Scale-up of photoreactor with TiO2 thin layer for wastewater treatment

Abstract

This study is devoted to the scale-up potential of TiO2/UV photocatalyst for real wastewater treatment including its durability tests. The activity of the prepared TiO2 layers was first tested in a laboratory reactor on key representative pollutants diclofenac, chloramphenicol and triclosan. A special pilot plant reactor of a two-tube system with 21 stainless steel annulets covered by TiO2 thin layers and the inner volume of 3.5 L was constructed. Pilot tests were performed with wastewater from the pharmaceutical industry containing danazol and norethisterone with the concentration varying between 4 and 7 mg L−1 at the flow 18 L h−1 and municipal wastewater at the output sewage plant for 67,000 inhabitants containing bisphenol A, 4-nonyphenol, estron, ethinylestradiol and triclosan in the concentrations of the individual contaminants varying between 50 and 600 ng L−1 at the flow 200 L h−1. After the treatment during the pilot photocatalytic test, the concentration of individual contaminants decreased by 82–100%, while no decrease in the efficiency of the photocatalytic process was recorded during the long-term tests lasting for 3–6 months. HIGHLIGHTS A new type of pilot plant reactor was designed for TiO2/UV photocatalysis scale-up.; Excellent durability of TiO2 layer on annulets was corroborated on a durability tester.; Efficiency of pilot reactor was tested on various drugs and real wastewater successfully.; The lifespan of the photocatalyst was corroborated by a 3-month-long test.;