CO2_2016 - page 51

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Chimica Oggi - Chemistry Today
- vol. 34(2) March/April 2016
CONCLUSION
Our results showed the ability of CMK-3 to adsorb
rapidly the highly toxic Pb (II), Ni (II) and Cd
(II) without any modification of its surface. The
adsorption capacity for Pb (II), Ni (II) and Cd
(II) followed the order Pb (II) > Ni (II) > Cd (II) ,
which was inversely proportional to the hydrated
ionic radius of the metals. The lead removal on
CMK-3 was pH dependent, it increased with the
increase of pH showing a maximum at pH 6.3.The
adsorption of Pb (II) decreased slightly in binary
system (Pb (II) + Cd (II), Pb(II) + Ni(II)). Interestingly,
in the ternary system ( Pb (II) + Cd (II)
+ Ni (II)) there
was a substantial improvement in the removal
of Pb (II), showing that CMK-3 is a potential
candidate as adsorbent for the lead removal
fromwastewater.
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Figure 3.
Adsorption isotherms of metal ions,
Pb (II), Ni(II) and Cd (II), in linear forms of
Langmuir model.
Table 3.
Freundlich parameters and Langmuir parameters of Pb, Ni and Cd ions
adsorbed on CMK-3 for contact time of 60 min and 5 mg of the adsorbent.
Table 4
.
Adsorption
capacity versus
hydrated radius of
metal.
Figure 5.
Adsorption
of lead from binary
and ternary metal
solutions.
Figure 4.
Adsorption isotherms of metal
ions,Pb (II), Ni(II) and Cd (II), in linear
forms of Freundlich model.
Table 5
.
Adsorption capacity of lead on different adsorbents.
(49)
(50)
(51)
(52)
(53)
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1...,41,42,43,44,45,46,47,48,49,50 52,53,54,55,56,57,58,59,60,61,...68
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