Synthesis of N-doped TiO2 nanoparticle and its application for disinfection of a treatment plant effluent from hospital wastewater
Hossein Kamani, Seyed Davoud Ashrafi, Éder C. Lima, Ayat Hossein Panahi, Mahdieh Garkani Nezhad, Hossein Abdipour
Abstract
ABSTRACT Disinfection is one of the most important stages of water and wastewater treatment. Today, the use of photocatalytic processes by sunlight as a sustainable way of water disinfection has been noted. The purpose of this study was to remove coliform and fecal coliform from the effluent of a hospital sewage treatment plant using the solar/N-doped titanium dioxide (TiO 2 ) process. In order to conduct the experiments, the raw samples (effluent of secondary sedimentation) were taken from the Ali Ibn Abi Talib hospital wastewater treatment plant in Zahedan City, Iran. N-doped TiO 2 nanoparticles and the samples were poured into the reactor and then exposed to direct sunlight in summer. The results indicated that the photocatalytic process efficiency was enhanced by increasing reaction time and nanoparticles dosage. Furthermore, it was found that N-doped TiO 2 nanoparticles and sunlight had a synergistic effect on the deactivation of coliform and fecal coliform. The number of coliforms and fecal coliforms bacteria cells decreased from 5 × 10 5 to 7 × 10 3 MPN/100 mL and 4 × 10 3 to 2 × 10 2 MPN/100 mL in the solar/N-doped TiO 2 process after 150 min, respectively. It has been generally concluded that the solar/N-doped TiO 2 process can effectively deactivate a wide range of real effluent microorganisms on a laboratory scale.