Removal of Nickel from aqueous solution by using clay brick

Abstract

Nowadays, the search for low-cost adsorbent has become a trend as it is less expensive than commercial activated carbon. Generation of nickel in wastewater is produced in large quantity from many industrial and commercial applications such as nickel electroplating and nickel-zinc batteries for hybrid vehicles. As a consequence, human and the environment are in great risk to be exposed to the potentially dangerous heavy metal. In this research, clay brick from demolition wastes was studied as a low-cost adsorbent for nickel removal from aqueous solution. The raw clay brick was chemically modified by using 0.1 M sodium hydroxide solution. The research aims to determine optimum pH, adsorbent dosage, and contact time to enhance adsorption of nickel by clay brick and explain the adsorption behaviour using isotherm and kinetic models. It was discovered that pH 7 and 300 g/L of adsorbent dosage were optimum for high nickel removal (95.5 %) from aqueous solution. Two hours contact time was required for total removal of 20 mg/L Ni (II) and the time increased with higher nickel concentration. The results indicated that Langmuir model fit the data better than Freundlich and kinetic adsorption was best described by the Pseudosecond order kinetic model.