Valorisation of a by-product from the TiO2 pigment industry for its application in advanced oxidation processes

Abstract

The aim of this study was to find a recycling use for waste material (WTiO) that results from the extraction process of TiO from ilmenite in the pigment industry. In view of its high TiO content, the photocatalytic activity of this material was tested in the degradation of humic and fulvic acid substances (HFAs) and showed low levels of photoactivity, as was the case for the commercial photocatalyst Aeroxide TiO P25 (P25). However, due to its high Fe content, an important application was observed for WTiO as an HFA coagulant and catalyst in Fenton and photo-Fenton processes. A two-stage process of coagulation and photo-Fenton treatment was subsequently designed and conducted at laboratory and small pilot scale. High percentages (above 95%) were obtained in total organic carbon (TOC) removal.