Enhanced photocatalytic reduction of trichloroacetic acid using F-TiO2 in the presence of methanol: degradation kinetics and byproducts pathway

Abstract

ABSTRACTTrichloroacetic acid (TCAA) is considered as one of the major of water chlorination by-products. The present work demonstrates decomposition, mineralisation and dechlorination of TCAA by photocatalytic reduction using F doped TiO2. In this regard, the effects of various operational factors including F-TiO2 dose, the initial concentration of TCAA, photo-reaction time and solution pH were examined on the process efficiency. Based on the results, ,,,and, as the common anions in water, had no considerable impact on the TCAA degradation efficiency. Decomposition and mineralisation rate of TCAA by MeOH/UV/F-TiO2process under the optimum conditions (catalyst dosage of 0.34 g L−1, the contact time of 76 min, TCAA content of 1 mg L−1 and pH of 7.9) were found to be 97.1% and 68%, respectively. The decomposition intermediates of TCAAdetected by LC/MS and LC-MS/MStechniques were non-chlorinated compounds, mainly formic and acetic acids. It can be concluded thatMeOH/UV/F-TiO2processcan use as low energy and efficiently treatment method for the degradation of TCAA contaminated water and wastewater.