Adsorption and desorption of zinc and copper in acid mine drainage onto synthesized zeolite from coal fly ash

Abstract

Synthetic zeolite is considered a more effective adsorbent due to its high purity and high removal efficiency. On the other hand, acid mine drainage contains various metal ions, such as zinc, copper, iron, and manganese which are toxic for the ecosystem in a certain concentration. One of the solutions to remove these metal ions is through adsorption. Therefore, the study of adsorption and desorption of zinc and copper onto synthetic zeolite was conducted. The synthetic zeolite was synthesized from coal fly ash and the acid mine drainage was prepared artificially. The adsorption experiment was carried out using a batch system. NaCl, H2SO4, and HNO3 were used as desorption agent. The adsorption studies revealed that the removal efficiency of both Zn2+ and Cu2+ onto the studied adsorbent decrease with the increase of adsorbate concentration. While the adsorption selectivity for multi-system synthetic AMD solution by the studied adsorbent were found to the order of Fe2+> Cu2+> Zn2+> Mn2+.After being reused three times, the synthetic zeolite shows a decrease in for Zn2+ and Cu2+ adsorption efficiency of about 10%. Furthermore, the desorption study shows the ineffective use of NaCl, H2SO4, and HNO3 as desorption agents in this study.