Effect of carbonaceous matter on copper behavior in bioleaching from waste printed circuit boards

Abstract

In this paper, the effects of humic acid, activated carbon and graphite on the bioleaching behavior of copper from waste printed circuit boards (WPCBs) with HQ0211 bacteria strain have been investigated. The compatibility test and the optimal additive amount of carbonaceous matter and the mechanism analysis were studied. It was demonstrated that humic acid has good compatibility with microorganisms. Humic acid can significantly promote the dissolution rate of copper with appropriate amount. The addition of activated carbon and graphite could inhibit the growth of bacteria. And the inhibition was weakened on the bioleaching process. The optimal condition of bioleaching copper was WPCBs 50 g L-1, initial pH 1.5, bacterial leaching time 7 days, the leaching rate of copper increased by 11.08%, 8.71% and 6.84% respectively in the experimental group with proper dosage of humic acid, activated carbon and graphite.