A new eco-friendly mesoporous magnetic nanocomposite (MMNCs) known as " methyl alginate@SBA-15/IONP " has been created as a nano-adsorbent system for purifying water contaminants. The production process consisted of multiple stages, commencing with the synthesis of Santa Barbara Amorphous-15 (SBA-15) utilizing the hydrothermal approach. Subsequently, Iron oxide nanoparticle (IONP) was prepared onto SBA-15 through an in-situ co-deposition method. Experimental studies were carried out on various factors affecting the adsorption process of Lead (II) ion (Pb2+), Methylene Blue (MB), and Chlorpyrifos (CPS). Furthermore, Langmuir and Freundlich isotherm models, two kinetic models (pseudo-first-order (PFO) and pseudo-second-order (PSO)), and thermodynamic investigations were conducted for the methyl alginate@SBA-15/IONP MMNCs system. Freundlich isotherm model with PSO kinetics describes the adsorption behavior and thermodynamic parameters show the spontaneous and endothermic nature of adsorption of Pb2+, MB, and CPS in methyl alginate @ SBA-15/IONP MMNCs.