Author/Authors :
kamani، Hossein نويسنده Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran , , Nasseri، Simin نويسنده 1Department of Environmental Health Engineering, School of Public Health and Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran , , Khoobi، Mehdi نويسنده Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran 14176, Iran , , Nabizadeh Nodehi، Ramin نويسنده 3Department of Environmental Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran , , Mahvi، Amir Hossein نويسنده Department of Environmental Health Engineering, School of Health; National Institute of Health Research; Center for Solid Waste Research, Institute fo ,
Abstract :
Background: Un-doped and N-doped TiO2 nano-particles with different nitrogen contents were successfully synthesized by a simple sol–gel method, and were characterized by X-ray diffraction, field emission scanning electron microscopy, Energy dispersive X-ray analysis and UV–visible diffuse reflectance spectra techniques. Then enhancement of sonocatalytic degradation of humic acid by un-doped and N-doped TiO2 nano-particles in aqueous environment was investigated. The effects of various parameters such as initial concentration of humic acid, N-doping, and the degradation kinetics were investigated. Results: The results of characterization techniques affirmed that the synthesis of un-doped and N-doped TiO2 nano-particles was successful. Degradation of humic acid by using different nano-particles obeyed the first-order kinetic. Among various nano-particles, N-doped TiO2 with molar doping ratio of 6 % and band gap of 2.92 eV, exhibited the highest sonocatalytic degradation with an apparent-first-order rate constant of 1.56×10-2 min?1. Conclusions: The high degradation rate was associated with the lower band gap energy and well-formed anatase phase. The addition of nano-catalysts could enhance the degradation efficiency of humic acid as well as N-doped TiO2 with a molar ratio of 6 %N/Ti was found the best nano-catalyst among the investigated catalysts. The sonocatalytic degradation with nitrogen doped semiconductors could be a suitable oxidation process for removal of refractory pollutants such as humic acid from aqueous solution.
