A review on nickel(II) adsorption in single and binary component systems and future path

Abstract

Water polluted with heavy-metal ion has been a major problem in recent years. Among various metal ions, nickel(II) is a priority pollutant commonly found in industrial wastewater. As a highly toxic element at an elevated concentration, Ni(II) can pose a serious threat to our ecological environment as well as human being. Ni(II) adsorption from wastewater is a must for environmental management and sustainability. Remediation of Ni(II) contaminated water is possible through adsorption onto various innovative adsorbents from the aquatic environment. The current review looks at the present status of the research done so far Ni(II) adsorption using various adsorbents from wastewater. Ni(II) adsorption kinetics, edges, isotherm, thermodynamic parameters, and Ni(II) adsorption mechanism have also been talked over. Efforts have also been made to steer out of the advantages and disadvantages of adsorbents and the future research need in Ni(II) adsorption by adsorbents. Agricultural based substrates and nanosized metal oxides have been found a hopeful alternative for Ni(II) adsorption from wastewater. The Ni(II) primarily adsorbed onto a homogeneous substrate forming a monolayer. Ni(II) generally formed outer-sphere complexes at low pH values while it formed inner-sphere complexes at higher pH. More than one species is being sorbed, or more than one type of surface site is involved in Ni(II) adsorption process or both. However, significant research is needed to understand Ni(II)-surface interaction mechanism at the solid-water interface. This review can fill the lacuna of researchers who would like to do more research in this related area in depth.