Table 6: Gibbs free energy (KJ/mol), Enthalpy change (KJ/mol) and Entropy Change (KJ/molK) for the removal of Cu and Fe ions on CHS and COMP.

 

 

Heavy metal ions

 

Adsorbent

Temperature (K)

Cu

Fe

CHS

303

-1.401

-1.731

 

318

-1.607

-1.825

 

333

-1.695

-1.914

 

348

-1.868

-2.005

 

363

-1.804

-2.091

COMP

303

-1.484

-1.619

 

318

-1.576

-1.718

 

333

-1.787

-1.830

 

348

-1.898

-1.991

 

363

-1.932

-2.057

CHS

ΔH

0.781

0.111

 

ΔS

0.007

0.006

COMP

ΔH

1006.376

853.350

 

ΔS

8.233

8.120