The overall trend of heavy metal removal (%) using sonication
method followed the order Pb(II) > Ni(II) > Cu(II) > Cd(II) > Mn(II)
(Fig. 3). This removal was found to be directly proportional to
the size of the metal ions, Pb(II) being the largest metal ion
among the metals studied was highly removed and Mn2+ is the
smallest metal ion, hence was removed the least.