Thermodynamic parameters for the interaction between etidronic acid and inorganic and organic mercury(II)

•For the first time, thermodynamic parameters on etidronic acid-Hg2+ and -CH3Hg+ interactions are determined.•Dependence on ionic strength and on temperature is defined by potentiometric and calorimetric tecniques.•Sequestering ability of etidronic ligand towards Hg2+ and CH3Hg+ is evaluated on the basis of speciation models.•Effect of the experimental conditions on sequestering ability is considered.