Weathered sand of basalt as a potential nickel adsorbent

Abstract

The natural mineral, weathered sand of basalt (WSB), was utilized to investigate whether nickel can be removed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were performed to characterize WSB. The effects of various conditions, i.e., contact time, pH, WSB dosage, particle size of WSB, and temperature were analyzed. The experimental data were analyzed by two widely used equations, i.e., Langmuir and Freundlich isotherms. The results obtained revealed that the WSB adsorption process was more consistent with the Langmuir model than the Freundlich equation. The kinetics data fitted well into the pseudo-second-order model. The findings of the present study indicate that WSB could be used for removing nickel from aqueous solution. Moreover, its concentration can be reduced from 1.0 mg/L to ND (not detected, below the device limit <0.01 µg/L) under the optimal condition. Therefore, WSB is considered to be usable as one of the adsorbents for nickel removal in water. In addition, since heavy metals are often present in low concentrations in water, it is considered that WSB can be applied as one of the effective alternatives for removing low-concentration nickel.