Isotherm and Thermodynamic Studies on Pb(II), Ni (II), Cd (II) ions sorption from aqueous solution using calopogoniumniuconoides (CALOPO):-Uko, Anthonia E.

ABSTRACT

The removal of Cdfllk Pb(Il) and Ni(ll) from solution using calopo (ccilo/xigonii/niiniiconoiik’s) pod as adsorbent was studied. The effect of dosage, and metal ion concentration on the adsorption were examined. The residual Cd(Il), Pb(Il) and Ni(II) in solution was determined using atomic adsorption spectrophotometer. The equilibrium adsorption data were described by Temkin Langmuir Dubinin-Raduskevich and Freundlich isotherm models. The coefficients of correlation ofthe four models were high with Langmuir isotherm being the most fit. The ma.ximium adsorption capacity of Ni(II), Pb(II), and Cd(Il) are 43.103mg'g,42.373mg/g and 32.33mg/g respectively .The adsorption process is endothermic and thermodynamically feasible and increase in entropy since change in enthalpy(AH°). Gibb's free energy(AG°), and change in entropy(AS°) are positive, negative and positive respectively. Therefore, CalopogoniuniMuconoidesis a promising adsorbent for adsorption ol'Ni(ll). Pb(ll) and Cd(II) ions.