Modified orange peels for the recovery of silver from waste printed circuit boards

Abstract

In this study, it was focused on the silver adsorption from PCB by biosorbents derived from orange peels. In this content, orange peels (OP) were modified by different methods including saponification with NaOH (OP-S), hydroxypropylation with propylene oxide (OP-H) and crosslinking with sodium trimetaphosphate and sodium tripolyphosphate (OP-C) in order to increase the adsorption capacity. Firstly, adsorption tests on the Ag model solutions were carried out by using the native/modified orange peels to determine the optimum adsorption conditions. Then, PCB was pyrolyzed in a fixed bed stainless steel reactor to obtain an only metal containing solid product. After then, metals were leached from the solid product. At the last stage, adsorption studies were realized on leach solution under optimum adsorption conditions.