Removal of Co(II), Cu(II) and Pb(II) ions by polymer based 2-hydroxyethyl methacrylate: thermodynamics and desorption studies

Removal thermodynamics and desorption studies of some heavy metal ions such as co(ii), cu(ii) and pb(ii) bypolymeric surfaces such as poly 2-hydroxyethyl methacrylate (phema) and copolymer 2-hydroxyethyl methacrylatewith monomer methyl methacrylate p(mma-hema) as adsorbent surfaces from aqueous single solution wereinvestigated with respect to the changes in ph of solution, adsorbent composition, contact time and temperaturein the individual aqueous solution. the linear correlation coefficients of langmuir and freundlich isotherms wereobtained and the results revealed that the langmuir isotherm fitted the experiment results better than freundlichisotherm. using the langmuir model equation, the monolayer removal capacity of phema surface was found to be0.7388, 0.8396 and 3.0367 mg/g for co(ii), cu(??) and pb(ii) ions and removal capacity of p(mma-hema) was foundto be 28.8442, 31.1526 and 31.4465 mg/g for co(ii), cu(??) and pb(ii) ions, respectively. changes in the standardgibbs free energy (?g0), standard enthalpy (?h0) and standard entropy (?s0) showed that the removals ofmentioned ions onto phema and p(mma-hema) are spontaneous and exothermic at 293–323 k. the maximumdesorption efficiency was 75.26% for pb(ii) using 0.100 m hno3, 70.10% for cu(ii) using 0.100 m hcl, 59.20% for0.100 m hcl 63.67% co(ii).