Bisphenol A Mineralization by Integrated Ultrasound-UV-Iron (II) Treatment

Abstract

Bisphenol A (BPA), an organic compound largely used in the plastic industry as a monomer for production of epoxy resins and polycarbonate, is an emerging contaminant that is released in the environmentfrom bottles and packaging. BPA degradation (118 micromol L(-1)) under sonochemical conditions was investigated in this study, using a 300 kHz frequency, with a 80 W electrical power. Under these conditions, BPA was eliminated by the ultrasound process (-90 min). However, even after long ultrasound irradiation periods (10 h), more than 50% of chemical oxygen demand (COD) and 80% of total organic carbon (TOC) remained in the solution, indicating that most BPA intermediates are recalcitrant toward ultrasonic action. Accumulation of hydrogen peroxide from *OH and *OOH radical recombination was also observed. To increase the efficiency of BPA treatment, experiments combined ultrasound with Fe2+ (100 micromol L(-1)) and/or UV radiation (254 nm): Ultrasound/UV; Ultrasound/Fe2+; Ultrasound/UV/ Fe2+. Both UV and Fe2+ induced hydrogen peroxide dissociation, leading to additional *OH radicals and complete COD and TOC removal. Thus difficulties in obtaining mineralization of micropollutants like BPA through ultrasonic action alone, can be overcome by the Ultrasound/UV/ Fe2+ combination. Moreover, this technique was found to be the most cost-effective one. So, the integrated ultrasound-UV-iron(ll) process was shown to be of interest for the treatment of wastewaters contaminated with BPA.

Mineralization of an azo dye Acid Red 14 by photoelectro-Fenton process using an activated carbon fiber cathode

“…At 254 nm, H 2 O 2 absorbs radiation with a molar absorption coefficient of 18.6 L M À1 s À1 , it decomposes with a quantum yield of 0.98, generating OH radical (Eq. (9)) [35]. At the same time, the total mineralization achieved in PEF process could be ascribed to not only hydroxyl radicals from H 2 O 2 photolysis but also to the two processes: the fast photodecomposition of Fe 3+ -oxalatto complexes by UV light and the additional photo-reduction of Fe(OH) 2+ species according to the reaction (6), which could supply additional Fe 2+ and hydroxyl radicals for the mineralization of AR14.…”

Bisphenol A reactions with hydroxyl radicals: diverse pathways determined between deionized water and tertiary treated wastewater solutions

“…Investigations into the removal of bisphenol A from aqueous environments have studied the use of carbon adsorption [11], electrochemical treatments [12], oxidative coupling mediated by horseradish peroxidase [13], as well as photocatalytic oxidation [14][15][16], sonochemical oxidation [17], ozone oxidation [18], and enzymatic oxidation [19]. While each process offers some degree of effectiveness in the breakdown or removal of BPA in aqueous solutions, advanced oxidation processes (AOPs) such as radiolysis, photocatalysis, sonolysis, and UV-peroxide are often considered the best choice for the removal of recalcitrant compounds.…”

Study of Electrochemical Degradation of Bromophenol Blue at Boron-doped Diamond Electrode by Using Factorial Design Analysis

“…AOPs generate hydroxyl radical, the second strongest oxidants known after fluorine. It is able to react with organics giving dehydrogenated or hydroxylated derivatives, up to complete mineralization of organics (Vlyssides et al 2000, Torres et al 2007). One preferred AOP applied in organics degradation is electrochemical treatment, especially the anodic oxidation.…”