Dual-phyto mediated synthesis of magnesium zinc ferrite nanoparticles using Parthenium hysterophorus and Nerium oleander: a novel strategy for eco-friendly wastewater detoxification

Water contamination due to municipal, agricultural, and industrial discharge is a constant environmental issue, and dye-contaminated effluents from the textile industry are a particularly recalcitrant and toxic contaminant. This investigation reports the green synthesis of Mg/Zn ferrites using extracts of Parthenium hysterophorus (P-H) and Nerium oleander (N-O) as reducing and stabilizing agents, and thus produces P-H/MgZnFe₂O₄ and N-O/MgZnFe₂O₄ nanostructures. A batch adsorption experiment has been planned to determine the effect of pH, dosage of adsorbent, contact time, temperature, and initial concentration of dyes on removal efficiency. The adsorption kinetics followed pseudo-second order and intraparticle diffusion models, indicating chemisorption and diffusion-controlled mechanisms; equilibrium data were well described by the Langmuir, Freundlich, Temkin, and Harkins–Jura isotherms, suggesting a multilayer mechanism and heterogeneous adsorption; thermodynamic analysis showed negative values of Gibbs free energy and endothermic behaviour, which confirms the spontaneity and feasibility of the adsorption process. The presence of detergents and surfactants, ubiquitous in textile wastewater, was also found to modulate dye-adsorbent interactions. Mg-doped ZnFe₂O₄ NPs, green-synthesized by P-H and N-O extracts, were tested for wastewater treatment. The synthesized nanocomposites had the highest adsorption capacity of approximately 42 mg g⁻¹ at pH 2 and had a removal efficiency greater than 90% in 80 minutes. P-H/Mg–ZnFe₂O₄ was the best adsorbent studied, demonstrating its ability to be a sustainable wastewater treatment system.