1254 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
observed that 0.5 M HCl and 0.01 M HNO3 have almost
identical desorption rates. The AH biochar desorbed using
0.2M HNO3 was further used for the second, third, and
fourth adsorption-desorption cycles in an effort to show the
re-usability of AH. However, consequent cycles showed a
drastic reduction in the adsorption capacities of AH from
72mg/g to an average capacity of 4mg/g. It can be said that
the biochar pores were blocked, and the active sites were
lost after the first cycle. This explains that the biochar struc-
ture could have also been destroyed, probably due to the
use of nitric acid, and alternative methods must be sought.
Characterization of Biochars Post Adsorption
Figure 10 shows the FTIR spectra of the biochars used. It
can be observed that the absorption peaks of these biochars
before and after adsorption are almost the same. FTIR
spectra showed no significant peak and change in the band
3400–3900, where the hydroxyl group (-OH) is observed
(Kołodyńska et al., 2018). However, at band 518cm–1,
713cm–1and 867cm–1, there was a noticeable shift in the
peak of WCC and AH after the adsorption of lanthanum,
and this can be attributed to the presence of C-H bonds
of aromatic groups (Li et al., 2019 Zhang et al., 2011).
0
20
40
60
80
100
0.2M
NaOH
0.5M
NaOH
2M
NaOH
0.2M
HCL
0.5M
HCL
0.01M
HNO
3
0.2M
HNO
3
0.5M
HNO
3
Desorbents
Figure 9. Desorption of lanthanum-loaded AH biochar using different reagents at
varying concentrations
400 900 1400 1900 2400 2900 3400 3900
Wavelength, ,cm-1
SW SW +LA WCC WCC +LA AH AH +LA
Figure 10. Fourier transform infrared spectroscopy pattern of biochars before and after the adsorption of lanthanum
Desorpti
%
observed that 0.5 M HCl and 0.01 M HNO3 have almost
identical desorption rates. The AH biochar desorbed using
0.2M HNO3 was further used for the second, third, and
fourth adsorption-desorption cycles in an effort to show the
re-usability of AH. However, consequent cycles showed a
drastic reduction in the adsorption capacities of AH from
72mg/g to an average capacity of 4mg/g. It can be said that
the biochar pores were blocked, and the active sites were
lost after the first cycle. This explains that the biochar struc-
ture could have also been destroyed, probably due to the
use of nitric acid, and alternative methods must be sought.
Characterization of Biochars Post Adsorption
Figure 10 shows the FTIR spectra of the biochars used. It
can be observed that the absorption peaks of these biochars
before and after adsorption are almost the same. FTIR
spectra showed no significant peak and change in the band
3400–3900, where the hydroxyl group (-OH) is observed
(Kołodyńska et al., 2018). However, at band 518cm–1,
713cm–1and 867cm–1, there was a noticeable shift in the
peak of WCC and AH after the adsorption of lanthanum,
and this can be attributed to the presence of C-H bonds
of aromatic groups (Li et al., 2019 Zhang et al., 2011).
0
20
40
60
80
100
0.2M
NaOH
0.5M
NaOH
2M
NaOH
0.2M
HCL
0.5M
HCL
0.01M
HNO
3
0.2M
HNO
3
0.5M
HNO
3
Desorbents
Figure 9. Desorption of lanthanum-loaded AH biochar using different reagents at
varying concentrations
400 900 1400 1900 2400 2900 3400 3900
Wavelength, ,cm-1
SW SW +LA WCC WCC +LA AH AH +LA
Figure 10. Fourier transform infrared spectroscopy pattern of biochars before and after the adsorption of lanthanum
Desorpti
%