Chapter 4
Investigation into the Adsorption
of Cadmium and Lead by Polyaniline
Grafted Cross-Linked Chitosan Beads
from Aqueous Solution
Abstract This research explored the enhancement of chitosan beads by crosslinking and grafting to use the grafted beads to extract cadmium and lead from
polluted water. XRD and SEM characterized the beads to bear evidence of positive
cross-linking and grafting. Batch investigation was conducted with regards to the
parameters of adsorption such as pH, initial concentration, contact time and adsorbent dose. Equilibrium data were collected from the adsorption investigation, and the
data were compared with the isotherm models including Langmuir and Freundlich.
The maximum adsorption potential for cadmium and lead ions was found to be,
respectively, 145 mg/g and 114 mg/g at a temperature of 45 °C from the Langmuir model. Thermodynamic parameters such as Gibbs free energy change (G
o ),
enthalpy change (H
o ) and entropy shift (S
o ) were subsequently determined and
the findings illustrate that polyaniline adsorption of cadmium and lead ions on the
produced adsorbent (GXCS) is spontaneous and endothermic in nature. The firstorder pseudo- and second-order pseudo-models have been used for the study of
kinetic data for both metal ions. The data match well with the second-order pseudomodel. Over five consecutive cycles of adsorption/desorption, the GXCS filled with
cadmium and lead ions was measured. Nevertheless, 0.5 M HCl was successfully
used among the eluents examined in desorbing the adsorbent expended and among
the eluents that was investigated 0.5 M HCl was successfully used in desorbing the
spent adsorbent and a percentage desorption of 98.94 and 97.50% was acquired for
cadmium and lead ions correspondingly, at a desorption time of 180 min.
4.1 Introduction
The pollution of surface by heavy metal ions has been a problem harming the environment in the last decades. The main causes of these heavy metals are the alreadyrising factories that generate different forms of physicochemical contaminants that
enter the water [1, 2]. Rising levels of these metals in water pose severe hazard to
health because they are not environmentally friendly [3, 4]. For example, cadmium
causing the preceding potential health risks, renal damage, tai-tai, hypertension,
emphysema and testicular atrophy is manufactured by economic sectors including
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
E. Igberase et al., Enhanced Chitosan Material for Water Treatment,
Engineering Materials, https://doi.org/10.1007/978-3-030-71722-3_4
71
Investigation into the Adsorption
of Cadmium and Lead by Polyaniline
Grafted Cross-Linked Chitosan Beads
from Aqueous Solution
Abstract This research explored the enhancement of chitosan beads by crosslinking and grafting to use the grafted beads to extract cadmium and lead from
polluted water. XRD and SEM characterized the beads to bear evidence of positive
cross-linking and grafting. Batch investigation was conducted with regards to the
parameters of adsorption such as pH, initial concentration, contact time and adsorbent dose. Equilibrium data were collected from the adsorption investigation, and the
data were compared with the isotherm models including Langmuir and Freundlich.
The maximum adsorption potential for cadmium and lead ions was found to be,
respectively, 145 mg/g and 114 mg/g at a temperature of 45 °C from the Langmuir model. Thermodynamic parameters such as Gibbs free energy change (G
o ),
enthalpy change (H
o ) and entropy shift (S
o ) were subsequently determined and
the findings illustrate that polyaniline adsorption of cadmium and lead ions on the
produced adsorbent (GXCS) is spontaneous and endothermic in nature. The firstorder pseudo- and second-order pseudo-models have been used for the study of
kinetic data for both metal ions. The data match well with the second-order pseudomodel. Over five consecutive cycles of adsorption/desorption, the GXCS filled with
cadmium and lead ions was measured. Nevertheless, 0.5 M HCl was successfully
used among the eluents examined in desorbing the adsorbent expended and among
the eluents that was investigated 0.5 M HCl was successfully used in desorbing the
spent adsorbent and a percentage desorption of 98.94 and 97.50% was acquired for
cadmium and lead ions correspondingly, at a desorption time of 180 min.
4.1 Introduction
The pollution of surface by heavy metal ions has been a problem harming the environment in the last decades. The main causes of these heavy metals are the alreadyrising factories that generate different forms of physicochemical contaminants that
enter the water [1, 2]. Rising levels of these metals in water pose severe hazard to
health because they are not environmentally friendly [3, 4]. For example, cadmium
causing the preceding potential health risks, renal damage, tai-tai, hypertension,
emphysema and testicular atrophy is manufactured by economic sectors including
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
E. Igberase et al., Enhanced Chitosan Material for Water Treatment,
Engineering Materials, https://doi.org/10.1007/978-3-030-71722-3_4
71