Cadmium removability from aqueous solutions using TiO2 nano photocatalytic compound and rice husk silica

Abstract

Introduction: Pollution from cadmium is enters the environment through different industrial wastewater. The main goal of this study was to investigate the removal efficiency of cadmium by compound of titanium dioxide and rice husk silica from aqueous solutions. Materials and Methods: The removal of Cadmium experiments in this experimental study carried out in batch reactors. Rice silica was prepared in a furnace heated to 800 °C for 4 hours after acid leaching. Deposited silica with TiO2 was prepared in a furnace heated 450 °C for 1 h, after the deposition by Deep Coating method. Scanning Electron Microscope (SEM) was applied the absorbent silica and deposited silica to compare of surface morphology before and after stabilizing the TiO2. The effects of initial concentrations of cadmium, dosage of adsorbent and retention time on the removal of cadmium were studie. Results: Based on the results of SEM the morphology of rice husk silica has been not changed after stabilization of Tio2. The results showed that removal efficiency decreased with increasing the concentration of cadmium and increased with increasing contact time and the dosage of deposition adsorbent. The maximum removal efficiency was obtained up to 89.65% at initial concentration of 1 mg/l of cadmium, 1.5 g/l dosage of deposited adsorbent and retention time of 60 min Conclusion: The results of this study showed that nanophotocatalytic titanium dioxide and rice husk silica could be considered as an effective compound for the removal of cadmium from aqueous solutions