Recovery of Gold from Gold Plating Industry Wastewater Using an Agricultural Waste: Hard Shell of Apricot Stones

Activated carbons are extremely versatile adsorbents for major industrial significance, especially for metal ions recovery from wastewaters. In this study, the activated carbon prepared from the hard shell of apricot stones, an agricultural solid, which was used for the gold recovery from gold-plating wastewater is investigated. Activated carbon was produced by chemical activation with phosphoric acid. Recovery parameters such as adsorbent dose, the particle size of the activated adsorbent, pH and the agitation speed of mixing were studied. The equilibrium data fit well with the Freundlich isotherm model. A Langmuir isotherm model has been used to obtain thermodynamic parameters. The results showed that under the optimum operating conditions, more than 98 per cent of the gold was recovered by activated carbon after only 3 hours. It was found that the activated hard shell of apricot stones could be used as an effective adsorbent for gold recovery from wastewaters.