259
industrial wastewater. Chitosan and gelatin spherical hydrogel particles were prepared by inverse emulsion method and revealed that for single ion solution, it shows
maximum adsorption efficiency of 98% for Hg
+2
ion whereas 73–94% for multiple
ions such as Pb
+2
, Cd
+2
, Hg
+2
, and Cr
+3
. Some of the chitosan composite with its
application are enlisted in Table 10.6.
10.3.5 Coal
Raw hard coals are cheap and exist in large deposits in many countries. They do not
lose their properties after use and also represents a highly calorific fuel. Thus raw
hard coals are one of the promising adsorbents. The adsorption of gases such as
CO 2 , CH 4 , and acetylene on raw hard coals has been widely studied (Li et al. 2010;
Gensterblum et al. 2014). The application of raw hard coals as low-cost adsorbents
for water treatment has been described in only a few works for the removal of heavy
metal ions (Lakatos et al. 2001, 2002), dyes (McKay et al. 1999; Venkata Mohan
et al. 2002). The most important parameters affecting the adsorption process of
metal ions by coal include pH and ionic strength.
Table 10.6 Performance of chitosan as adsorbent for remediation of toxic metal-contaminated
wastewater
Adsorbent
Adsorbate
Adsorption capacity
(mg/g)
References
Chitosan/alumina
Cr(VI)
153
Boddu et al. (2003)
Chitosan/perlite
Cu(II)
128.20
Swayampakula et al.
(2009)
Chitosan/perlite
Cu(II)
196.07
Kalyani et al. (2005)
Chitosan/cotton fibers
Hg(II)
104.31
Qu et al. (2009)
Magnetic chitosan
Cr(VI)
69.40
Huang et al. (2009)
Chitosan/magnetite
Pb(II)
63.30
Tran et al. (2010)
Chitosan/magnetite
Ni(II)
52.55
Tran et al. (2010)
Chitosan/calcium alginate Ni(II)
222.2
Vijaya et al. (2008)
Chitosan/silica
Ni(II)
254.3
Vijaya et al. (2008)
Chitosan/PVC
Ni(II)
120.5
Popuri et al. (2009)
Chitosan/PVA
Cd(II)
142.9
Kumar et al. (2009)
Fe 3 O 4 /chitosan films
Pb(II)
114.9
Lasheen et al. (2016)
Chitosan nanoparticles
Pb(II)
398.0
Qi and Xu (2004)
Chitosan nanorods
Cr(VI)
323.6
Sivakami et al. (2013)
Cross-linked chitosan
Hg(II)
269
Zhou et al. (2010)
Coconut shell/chitosan
Zn(II)
60.41
Amuda et al. (2007)
PVC polyvinyl chloride, PVA polyvinyl alcohol
10 Heavy Metal Removal by Low-Cost Adsorbents
industrial wastewater. Chitosan and gelatin spherical hydrogel particles were prepared by inverse emulsion method and revealed that for single ion solution, it shows
maximum adsorption efficiency of 98% for Hg
+2
ion whereas 73–94% for multiple
ions such as Pb
+2
, Cd
+2
, Hg
+2
, and Cr
+3
. Some of the chitosan composite with its
application are enlisted in Table 10.6.
10.3.5 Coal
Raw hard coals are cheap and exist in large deposits in many countries. They do not
lose their properties after use and also represents a highly calorific fuel. Thus raw
hard coals are one of the promising adsorbents. The adsorption of gases such as
CO 2 , CH 4 , and acetylene on raw hard coals has been widely studied (Li et al. 2010;
Gensterblum et al. 2014). The application of raw hard coals as low-cost adsorbents
for water treatment has been described in only a few works for the removal of heavy
metal ions (Lakatos et al. 2001, 2002), dyes (McKay et al. 1999; Venkata Mohan
et al. 2002). The most important parameters affecting the adsorption process of
metal ions by coal include pH and ionic strength.
Table 10.6 Performance of chitosan as adsorbent for remediation of toxic metal-contaminated
wastewater
Adsorbent
Adsorbate
Adsorption capacity
(mg/g)
References
Chitosan/alumina
Cr(VI)
153
Boddu et al. (2003)
Chitosan/perlite
Cu(II)
128.20
Swayampakula et al.
(2009)
Chitosan/perlite
Cu(II)
196.07
Kalyani et al. (2005)
Chitosan/cotton fibers
Hg(II)
104.31
Qu et al. (2009)
Magnetic chitosan
Cr(VI)
69.40
Huang et al. (2009)
Chitosan/magnetite
Pb(II)
63.30
Tran et al. (2010)
Chitosan/magnetite
Ni(II)
52.55
Tran et al. (2010)
Chitosan/calcium alginate Ni(II)
222.2
Vijaya et al. (2008)
Chitosan/silica
Ni(II)
254.3
Vijaya et al. (2008)
Chitosan/PVC
Ni(II)
120.5
Popuri et al. (2009)
Chitosan/PVA
Cd(II)
142.9
Kumar et al. (2009)
Fe 3 O 4 /chitosan films
Pb(II)
114.9
Lasheen et al. (2016)
Chitosan nanoparticles
Pb(II)
398.0
Qi and Xu (2004)
Chitosan nanorods
Cr(VI)
323.6
Sivakami et al. (2013)
Cross-linked chitosan
Hg(II)
269
Zhou et al. (2010)
Coconut shell/chitosan
Zn(II)
60.41
Amuda et al. (2007)
PVC polyvinyl chloride, PVA polyvinyl alcohol
10 Heavy Metal Removal by Low-Cost Adsorbents