Eco-friendly synthesis of iron oxide nanoparticles using Mulberry leaves extract for heavy metal removal from water

Various natural and anthropogenic factors, including inadequate water treatment, urbanisation, industrialisation, and the intensification of agricultural output, can result in the presence of heavy metals in water, the atmosphere, and sediments. Heavy metal pollution poses a severe threat to aquatic ecosystems and human health due to its persistence, bioaccumulation, and toxicity. Zinc ions (Zn2+), though essential in trace amounts, becomes hazardous at elevated concentrations. This study reports the green synthesis of magnetite iron oxide nanoparticles (Fe₃O₄-NPs) using mulberry leaf (Morus alba) extract as a natural reducing and stabilizing agent. The nanoparticles were tested for Zn2+ removal efficiency under varying conditions of initial concentration (0.5–3.0 mg/L), pH (4–9), contact time (15–90 min), and adsorbent dosage (0.4–1.4 g). Optimal conditions were observed at 1.0 mg/L Zn2+, pH 9, 75 minutes contact time, and 1.0 g adsorbent dosage, achieving a removal efficiency of 98%. Adsorption data fitted well to the Langmuir isotherm (R² = 0.86), indicating monolayer adsorption on a homogeneous surface, while kinetics followed the pseudo-second-order model (R² = 0.95), suggesting chemisorption. These findings highlight the potential of mulberry leaf-derived Fe₃O₄-NPs as an eco-friendly, cost-effective adsorbent for heavy metal remediation, supporting sustainable water treatment strategies.