Photocatalytic degradation of poultry wastewater using activated carbon-supported titanium dioxide

Photocatalytic degradation of real-time poultry wastewater was investigated in a lab-scale batch reactor equipped with low-pressure submergible UV lamp(s). The experiments were conducted using slurry TiO2 (Slurry-TiO2) and activated carbon (AC)- supported TiO2 (granular and powdered), i.e. GAC-TiO2 and PAC-TiO2. The TiO2 coatings on the GAC and PAC surfaces were confirmed by using scanning electron microscopy coupled with energy dispersive spectroscopy.Among the systems investigated, GAC-TiO2 and PAC-TiO2 photocatalytic systems produced 100% total solids, total volatile solids and biochemical oxygen demand (BOD) removals under 14 W and 56 W UV irradiation within 180 min of reaction. In contrast, complete destruction of organics was not achieved in the photolytic experiments conducted with 56 W UV irradiation even after 240 min of reaction. The first-order reaction kinetics was adopted to estimate and compare the rate of BOD removal in the systems. A maximum BOD removal rate constant of 0.987 min(-1) and a maximum BOD removal rate of 320 mg/L/min were observed in 56 W GAC-TiO2 system. The BOD removal rate observed in 14 W GAC-TiO2 (227 mg/L/min) and PAC-TiO2 (247 mg/L/min) systems were comparable; however, GAC-TiO2 was recovered effectively compared to PAC-TiO2. At the same time, photocatalytically treated poultry wastewater using both GAC-TiO2 and PAC-TiO2 was found to be free from coliforms.