30
2 Thermodynamics, Kinetics and Desorption Studies …
2.3.2 Adsorption Kinetics
This investigation was carried out by introducing 6 mg of G/CR-CS into 100 mL
of metal ions solution in a sequence of 250 mL Erlenmeyer flasks having initial
concentration of 40 mg/L. The Erlenmeyer flask was put in a Labcon incubator to
achieve equilibrium, the solution was shaken at 150 rpm, and the temperature set
at 45 °C. The samples were taken at 10–60 min intervals. This process has been
conducted for each of the ions. The investigation was conducted in triplicate, and
this study provided the mean result.
At optimum, 2.1, was used to measure the adsorption power, q e (mg/g), while
2.2 was applied in determining the percentage removal of metal ions from the single
component mixture.
q e =
(C o − C e ) × V
M
(2.1)
%R =
(C o − C e )
C o
× 100
(2.2)
where q e (mg/g) is the adsorption potential for equilibrium, C o and C e are the initial
and equilibrium concentration (mg/L) of heavy metal ion in solution, whereas V
(mL) is the volume and M (g) is the mass of G/CR-CS, respectively.
2.4 Result and Discussion
2.4.1 Classification Result
The three collection of chitosan beads (pure CS, CR-CS and G/CR-CS) were
classified so as to determine most of their physical and chemical properties.
2.4.1.1 FTIR Analysis
The FTIR spectra were presented in Fig. 2.3, and it shows the transformation in the
functional groups of the modified beads. A typical FTIR spectrum of pure chitosan
(CS) showed characteristic bands at 1029, 1195, 1650, 1734, 2939 and 3324 cm
−1 .
While the sharp intense peak at 1029 cm
−1 was attributed to C–O stretching vibrations
[20][1][1][2][2][2][1], the peaks around 1195 cm
−1 were assigned to C–N stretching
vibrations of amine functional group. Peaks at 1650 and 1734 cm
−1 were attributed
to C=O stretching vibrations of ketone and amide, respectively. The IR spectra peaks
showed at 2939 cm
−1 were assigned to asymmetric –CH 2 stretching [21, 25]. Finally,
the peak at 3324 cm
−1 was reported to indicate the presence of exchangeable protons
2 Thermodynamics, Kinetics and Desorption Studies …
2.3.2 Adsorption Kinetics
This investigation was carried out by introducing 6 mg of G/CR-CS into 100 mL
of metal ions solution in a sequence of 250 mL Erlenmeyer flasks having initial
concentration of 40 mg/L. The Erlenmeyer flask was put in a Labcon incubator to
achieve equilibrium, the solution was shaken at 150 rpm, and the temperature set
at 45 °C. The samples were taken at 10–60 min intervals. This process has been
conducted for each of the ions. The investigation was conducted in triplicate, and
this study provided the mean result.
At optimum, 2.1, was used to measure the adsorption power, q e (mg/g), while
2.2 was applied in determining the percentage removal of metal ions from the single
component mixture.
q e =
(C o − C e ) × V
M
(2.1)
%R =
(C o − C e )
C o
× 100
(2.2)
where q e (mg/g) is the adsorption potential for equilibrium, C o and C e are the initial
and equilibrium concentration (mg/L) of heavy metal ion in solution, whereas V
(mL) is the volume and M (g) is the mass of G/CR-CS, respectively.
2.4 Result and Discussion
2.4.1 Classification Result
The three collection of chitosan beads (pure CS, CR-CS and G/CR-CS) were
classified so as to determine most of their physical and chemical properties.
2.4.1.1 FTIR Analysis
The FTIR spectra were presented in Fig. 2.3, and it shows the transformation in the
functional groups of the modified beads. A typical FTIR spectrum of pure chitosan
(CS) showed characteristic bands at 1029, 1195, 1650, 1734, 2939 and 3324 cm
−1 .
While the sharp intense peak at 1029 cm
−1 was attributed to C–O stretching vibrations
[20][1][1][2][2][2][1], the peaks around 1195 cm
−1 were assigned to C–N stretching
vibrations of amine functional group. Peaks at 1650 and 1734 cm
−1 were attributed
to C=O stretching vibrations of ketone and amide, respectively. The IR spectra peaks
showed at 2939 cm
−1 were assigned to asymmetric –CH 2 stretching [21, 25]. Finally,
the peak at 3324 cm
−1 was reported to indicate the presence of exchangeable protons