Nickel removal from electroless wastewater by using coagulation flocculation and ion exchange

Abstract

A massive growth in the industry of electroplating is associated with an increase in the quantity of nickel found in surface water and groundwater. This study focused on the removal of nickel concentration from organic solid waste stream of electroplating industry by using coagulation flocculation and ion exchange methods. In this study, various types of coagulants such as chitosan, WPC 6001, ferric chloride and polyacrylamide were tested to determine the best coagulant for removal of nickel, total suspended solid, chemical oxygen demand and turbidity. The effects of process variables such as pH and coagulant dosage on the performance of these coagulants were also investigated. Polyacrylamide (PAA) was found to be the best coagulant with percentage of 96.6%, 47.2%, 99.6% and 99.6% for removals of nickel, chemical oxygen demand, total suspended solid and turbidity respectively at the pH value of 10 and 1.6 mL/L dosage. From Response Surface Methodology (RSM), the optimal conditions for removal of nickel were found to be at pH 10.46 and 1.64 ml/L PAA dosage. Chelating resin was found to be the best resin with 99.6% nickel removal at pH value of 4. The treated wastewater’s nickel content meets Standard A of the Malaysian Environmental Standard.