274
of Cr(VI) ions from the time of adsorption is shown in Figs. 9.9 and 9.10. Analyzing
the results, it can be concluded that the tested systems reach the equilibrium after
45–60 min of adsorption for initial concentrations of 0.3 and 0.4 mg/l, while it took
120–150 min to reach the steady state for the concentrations of 0.5 and 0.6 mg/l.
9.3.8 Equilibrium of the System Cr(VI) Ions-Clayey Diatomite
Obtaining experimental data for the system Cr(VI) ions-clayey diatomite is performed using four equilibrium isotherms as follows: Langmuir, Freundlich,
Langmuir-Freundlich, and Redlich-Peterson. Selecting the proper isotherm is
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0
50
100
150
200
γt [mg/l]
t [min]
γo = 0.6 mg/l
γo = 0.5 mg/l
γo = 0.4 mg/l
γo = 0.3 mg/l
Fig. 9.9 Dependence of adsorbate concentration from time of adsorption for the system Cr(VI)
ions – clayey diatomite
0
0.05
0.1
0.15
0.2
0.25
0
5 0
1 00
150
2 00
q
t [mg/g]
t [min]
γo = 0.3 mg/l
γo = 0.4 mg/l
γo = 0.5 mg/l
γo = 0.6 mg/l
Fig. 9.10 Dependence of adsorbed amount of Cr(VI) from time of adsorption for the system
Cr(VI) ions – clayey diatomite
H. Memedi et al.