Abstract:Silver (I) was removed from aqueous environment by aloe vera shell ash supported Ni_0.5Zn_0.5Fe₂O₄ magnetic nanoparticles. The adsorbent was characterized by several methods including X-ray diffraction (XRD), scanning electron microscopy (SEM), BET isotherm, vibrating sample magnetometer (VSM) and Fourier transform infrared spectroscopy (FT-IR). To determine the absorption of silver (I) by this adsorbent, different pH values (2-7), adsorbent dose (0.01-0.5 g), concentrations of Ag⁺ (50, 100, 200, 300, 500, 700 and 1000 mg/L) and exposure time (5-100 min) were experimented. The highest removal efficiency of Ag⁺ was achieved under optimum condition (30 min and pH=5). The optimum adsorbent dose was 0.20 g (in 50 mL of 100 mg/L Ag⁺ solution), which achieved a removal efficiency of 98.3%. The maximum monolayer adsorption capacity based on the Langmuir isotherm is 243.90 mg/g. Characterization results revealed that specific surface area and porous volume were 814.23 m²/g and 0.726 cm³/g, respectively. The experimental data were fitted well with the Langmuir and Freundlich isotherm models. Synthesized adsorbent has desired surface area and adsorptive capacity for silver (I) adsorption in aquatic environment.

Key words: adsorption; Ag⁺ ions; Ni_0.5Zn_0.5Fe₂O₄; aloe vera