Humic like substances extracted from oil mill wastes in photo-Fenton processes: Characterization, performance and toxicity assesment
Paula García-Negueroles, Sara García-Ballesteros, Lucas Santos‐Juanes, C. Sabater, María Ángeles Castillo, F. López, R. Vicente, Ana M. Amat, Antonio Arques
Abstract
Olive mill waste has been used as sourcing materials for the isolation of humic like substances (OMW-HLS) which have demonstrated its capacity to expand the range of applicability of photo-Fenton process to pH= 5. During the isolation process, membranes of three different pore sizes (300 kDa, 150 kDa and 50 kDa) were employed in order to obtain three batches of OMW-HLS. Four pollutants contained in 2013/39/EC were used as target substances: terbutryn (TBT), diclofenac (DCF), chlorfenvinphos (CVF) and pentachlorophenol (PCP). Results showed that OMW-HLS was able to enhance photo-Fenton at pH = 5, but differences were not significant, either among fractions or with commercial humic substances. Reactions were scaled-up and driven under real sunlight and pollutants removal was faster in the presence of OMW-HLS. Toxicity was monitored according to bioassays based on different organisms or cell lines. Detoxification was observed with and without OMW-HLS, although higher toxicity was detected in the presence of humic acids, most probably due to the surfactant effect, that allows a better contact between pollutant and organism.