A water/wastewater treatment apparatus combines photo catalytic oxidation (PCO) with ultraviolet C (UVC) disinfection, resulting in significantly increasing organism kills from up to log 2 to up to log4. In addition, PCO destruction of organic compounds and its super hydrophilicity reduces or eliminates the potential of quartz sleeve fouling. The quartz sleeve of the present invention includes a nano-layer of titanium dioxide (TiO2) on the outer surface thereof. An optimum amount of UVC photons transmits through the quartz sleeve and excites the TiO2 layer, triggering a powerful PCO process that kills organisms on contact and breaks down volatile organic compounds (VOCs) to carbon dioxide (CO2) and water (H2O). The majority of UVC photons will penetrate the quartz sleeve and TiO2 layer to disperse throughout the water/wastewater flow, killing organisms on contact.
