Isotherm parameters.

Isotherms parameters were determined from Langmuir and Freundlich models for Cd2+ adsorption on the EPS of Rhizobium alamii in a MOPS buffer or calcium nitrate (10−2 M) at pH 6.5. The reaction was maintained at 25°C under stirring, pH 6.5±0.2 for 24 h and 48 h to ensure that the equilibrium was reached.The metal uptake, X (mol.kg−1) is determined using: X = V. (C0−Ce). M−1 where C0 and Ce are the concentrations of initial and equilibrium cadmium in the solution (mol.L−1), respectively; V is the solution volume (L); M is the mass of sorbent (kg). The error bars represent the confidence intervals (95%) of triplicates.