Removal of Cu(II) ions from aqueous solution by fatty hydroxamic acids immobilized onto bentonite

Abstract

Abstract The mining business in Indonesia has a large contribution to economic growth and the supplies of domestic minerals. However, if the mining businessis conducted illegally and does not use the good mining practice, it will not only harm the country but also risk endangering human safety due to environmental damage caused. In gold mining process, only the main metal, that is gold, is taken while the other metal is discharged into the sewer as waste.One of the metal ions to be waste is copper ion, Cu(II) ion. In this study, removal of Cu(II) ions from illegal gold mining waste was carried out using fatty hydroxamic acids (FHA) immobilized onto bentonite.The FHA used is enzymatically synthesized from Jatropha curcas L. kernel oil. The effects of Cu(II) ion pH and FHA concentration on copper removal have been investigated.The presented results indicated that the extraction of Cu(II) ion was very sensitive to the copper ion pH and extractant concentration. The optimum pH of Cu(II) ion adsorption by FHA-Bentonite (FHA-Bent) is pH 5.A quantitative recovery of Cu(II) ion from FHA-Bent was obtained using 10% HNO3 solutions as eluent with a pre-concentration factorupto 60.