TEMPERATURE CONSTRAINTS AND THERMODYNAMIC PARAMETERS ON THE REMOVAL OF Hg (II), Pb(II), AND Cd(II) IONS FROM AQUEOUS SOLUTION USING MODIFIED AND UNMODIFIED SHELLS OF THAIS CORONATA AND CRASSTROTREA GASAR

Temperature constraints and thermodynamic parameters on the removal of Hg (II). Pb(II), and Cd(II) ions from aqueous solution using modified and unmodified shells of Thais coronata (gastropoda) and Crasstrotrea gasar (bivalve) were studied. The results show that the maximum removal (99.98 %, 99.99 % and 99.78 %) on USASA for Hg (II), Pb(II) and Cd(II) ions respectively was achieved at temperature 303 K. The various thermodynamic parameters, such as ΔGo, ΔHo , and ΔSo and Ea were evaluated. The values obtained for ΔGo, ΔHo , and Ea were all negative while the values obtained for ΔSo were positive. These indicate that the sorption process is exothermic and spontaneous in nature. Shells of Thais coronata and Crasstrotrea gasar, cheaper, environment friendly and abundantly available agricultural materials were proven to be an excellent adsorbent for the removal of Hg (II). Pb(II), and Cd(II) ions from aqueous solutions at maximum temperature of 303 K.