1. Adsorption studies of Cu(II), Zn(II), Ni(II) and Cr(VI) using Kyanite as an adsorbent
have shown the percent adsorption in the order of Cu(II) > Ni(II) > Cr(VI) > Zn(II).
2. Equilibrium was attained in 30 min and the maximum adsorption of Cu(II) was observed
at initial concentration of 20 mg l−1.
3. Complete adsorption is possible at pH 8. The degree (%) of adsorption increases with
increase in adsorbent dose (0.2–1 g) and decrease in particle size of Kyanite.
4. The efficiency of adsorbent for copper removal in presence of other ions (usually present
in electroplating wastewater) has been studied and it can be concluded that total (100%)
adsorption is possible in presence of 100 mg l−1 NaHCO3 in 50 mg l−1 of Cu(II) solution.
5. The utility of Kyanite has been demonstrated by removing Cu(II) along with other metal
ions present in electroplating wastewater. A concentration of Cu(II) ions as high as
8mg l−1 in the waste can be reduced to 1.5 mg l−1. The adsorbed Cu(II) ions could be
recovered with 0.05M HCl. However, the percent recovery of Cu(II) is increased by
column operation (80%) under similar conditions of elution.