Development of an eco-friendly treatment method for e-waste

Abstract

E-Waste, the wastes arising from discarded electronic components, is one of the fastest growing waste streams which contain a number of hazardous substances. It is a complex mixture of toxic metals and polymers which, if disposed without proper treatment, can have major adverse impacts on the environment. The toxic metals can leach out and cause ecological and public health impacts. In the present study, an environment friendly method has been developed, which allows the recovery of the toxic metals copper (Cu), Lead (Pb) and Zinc (Zn) from printed circuit boards (PCB). In this process, the metals were extracted from the finely ground and sieved PCB wastes by a sequential extraction process using 2N Hydrochloric acid. Stage wise extraction followed by pH adjustment under different conditions was able to selectively enrich Pb from other metals. From a screening of natural waste materials, alkali treated palm leaf powder was selected as a biosorbent to remove the metals from the acid extract. Complete removal of Pb and a high removal (82%) of Cu were observed at a biosorbent dose of 100 g/l. Both Freundlich and Langmuir isotherms fitted the batch adsorption data well.