Iranian Journal of Catalysis (IJC) Investigation efficiency of nano photocatalytic compound of TiO2 and rice husk silica in removal of reactive red 198 dye from synthetic aqueous solutions Volume 10 (2020) IJC Issue 1, March 2020 2024 02 03 Investigation efficiency of nano photocatalytic compound of TiO2 and rice husk silica in removal of reactive red 198 dye from synthetic aqueous solutions EN Abdollrahman Mahmoodi Department of Environmental Health Engineering, Semnan University of Medical Sciences, Semnan, Iran. Seyed Mahmood Mehdinia Department of Environmental Health Engineering, Babol University of Medical Sciences, Babol, Iran. Ayat Rahmani Research Center for Health Sciences and Technologies, Semnan University of Medical Sciences, Semnan, Iran. Hamidreza Nassehinia Department of Environmental Health Engineering, Semnan University of Medical Sciences, Semnan, Iran. 0000-0003-4087-1532 Journal Article 2024 02 03 This study was performed with the aim of investigating the efficiency of the Nano photocatalytic of ultraviolet and titanium dioxide compound and rice husk silica adsorbent (UV/TiO2/RHS) in removal reactive red 198 dye from synthetic aqueous solutions. The removal of reactive red 198 dye was done in batch reactors with a volume of 250 ml using RHS deposited by titanium dioxide in the presence of a UV lamp. The effect of pH, immobilization of TiO2 on RHS adsorbent, contact time, nanoparticle mass and initial concentration of dye in removal efficiency were investigated. The results of this research showed that with an increase in pH and alkalinity of the solution, the removal efficiency declined. As the pH changed from 3 to 9, the removal efficiency in UV/TiO2/RHS, RHS adsorbent and UVC radiation declined from 75.25 to 27.87, 8.37 to 3.4, and 16.62 to 3.25%, respectively. The maximum dye removal efficiency obtained by UV/TiO2/RHS was as large as 87.5% under pH=3, contact time of 60 min, nanoparticle mass of 1 g/L, and 25 mg/L concentration of the reactive red 198 dye. Therefore, the rice husk silica as a natural adsorbent in combination with (TiO2/UV) can be used as an effective method for removal reactive red of aqueous solutions on a larger scale by optimizing the parameters affecting the removal efficiency.