PULSE LASER ABLATED TITANIA-HAEMATITE NANOCOMPOSITES FOR THE REMOVAL OF LEAD AND ARSENIC FROM WASTEWATER

Abstract

Water contamination by toxic heavy metals, particularly lead (Pb²⁺) and arsenic (As³⁺), poses a severe environmental and public health risks due to their persistence, bioaccumulation, and high level of toxicity. Conventional wastewater treatment methods, such as chemical precipitation and membrane filtration often suffer from high costs, energy demands, and secondary pollution. Therefore, there is a critical need for efficient, cost-effective, and sustainable materials for heavy metal removal. Nanocomposites, particularly those based on titania (TiO₂) and haematite (α-Fe₂O₃) offer promising adsorption and photocatalytic properties. The primary objective of this study is to synthesize titania (TiO₂)- haematite (α-Fe₂O₃) nanocomposites via pulsed laser ablation in liquid (PLAL) and evaluate their efficiency in removing Pb²⁺ and As³⁺ from wastewater. The nanocomposites were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FTIR) spectroscopy and UV-Vis spectroscopy to determine their structural, morphological, and optical properties. The adsorption efficiency of Pb²⁺ and As³⁺ was evaluated under varying parameters such as laser fluence, solvent pH, contact time, and initial metal concentration. The results indicated that the TiO2-(α-Fe2O₃) nanocomposites exhibited high adsorption capacity due to their large surface area, synergistic photocatalytic effects, and strong metal affinity. The observation of improved heavy metals removal efficiency of the proposed nanocomposites was ascribed to the synergy between TiO2 nanoparticles and α-Fe2O3 nanoparticles, indicating their wastewater treatment potential. The removal efficiency exceeded 90% for both metals under optimized conditions, demonstrating the potential of these nanocomposites as an eco-friendly and effective material for wastewater treatment. These findings affirmed the unique effectiveness of nanocomposites for water treatment implementation. This research contributes to sustainable water treatment technologies by introducing an environmentally friendly solution for heavy metal removal.