Analysis of adsorption isotherms of Cu(II), Ni(II), Pb(II) and Zn(II) by N-(3,4-dihydroxybenzyl) chitosan using nonlinear regression method.

Adsorption of Cu(II), Ni(II)? Pb(ID and Zn(II) ions from aqueous solutions by N-(3,4-dihydroxybenzyl) chitosan have been carried out, The Langmuir (L), Freundlich (F), Langmuir - Freundlich (LF), Redlich-Peterson (RP) and Toth (T) adsorption isotherms models have been applied to fit the experimental data, Nonlinear regression computational program "Enzefitte", which is a library of the more commonly used adsorption isotherm equations for obtaining tabular outuput suitable for plotting theoretical of fitted isotherms, has been used to estimate the adsorption parameters, These parameters were used to calculate the amount adsorbed q(calc.), a function of concentration (C).