LAUSR

Abstract Wastewater pollution by heavy metals has undesirable effects on human health and the environment. Nickel is one of the most notorious contaminants in effluent streams of industries. Therefore, it is necessary to uptake nickel ions from wastewater to prevent underground water contamination. For doing so, the synthesized γ -alumina nano-adsorbents is used to remove nickel ions from wastewaters. Indeed, the solvothermal method is employed for fabricating this nano-adsorbent with both low and high specific surface area (LSSA and HSSA). The synthesized nanoparticles are characterized using the Emmett and Teller (BET) surface area, X-ray diffraction (XRD), and scanning electron microscope (SEM) techniques. The BET test reveals that the synthesized γ -alumina samples have different surface and pore characteristics. The XRD test confirms that the HSSA alumina has higher purity than the LSSA one. The effect of temperature (25-50 °C), nickel ion initial concentrations (25-500 mg/L), nano-adsorbent dosage (0.6-2 g), pH (4-11), and contact time (15-90 min) on nickel removal has been experimentally studied. The temperature=40 °C, adsorbent dosage=2 g, pH=4, nickel ions initial concentration=25 mg/L, and contact time=60 min is the optimum condition for nickel uptake. In this optimum condition, 99.6% and 96.9 of nickel were removed by the HSSA and LSSA nano-adsorbents, respectively.