Use of Ethylenediaminetetraacetic Acid as a Scavenger for Chromium from “Wet Blue” Leather Waste: Thermodynamic and Kinetics Parameters

Table 1

Variation of the Gibbs free energy for complexation reaction in kcal·mol⁻¹.

Complex	Charge on the Cr atom
Cr(EDTA)	+6	−322.75	0.00
Cr(EDTA)	+3	−316.99	5.76
Cr(NTA)(H2O)2	+6	−311.02	11.73
Cr(NTA)(H2O)2	+3	−305.93	16.82
Cr(collagen)	+6	−289.70	33.05
Cr(collagen)	+3	−286.66	36.09