Fabrication of a double‐helical photocatalytic module for disinfection and antibiotics degradation

Abstract A double‐helical photocatalytic module was fabricated via an annealing process following an anodic oxidation procedure, and installed into a commercial UV sterilizer to structure continuous‐flow photocatalytic device. Benefiting from the superior mass transfer of double‐helical structure to common flat plate or corrugated plate, as well as the improved adhesion between Ti support and TiO 2 layer, the photocatalytic device displayed potential in practical disinfection and degradation of organics. During photocatalytic disinfection process with 21 mJ/cm 2 of UV dose, the concentration of Escherichia coli decreased from 1.71 × 10 7 CFU/L (typical for municipal wastewater) in influent to 2,720 CFU/L in effluent water, which met the wastewater discharged standard of China. Escherichia coli reactivation ratio for the photocatalytic device was only one‐tenth of that for UV sterilizer. Furthermore, taking phenol, bisphenol A, and four antibiotics as targets, the device was demonstrated to promote the degradation of photodegradable pollutants via photocatalysis. These results highlight a feasibility of photocatalytic technology as a supporting role in practical wastewater treatment. Practitioner points TiO 2 nanotube array was embedded in the surface of double‐helical Ti support to avoid detachment. This double‐helical photocatalytic module was installed into a commercial UV sterilizer to structure a continuous‐flow device. The continuous‐flow device was effective in sterilizing bacteria and decomposing photodegradable organic pollutants in wastewater. Improving the performance of UV technology was proposed as a feasible approach for the practical application of photocatalysis.