Effective removal of highly toxic Pb²⁺ and Cd²⁺ ions using reduced graphene oxide, polythiophene, and silica-based nanocomposite

Abstract

The purpose of this study is to develop a highly capable reduced graphene oxide, polythiophene, and silica-based low-cost composite material and investigate its adsorption behavior. The synthesized composite was analyzed using various analytical methods and applied to eliminate highly toxic metallic pollutants from contaminated water. Different adsorption parameters were used to decontaminate the wastewater. The best conditions for removing Pb²⁺ and Cd²⁺ ions were obtained. The adsorption efficiency was determined to be 65.9 (±0.9) % and 61.5 (±1.4) % at contact time of 60 minutes, 75.9 (±0.7) % and 76.1 (±0.8) % at 105 mg of adsorbent, 98.7 (±0.7) % and 93.2 (±0.6) % at pH 6 for Pb²⁺ and Cd²⁺ ions. The adsorbent was re-utilized up to three times with good adsorption effectiveness. A thermodynamic study has indicated the spontaneity of the adsorption process. The pseudo second order rate constant were found to be 19.1 (±1.5) and 16.5 (±1.7) g/mg/min for Pb²⁺ and Cd²⁺ ions, respectively.

Graphical Abstract

Keywords:

• Synthesis
• characterization
• adsorption
• toxic metallic pollutants
• re-utilisation

Acknowledgements

We are very thankful to the Division of Research & Innovation (Uttaranchal University, Dehradun) for encouragement and seed funding for the research work.