Zerovalent nickel nanoparticles performance towards Cr(VI) adsorption in polluted water

Heavy metals are one of the most common types of pollutants in ground water due to their wide sources, non-degradability and high toxicity. Many traditional wastewater treatments were not capable of removing enough such contaminants in order to meet quality standards. Nanosized zerovalent transition metals have emerged as a great candidate for ground water remediation, due to their simplicity and low fabrication cost, furthermore they can comply with simple chemical synthesis. Here, we present the synthesis of nano zerovalent nickel (nZVN) by a simple grinding reduction method. The obtained nZVN was characterized with XRD, SEM, EDS and BET surface area. The results confirms the formation of nZVN and the active particle cluster size ranges from 100 to 200 nm. N₂ adsorption isotherms revealed that the formation mesoporous cluster of nZVN with good surface area. The adsorption of Cr(VI) using nZVN showed 96% removal efficiency for 10 ppm concentration, and even up to 98% when the temperature is slightly raised to 36 °C (309 K). The removal efficiencies of Cr by zerovalent nickel was well fitted by the Langmuir-Hinshelwood first order reaction kinetic model with deceptive rate constant values of 0.6699, 0.7956 and 1.0251 min^-1 at temperature 200, 303 and 309 K, respectively. In total, our studies suggest that nanoscale zerovalent iron is a capable material for Cr(VI) remediation from groundwater.