Banana Peel Carbon that Containing Functional Groups Applied to the Selective Adsorption of Au(III) from Waste Printed Circuit Boards

This paper reports a kind of banana peel carbon (BPC) containing -OH, -NH2 functional groups which prepared through controlling carbonization temperature and its application on the selective adsorption of gold from waste printed circuit boards (PCBs). The adsorption of BPC for Au(III) reached equilibrium in 30 min and the adsorption of Au(III) was favorable at pH 2.5. Meanwhile, the adsorption isotherm showed the maximum adsorption capacity of 801.7 mg/g for Au(III). The results displayed that BPC had a strong selectivity for Au(III) and a negligible affinity to base metal ions, such as Cu(II), Ni(II), Fe(III) and Pb(II). The BPC adsorbent, which absorbed gold, can be recovered completely by HCl-thiourea solution.