Lead and Cadmium Ions Removal from Wastewater by Advanced Oxidation Process Using TiO2 Nanoparticles

Abstract

A variety of processes can be used in the treatment of industrial wastewaters. Advanced oxidation process (AOP) with TiO₂ nanoparticles (NPs) is one of them. In this study, UV/ TiO₂ / H₂O₂ process had been employed for the removal of lead and cadmium ions. Different operating conditions were used in batch experiments including initial heavy metals concentration ranging between (25, 50, 75 and 100) mg/l, H₂O₂ dosage (400, 600, 700, 900 and 1000) mg/l, TiO₂ (NPs) dosage (0.1, 0.3, 0.5, 0.7 and 0.9) g/l and pH (1, 3, 5, 7, 9, 11 and 13) using  1 Ultra violet (UV) lamp and the detention time was kept constant (210 min). For single and binary systems. The system at optimal conditions and dosage was found at pH= 9, TiO₂NPs = 0.3g/l, H₂O₂=700 mg/l and 25mg/l initial concentration for the ions of lead and cadmium. Results indicated that the optimum efficiencies of lead and cadmium ions removal were 96.69% and 93% for single system and 91.07% and 82.79% for binary system respectively. The pseudo-first order kinetics model fit the experimental data well.