Enhanced remediation of simulated wastewaters contaminated with 2-chlorophenol and other aquatic pollutants by TiO2-photoassisted ozonation in a sunlight-driven pilot-plant scale photoreactor

Solar photoassisted remediation of a simulated wastewater contaminated with 2-chlorophenol (2-CP) was carried out by various advanced oxidation processes in a pilot-plant-scale Pyrex glass tubular-type photoreactor using solar cell derived electricity to drive the whole setup. The UV-assisted degradation and mineralization (loss of total organic carbon, TOC) of 2-CP in the co-presence of TiO2 and ozone (UV/TiO2/O3) was enhanced significantly compared with ozonation alone (UV/O3) and conventional TiO2 photocatalysis in oxygenated dispersions (UV/TiO2/O2). The mineralization process was monitored by TOC assays and chloride ion analyzes. The utilization of immobilized TiO2 was also examined with a TiO2-coated glass photoreactor and compared with dispersed TiO2 in aqueous media. In addition, simulated wastewaters contaminated with the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), the endocrine disruptor bisphenol-A (BPA), the anionic surfactants sodium dodecylbenzenesulfonate (DBS) and sodium butylnaphthalenesulfonate (BNS), together with the cationic benzyldodecyldimethyl- ammonium bromide (BDDAB) surfactant were also efficiently remediated under otherwise identical conditions. The TiO2-photoassisted ozonation of organic wastewater contaminants is a promising synergistic methodology to accelerate the remediation of such wastewaters, even when the TiO2 is immobilized which can lead to reduced costs of operation.