Efficacy of Nano-Clay Derived from Egyptian Alluvial Soils for Cu(II) Removal from Aqueous Solutions.

The objectives of this study were to prepare and characterize nano-clay particles from an alluvial Nile Delta Egyptian soil and to understand and evaluate its efficacy for removal of Cu(II) from aqueous solutions. Nano-clay particles were prepared by ball milling of the clay soil fraction and their nano scale was confirmed by SEM image analysis. The XRD peaks revealed the dominance of montmorillonite clay minerals in soil clay and nano-clay adsorbents. FTIR features indicated the characteristic surface functional groups of smectite clays for both adsorbents. Cu(II) adsorption by the two adsorbents tended to increase with increasing initial Cu(II) concentration (10 to 150 mg L-1), adsorbent dosage (0.05, 0.1, 0.25, 0.5, 1 g/100 ml) and pH (4, 7 and 9). The two adsorbents showed high buffering capacity of the solution pH. Nano-clay adsorbent could remove higher amounts of Cu(II) from aqueous solutions (62%) than soil clay (45%) at initial Cu(II) concentration of 50 mg L-1 in the aqueous solution. Equilibrium time of 30 min. was achieved under the various experimental conditions which suggests ion exchange mechanism. Data of adsorption isotherms and kinetics were statistically best fitted to pseudo-second order and Langmuir models, respectively. [ABSTRACT FROM AUTHOR]