Removal of nickel from aqueous solution by using corncob as adsorbent

Abstract

Heavy metal deposition in the environment is increasing day by day as a result of the rapid growth of the industrial sector and massive anthropogenic activities. Among numerous heavy metals, nickel is the 5th greatest copious component on the planet. Though numerous conventional treatments are available to remediate nickel-contaminated water, including electrochemistry, precipitation, flocculation, ion exchange, coagulation, membrane filtration, and adsorption, each has some or all of the following drawbacks in terms of cost and efficiency in removing metal ions from water. Among all methods, the adsorption method was found to be the most cost-effective and efficient at removing metal ions from water. Adsorption is a highly efficient and cost-effective method of extracting nickel ions from water that involves surface phenomena. The primary goal of this paper is to identify the indigenous adsorbent for a batch study in extracting nickel ions from an aqueous solution. Corncob is used as a low-cost agro-based adsorbent in this study to remove nickel ions from an aqueous medium. Under batch methodology, the effect of several major adsorption operating parameters has been considered and optimized. It was discovered that the optimum adsorbent dose was 1.5 g/50 ml, that equilibrium was achieved in 120 min, and that better adsorption at pH 8 was obtained. Freundlich, Langmuir, and Temkin isotherm models were used to correlate sorption data. The result demonstrates that the Langmuir adsorption model fits best when compared to other adsorption isotherm models, with R2 = 0.9781 and adsorption capacity, Q0 = 0.0517 mg/g. Adsorption kinetics are discussed to investigate the rate of nickel ion uptake on the adsorbent. A kinetic study revealed that the pseudo-second-order model was better fitted than pseudo-first-order, with R2 = 0.9999.