Adsorption of Pb, Cd, Zn, Cu and Hg ions on Formaldehyde and Pyridine Modified Bean Husks|
Adediran, G.O.; Tella, A.C. & Mohammed, H.A.
Adsorption of Pb(II), Cd(II), Zn(II), Cu(II) and Hg(II) ions on formaldehyde and Pyridine
modified bean husks were determined. The adsorption capacity of formaldehyde modified bean husks (mg/g)
was: Pb2+, 5.01; Cd2+, 3.63; Zn2+, 2.18; Hg2+, 1.82; Cu2+, 1.58 and that of pyridine modified bean husk was: Hg2+,
6.92; Cd2+, 3.63; Pb2+, 2.64; Zn2+, 2.48; Cu2+, 1.91. The Freundlich equation parameter 1/n for the metal ions
were found to be less than unity which indicates that adsorption of metals on bean husks have increased as a
result of modification. The calculated value from Freundlich adsorption parameter (KF) and Langmuir adsorption
parameter (qmax) showed that the adsorption capacities of the metal ions are in order of Pb2+ > Cd2+ > Zn2+ > Hg2+
> Cu2+ for formaldehyde modified bean husks and Hg2+ > Cd2+ > Pb2+ > Zn2+ > Cu2+ for pyridine modified bean
husks. The binding capacity study showed that the formaldehyde modified bean husks could be employed in the
removal of Pb2+ and Zn2+ from industrial effluent especially in the battery manufacturing, paints and dyes
industries. This study also indicates that the pyridine modified bean husk could remove Hg2+ better than the
formaldehyde modified bean husk in the printing and minting industrial effluent.