Adsorbate
Stock solution was prepared by dissolving 3.798 g of Cu(NO3)2·3H2O in 250 mL of deionized water, diluted to 1 L in a volumetric flask with double distilled water procured from Millipore ELIX-10 unit. Test solutions were prepared by progressive dilution of stock solution of copper with double distilled water and the pH was adjusted to the desired value by using 0.1 N HNO3 or 0.1 N NaOH solutions. All chemicals used were of analytical grade.