Design and Evaluation of Photocatalytic Reactor Utilizing TiO2/Activated Carbon Catalyst Coated on Mesh for Wastewater Treatment

TiO2/activated carbon (TiO2/AC) was coated on mesh using the dip-coating method employing polyvinyl pyrrolidone (PVP) as a copolymer via a simple mixing method. The obtained catalyst was used to treat real wastewater from a building discharge with a horizontal photoreactor with a continuous flow system. The synthesis of 20%wt TiO2/AC-coated mesh was performed with a fixed TiO2:AC ratio of 1:0.05 wt/wt, as confirmed by employing various characterization techniques, which resulted in a composite TiO2/AC characterized by XRD, FE-SEM, and EDS, confirming the uniform distribution of TiO2/AC nanoparticles coated on mesh substrates. The influence of vital parameters on the best conditions of the photoreactor design, including flow rate (8.0 L/min), light intensity position (5.0 cm), and the number of mesh layers (20 mesh layers), was systematically examined during photocatalytic oxidation. The treatment efficiency of domestic building wastewater was evaluated using a TiO2/AC coated on mesh under visible light irradiation for 120 min. The recirculating batch photoreactor was operated at a continuous flow rate of 8.0 L/min, corresponding to a total treated wastewater volume of 960 L. In real wastewater treatment, the optimized TiO2/AC-coated mesh exhibited the highest activity, achieving approximately 68% BOD removal and 65% COD removal. This study indicates that TiO2/AC-coated mesh can be a good candidate for building wastewater treatment systems using photocatalytic activity under visible light irradiation. However, the TiO2/AC coating exhibited limited reusability, with BOD degradation decreasing to 53% after three cycles. Future work must develop a more stable binder to improve its durability and reusability.