Separation and Purification Technology, Vol.208, 19-26, 2019
Electrochemical treatment of butylated hydroxyanisole: Electrocoagulation versus advanced oxidation
This work compares the removal of butylated hydroxyanisole (BHA), a ubiquitous antioxidant in food and pharmaceuticals, from water either by electrocoagulation (EC) with an Fe/Fe cell or H2O2-based electrochemical advanced oxidation processes like electrochemical oxidation (EO-H2O2), electro-Fenton (EF) and photoelectroFenton (PEF) with an air-diffusion cathode. BHA degradation by EC was very poor, whereas the dissolved organic carbon (DOC) was more effectively abated in urban wastewater. The effect of pH, number of Fe/Fe pairs and current on the EC performance was examined. The additive was also slowly degraded by EO-H2O2 with a RuO2 based or BDD anode in 50mM Na2SO4 solution. In the simulated matrix, BHA decay by EO-H2O2 was substantially enhanced owing to active chlorine generation from anodic oxidation of Cl-, whereas the center dot OH-mediated oxidation at the BDD surface accounted for DOC decay. In EF and PEF, the center dot OH produced in the bulk upgraded the mineralization, primordially using BDD. In raw urban wastewater at natural pH 7.9, the time course of BHA and DOC contents was affected by NOM oxidation, being accelerated in the order: EO-H2O2 < EF < PEF. The quickest decontamination of urban wastewater occurred in PEF at pH 3.0, because of the higher amounts of center dot OH in the bulk along with WA photolysis.
Keywords:Butylated hydroxyanisole;Electrochemical advanced oxidation processes;Electrocoagulation;Industrial additives;Urban wastewater