It has been observed that the percentage of copper
adsorption increased with increasing agitation speed due to
the proper contact between the metal ions in solution and the
adsorbents binding sites that promotes effective transfer of
copper ions to the adsorbents sites. Results indicated that the
Cu(II) adsorption by chicken eggshells reached almost 100% at
350 rpm. At lower speed, the adsorbent will accumulate at
bottom and result in burial of various active sites under the
above layers of adsorbent [8].