Competitive Adsorption of Metals onto Magnetic Graphene Oxide: Comparison with Other Carbonaceous Adsorbents
Table 3
Isotherm model parameters of the metal adsorption on PAC and MWCNT at pH 7.0.
Adsorbents
Systems
Metals
Langmuir
Freundlich
PAC
Single metal
Cu(II)
34.72 ± 1.47e
0.94 ± 0.13e
0.993
15.54 ± 1.54e
0.40 ± 0.07e
0.931
Pb(II)
35.15 ± 1.15
1.30 ± 0.14
0.995
17.04 ± 1.60
0.39 ± 0.07
0.925
Cd(II)
11.23 ± 0.38
0.11 ± 0.01
0.999
1.40 ± 0.11
0.60 ± 0.03
0.994
Multimetal
Cu(II)
32.79 ± 0.76
0.73 ± 0.05
0.998
12.93 ± 0.99
0.44 ± 0.05
0.970
Pb(II)
35.08 ± 0.38
0.617 ± 0.02
0.999
12.69 ± 0.98
0.46 ± 0.05
0.972
Cd(II)
6.84 ± 0.20
0.10 ± 0.01
0.999
0.85 ± 0.09
0.595 ± 0.04
0.988
MWCNT
Single metal
Cu(II)
41.42 ± 0.58
0.72 ± 0.03
0.999
17.49 ± 0.98
0.41 ± 0.04
0.988
Pb(II)
59.08 ± 0.37
1.22 ± 0.02
0.999
30.95 ± 0.96
0.57 ± 0.05
0.983
Cd(II)
23.07 ± 0.97
0.13 ± 0.01
0.998
3.34 ± 0.45
0.60 ± 0.06
0.976
Multimetal
Cu(II)
36.53 ± 2.63
1.13 ± 0.33
0.985
19.11 ± 0.54
0.32 ± 0.02
0.994
Pb(II)
48.21 ± 2.00
0.36 ± 0.03
0.998
12.53 ± 0.57
0.58 ± 0.03
0.993
Cd(II)
17.86 ± 0.56
0.11 ± 0.01
0.999
2.26 ± 0.27
0.62 ± 0.05
0.983
Maximum adsorption capacity estimated by Langmuir isotherm model (mg g−1).
bAdsorption affinity estimated by Langmuir isotherm model (L mg−1).
cFreundlich model capacity ((mg/g) ).
dFreundlich model site heterogeneity factor (dimensionless).
eStandard errors.