Enhanced removal of Ce(iii) and Sr(ii) ions from aqueous solution using ultrasonication-assisted sawdust-TiO2 sorbent

Abstract

The ultrasonication-supported sorption process is regarded as one of the most innovative and promising methods for removing heavy metal ions from contaminated water. This study describes the sorption of Ce(III) and Sr(II) ions from loaded aqueous solutions using ultrasound waves as an aid in the sorption process. These metal ions were sorbed on a sawdust-TiO₂ nanocomposite in the presence and absence of ultrasound. The use of ultrasound with sawdust-TiO₂ nanocomposite to remove the Ce(III) and Sr(II) ions resulted in better sorption for these metal ions than that in the absence of ultrasound. This is due to the synergistic process that occurs when ultrasound waves are combined with the nanocomposite. The main operating parameters are shown, including pH, metal ion concentration, sorbent dose, sonication time, ultrasonic power, temperature, and regeneration process. Kinetic and isotherm models were also investigated, which confirmed that the reaction was compatible with the pseudo-second order and Langmuir isotherm models. Sr(II) and Ce(III) ions exhibited the highest sorption at 45 °C, 0.5 g L⁻¹ sorbent mass, 100 mg L⁻¹ initial concentration for the two metals, pH 5.2 for Sr(II), pH 4 for Ce(III), and 30 min sonication time, which was found to be 92.51 mg g⁻¹ and 73.7 mg g⁻¹, respectively. This study also demonstrated that the sawdust-TiO₂ nanocomposite was more effective at sorbing Sr(II) and Ce(III) ions when compared to other adsorbent materials.