Commercial viability of photoreactors in textile wastewater treatment hindered by Titanium dioxide (TiO2) deactivation
Water treatment industry should focus more on water recycling and reuse due to global water shortages as a result of climate change and the increase in volume of toxic and recalcitrant industrial effluents from textile, pharmaceutical and pesticide industries. Water recycling and reuse, which often require sustainable system and high technology should be cost efficient and environmentally friendly. Advanced Oxidation Process (AOP) is widely employed to remove very resistant pollutants that are difficult or costly to treat, this treatment system will dominate the future of water recycle and reuse. Researches focusing on application of such technology recommended titanium dioxide (TiO2) as the preferred catalyst and have carried out investigations and recommend improvements in areas of mass transfer and photon transfer limitations as related to photoreactor intensification processes. These studies have shown potential in the way the photoreactors are designed. Despite such developments, the technology is yet to replace the existing treatment systems in the industry. Data collected from unpublished survey of over 80 major global water treatment companies in July and August 2014, revealed that only about 43% used some forms of AOP, mostly UV and Ozonation. Only about 4% used photocatalysis at pilot scale. Application of photoreactors will be more challenging in textile wastewater treatment due to the presence of ions Cl NO3 SO42 CO32 and PO43 from dissolved salts, they act as inhibitors and poisons that deactivate Titanium oxide (TiO2) reactor beds. This paper reported the findings and recommended solutions for the deactivation phenomenon.