4 Characterization of Biosorbents
The physical nature of the biosorbents such as size, shape, surface area, pore size and
chemical nature such as functional groups can be characterized by different methods.
Some of the methods are listed below.
4.1 Microscopy
Physical structure and surface morphology of the adsorbent can be studied using
scanning electron microscopy (SEM). Pores in the surface of the biosorbent can be
visualized by the SEM. Also the metal binding to the surface of the adsorbent can be
visualized by the SEM images taken before and after the adsorption [21].
4.2 Spectroscopy
Fourier transform infrared (FTIR) spectroscopy and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy are the methods to identify the
functional groups and the bonding between the atoms in a compound. By analysing a
Table 1 (continued)
Biosorbent
Adsorbate
Pre-treatments
Reference
Bengal Gram
Seed husk
Congo red
Size reduction (grinding and sieving
between 53 and 75 μm mesh)
Somasekhara
Reddy et al.
[9]
Wood chip
Levofloxacin
Pyrolysis at 300 and 600
C
Yi et al. [17]
Fish scales
Orange 16
Carbonization in the presence of N 2 at
600
C, washing by 1 M HCl, drying t
105
C and ground to a mesh of 250–
500 μm
Marrakchi
et al. [14]
Lanthanum
Size reduction to 425–600 μm size
Das et al. [36]
Animal bone
meal
Rhodamine –
B
Size reduction (grinding to powder)
El Haddad
et al. [15]
Sorghum straw,
oats straw, agave
bagasse
Chromium
(III)
Size reduction to 1 mm diameter, acid
treatment by 0.01 N hydrochloric acid
and drying at 50
C for 24 h
Bernardo
et al. [6]
Potato plant
leaves and stem
Methylene
blue and malachite green
Boiling to separate fibres, size reduced by
grinding to 100–150 μm
Gupta et al.
[37]
Haloxylon
recurvum
Methylene
blue
Drying and size reduction by grinding
Hassan et al.
[12]
Neem saw dust
Lanthanum
Size reduction to 425–600 μm size
Das et al. [36]
248
K. J. Samuel P N et al.
The physical nature of the biosorbents such as size, shape, surface area, pore size and
chemical nature such as functional groups can be characterized by different methods.
Some of the methods are listed below.
4.1 Microscopy
Physical structure and surface morphology of the adsorbent can be studied using
scanning electron microscopy (SEM). Pores in the surface of the biosorbent can be
visualized by the SEM. Also the metal binding to the surface of the adsorbent can be
visualized by the SEM images taken before and after the adsorption [21].
4.2 Spectroscopy
Fourier transform infrared (FTIR) spectroscopy and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy are the methods to identify the
functional groups and the bonding between the atoms in a compound. By analysing a
Table 1 (continued)
Biosorbent
Adsorbate
Pre-treatments
Reference
Bengal Gram
Seed husk
Congo red
Size reduction (grinding and sieving
between 53 and 75 μm mesh)
Somasekhara
Reddy et al.
[9]
Wood chip
Levofloxacin
Pyrolysis at 300 and 600
C
Yi et al. [17]
Fish scales
Orange 16
Carbonization in the presence of N 2 at
600
C, washing by 1 M HCl, drying t
105
C and ground to a mesh of 250–
500 μm
Marrakchi
et al. [14]
Lanthanum
Size reduction to 425–600 μm size
Das et al. [36]
Animal bone
meal
Rhodamine –
B
Size reduction (grinding to powder)
El Haddad
et al. [15]
Sorghum straw,
oats straw, agave
bagasse
Chromium
(III)
Size reduction to 1 mm diameter, acid
treatment by 0.01 N hydrochloric acid
and drying at 50
C for 24 h
Bernardo
et al. [6]
Potato plant
leaves and stem
Methylene
blue and malachite green
Boiling to separate fibres, size reduced by
grinding to 100–150 μm
Gupta et al.
[37]
Haloxylon
recurvum
Methylene
blue
Drying and size reduction by grinding
Hassan et al.
[12]
Neem saw dust
Lanthanum
Size reduction to 425–600 μm size
Das et al. [36]
248
K. J. Samuel P N et al.