Removal of copper from aqueous solution with phosphate rocks

To investigate the role and effects of the medium-grade phosphate rocks on Cu²⁺ removal in aqueous solution, three phosphate rocks (PRs) were selected from Hubei Province and the characteristics of Cu²⁺ removal were studied using batch experiment with phosphate rocks under different conditions in aqueous solution. The results showed: that the Cu²⁺ in aqueous solution was effectively removed by the PRs, the effects of Cu²⁺ removal were related to the composition of PRs, solution pH, ionic strength, Cu²⁺ concentration, coexisting metal ions such as Cd²⁺. With the increase of total content P of PRs, the pH of solution, the ionic strength, and the decrease of coexisting metal ions, the amount of Cu²⁺ adsorption in PRs increased. Further studies, using FTIR and XRD, have shown that Cu²⁺ combined with PRs on their surfaces, but did not form new compounds. These findings have an important impact on the rational development and application of phosphate rocks as adsorbents, and heavy metals treatment in wastewater in the future.