Green-Synthesized TiO₂ Nanoparticles for the Removal of Heavy Metals from Industrial Wastewater: Adsorption, Reduction, and Chelation Mechanisms
Abstract
Heavy metal contamination from industrial wastewater represents a severe environmental threat due to its toxicity, persistence, and non-biodegradable nature. Nanotechnology-based remediation using metal oxide nanoparticles offers high efficiency, rapid action, and cost-effectiveness. This study focuses on the green synthesis of titanium dioxide (TiO₂) nanoparticles using plant extracts and evaluates their ability to remove common heavy metals—Cr⁶⁺, Pb²⁺, Cd²⁺, and Ni²⁺—from industrial wastewater samples. The use of plant phytochemicals serves as a natural reducing, capping, and stabilizing agent, making the process eco-friendly. Synthesized TiO₂ nanoparticles were characterized using UV–Vis, FTIR, XRD, SEM, TEM, and BET analyses. Results showed crystalline anatase-phase TiO₂ with particle sizes between 18–40 nm. Batch experiments revealed high removal efficiencies: 82.4% for Cr⁶⁺, 78.5% for Pb²⁺, 74.1% for Cd²⁺, and 71.3% for Ni²⁺. Mechanistic evaluation indicated that Cr⁶⁺ removal occurred predominantly through reduction (Cr⁶⁺ → Cr³⁺), while Pb²⁺, Cd²⁺, and Ni²⁺ removal was driven by adsorption and chelation to surface hydroxyl groups. The study concludes that green-synthesized TiO₂ nanoparticles are a sustainable, efficient, and low-cost material for industrial wastewater treatment.
How to Cite
Madhu Bala, "Green-Synthesized TiO₂ Nanoparticles for the Removal of Heavy Metals from Industrial Wastewater: Adsorption, Reduction, and Chelation Mechanisms", Vol. 3, Issue 2, 09-05-2025, pp. 70-80.
