [3]. Unfortunately, BPA cannot be entirely removed from water solutions by conventional treatments. Additionally, in some cases, such treatments can lead to a series of by-products with higher endocrine disrupting effect [4]. Advanced Oxidation Processes (AOPs), among them the Fenton and photo-Fenton processes, are efficient methods for BPA photodegradation [1]. However, they are energy-intensive processes and their cost is ought to be improved by reducing the reaction time as well as the consumption of reagents. In this work, the Fenton and the photo-Fenton degradation of BPA (0,5 L, 30 mg L-1) was addressed. The process efficiency was evaluated under different H2O2 and Fe(II) initial concentrations (2,37-6,41 mM H2O2 and 1,42·10-2-3,92·10-2 mM iron salt), while other variables were fixed (pH=3, 25ºC, UV light source). The treatment performance was assessed for a series of assays from a factorial design and was quantified in terms of the decay rate of total organic carbon (TOC) and the total conversion attained, according to a pseudo first order kinetics [5-6]. The performance of the mineralization may be characterized by determining the two parameters of the model, ¿max (or [TOC]8) and k, which can be obtained by fitting the model to the experimental data under the least squares criterion. The results were plot k in front to identify different clusters and the conditions which produces higher mineralization rates