Batch adsorption experiments were carried out by shaking 0.5 g of the Kyanite (mesh 50)
with 50 ml aqueous Cu(II) solution of 20–100 mg l−1 concentration at various pHs (1–12)
and at temperature of 30◦C in several stoppered bottles for retention times varying from 5
to 30 min using a temperature controlled shaker. The study of adsorbent doses was carried
out by varying the amount of adsorbent (0.2–1 g). At the end of the predetermined time
interval, the adsorbent was removed by the filtration and the equilibrium concentration
was determined in the filtrate by atomic absorption spectrophotometry (model GBC-902,
Australia) using an air acetylene flame. The amount of metal ions adsorbed on the Kyanite
was calculated by subtracting final concentration in solution from initial concentration. The
effect of pH on the adsorption of Cu(II) was studied as follows: 100 ml Cu(II) solution
(50 mg l−1) was placed in a beaker and the pH of the solution was adjusted by adding 0.5M
HNO3 or 0.1M NaOH. The concentration of Cu(II) in this solution was then determined
(initial concentration). An aliquot (50 ml) of this solution was placed in a conical flask and
treated with 0.5 g of adsorbent and after equilibrium, the final concentration of Cu(II) was
determined.