131
Grafted Cellulose
Chemical modifications followed by grafting enhance the cation exchange capacity
of cellulose (Anirudhan and Senan 2011). Grafting of polyacrylonitrile and polyacrylic acid on holocellulosic materials was done at various levels, and the modified
cellulose was attempted for Cu(II), Cd(II), and Pb(II) eradication by researchers
(Okieimen and Ebhoaye 1986). The metal binding efficiency of the adsorbent was
increased with the level of graft polymers. Others (He et al. 1999) treated alkaloid
and aged cotton with CS 2 and CaCO 3 , and then gradually, potassium oleate and
chlorobenzene was added in sequence and heated to synthesis the cellulose xanthate
viscose beads. The beads were filtered and washed to attain macroporous sphericalshaped cellulose, and it was further activated with epichlorohydrin and Tween-20.
White macroporous spherical-shaped cellulose activated by epichlorohydrin was
collected by extraction with acetone. The beads were then modified by 1,5- diamino
ethyl- 3-hydroxy-1,5-diazacycloheptane, and finally the modified cellulose beadbased biosorbents were obtained. The modified beads spontaneously removed copper and lead with excellent performance. Guclu et al. studied the influence of graft
chains on four different types of cellulosic copolymers; synthesized with a variety
of percentages of polyacrylic acid in the presence of other chemicals. The grafted
cellulose treated Pb(II), Cu(II), and Cd(II) ions successfully. The reaction rate
decreased with increase in grafting percentages of polyacrylic acid, but the overall
metal adsorption enhanced (Guclu et al. 2003). Radioactive isotopes were used by
others to graft polymers to the cellulose by irradiation technique (Nasef and Hegazy
2004). By grafting acrylamide on banana stalk, a new adsorbent was prepared by
Shibi and Anirudhan and was applied for cadmium and lead treatment (Shibi and
Anirudhan 2006). The modified adsorbent showed creditable adsorption capacity
and the equilibrium reached in 3 h. The reaction obeyed pseudo-second-order rate.
Cellulose Composites
Cellulose composites are prepared by combining cellulose with other materials.
Composite materials have better adsorption capacity compared to its constituting
materials and have diverse applications and provide a solution for many engineering
applications in wastewater treatment. Researchers (Sun et al. 2009) prepared a biocomposite by blending chitosan with cellulose, and the composite material was
effective in removal of most of the heavy metals, such as Cu(II), Zn(II), Cr(VI),
Ni(II), and Pb(II), in freeze-drying condition. Kumar et al. synthesized cellulose–
montmorillonite composite material by reacting cellulose with sodium montmorillonite and applied the composite for Cr(VI) remediation (Kumar et al. 2011). The
reaction followed second-order kinetics and the composite material had ten times
regeneration capacity. The Langmuir adsorption capacity was 22.2 mg g
−1
.Another
group of scientists (Gandhi et al. 2011) prepared nano-hydroxyapatite compound by
reaction with Ca(NO 3 ) 2 and ammonium dihydrogen phosphate at pH more than 10.
The precipitate was washed and dried. This nano-hydroxyapatite was then
5 Cellulose-Based Adsorbents for Heavy Metal Removal
Grafted Cellulose
Chemical modifications followed by grafting enhance the cation exchange capacity
of cellulose (Anirudhan and Senan 2011). Grafting of polyacrylonitrile and polyacrylic acid on holocellulosic materials was done at various levels, and the modified
cellulose was attempted for Cu(II), Cd(II), and Pb(II) eradication by researchers
(Okieimen and Ebhoaye 1986). The metal binding efficiency of the adsorbent was
increased with the level of graft polymers. Others (He et al. 1999) treated alkaloid
and aged cotton with CS 2 and CaCO 3 , and then gradually, potassium oleate and
chlorobenzene was added in sequence and heated to synthesis the cellulose xanthate
viscose beads. The beads were filtered and washed to attain macroporous sphericalshaped cellulose, and it was further activated with epichlorohydrin and Tween-20.
White macroporous spherical-shaped cellulose activated by epichlorohydrin was
collected by extraction with acetone. The beads were then modified by 1,5- diamino
ethyl- 3-hydroxy-1,5-diazacycloheptane, and finally the modified cellulose beadbased biosorbents were obtained. The modified beads spontaneously removed copper and lead with excellent performance. Guclu et al. studied the influence of graft
chains on four different types of cellulosic copolymers; synthesized with a variety
of percentages of polyacrylic acid in the presence of other chemicals. The grafted
cellulose treated Pb(II), Cu(II), and Cd(II) ions successfully. The reaction rate
decreased with increase in grafting percentages of polyacrylic acid, but the overall
metal adsorption enhanced (Guclu et al. 2003). Radioactive isotopes were used by
others to graft polymers to the cellulose by irradiation technique (Nasef and Hegazy
2004). By grafting acrylamide on banana stalk, a new adsorbent was prepared by
Shibi and Anirudhan and was applied for cadmium and lead treatment (Shibi and
Anirudhan 2006). The modified adsorbent showed creditable adsorption capacity
and the equilibrium reached in 3 h. The reaction obeyed pseudo-second-order rate.
Cellulose Composites
Cellulose composites are prepared by combining cellulose with other materials.
Composite materials have better adsorption capacity compared to its constituting
materials and have diverse applications and provide a solution for many engineering
applications in wastewater treatment. Researchers (Sun et al. 2009) prepared a biocomposite by blending chitosan with cellulose, and the composite material was
effective in removal of most of the heavy metals, such as Cu(II), Zn(II), Cr(VI),
Ni(II), and Pb(II), in freeze-drying condition. Kumar et al. synthesized cellulose–
montmorillonite composite material by reacting cellulose with sodium montmorillonite and applied the composite for Cr(VI) remediation (Kumar et al. 2011). The
reaction followed second-order kinetics and the composite material had ten times
regeneration capacity. The Langmuir adsorption capacity was 22.2 mg g
−1
.Another
group of scientists (Gandhi et al. 2011) prepared nano-hydroxyapatite compound by
reaction with Ca(NO 3 ) 2 and ammonium dihydrogen phosphate at pH more than 10.
The precipitate was washed and dried. This nano-hydroxyapatite was then
5 Cellulose-Based Adsorbents for Heavy Metal Removal