The development of environmentally friendly magnetic nanoadsorbents has attracted considerable attention due to their potential applications in various felds, including environmental remediation. In this study, a novel magnetic nanoadsorbent was synthesized using spirulina algae powder and eco-friendly chitosan to remove mercury ions from aqueous solutions. The synthesized magnetic nanoadsorbent was characterized using various techniques including X-ray difraction, feld emission scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and vibrating sample magnetometry. Response surface methodology was used to evaluate the efectiveness of the magnetic nanoadsorbent in removing mercury ions by investigating several important parameters, including the pH of a solution, contact time, initial concentration and adsorbent dosage. The results showed that the magnetic nanoadsorbent exhibited high adsorption capacities toward mercury ions, with a maximum adsorption capacity of 58.8 mg/g under specifc conditions, including a contact time of 35 min, an initial concentration of 55 mg/L, a pH of 4.25 and an adsorbent dosage of 25 mg/g. In addition, the Freundlich isotherm model efectively fts the experimental data. Overall, the developed magnetic nanoadsorbent composed of spirulina algae powder and chitosan provides an environmentally friendly and efcient solution for the removal of mercury ions from polluted water sources.
