Efficient removal of cu(Ii) and zn(ii) from aqueous solution and real acid mine drainage by natural vermiculite and kaolinite

In this study, the removal of Cu(II) and Zn(II) by new natural native vermiculite and kaolinite from aqueous solution and real acid mine drainage (AMD) was investigated. The adsorbents were characterized using X-ray fluorescence, X-ray diffraction and Fourier-transform infrared spectroscopy analysis. The effect of pH, contact time, temperature, adsorbent dose, particle size, and ini-tial metal concentration were determined in a batch experiment. Major chemical components of the vermiculite were CaO (43.31) and SiO2 (13.5) and for kaolinite were SiO2 (75.8) and Al2 O3 (14.7). The most important functional group of vermiculite and kaolinite was O�H as an active site for binding positively charged cation. The removal efficiencies of Cu(II) and Zn(II) increased by increasing pH from 2 to 6 and increasing the temperature from 25°C to 35°C. The most removal efficiency by using vermiculite in contact time 45 min were 81 for Cu(II) and 74 for Zn(II) and for kaolinite were 67 and 76 for Cu(II) and Zn(II) in 30 and 45 min, respectively. The adsorption experiment data indicated that the Langmuir isotherm and the pseudo-second-order kinetic were more suitable for describing the adsorption process. Experiments on the real AMD sample showed that Cu(II) removal efficiency by vermiculite and kaolinite was 82 and 71 and for Zn(II) was 65 and 56, respectively. Therefore, these natural native adsorbents are able to remove Cu(II) and Zn(II) from the AMD. © 2020 Desalination Publications. All rights reserved