The bimetallic metal organic framework (MOF), (Fe-Co)/BDC was synthesized via solvo-thermal method. PXRD, SEM/EDX, FTIR, Raman, XPS and BET were applied to characterize the as synthesized, (Fe-Co)/BDC. Characterization results reveals that (Fe-Co)/BDC MOF is flexible crystalline nano-porous material with significant anion exchange capability due to chloride resident-in-matrix anion. The evaluation of its adsorptive ion exchange against Cr-oxyanions was performed. Kinetic study applying pseudo first order (PFO), pseudo second order (PSO), diffusion-binding (DB), and Weber-Morris (WM) models suggests pseudo first order as suitable to represent the adsorption kinetics with diffusion is an effective step. Generally, Kinetic study revealed the speedy nature of of Cr-oxyanion adsorption with significant reversibility and simple regeneration by NaCl solution. Freundlich and Langmuir models were applied for isotherm study under isoelectric condition, for adsorption equilibrium assessment. The study showed that (Fe-Co)/BDC has a notable capacity towards of about 588 mg.g–1 for Cr-oxyanions contamination. Breathing effect is suggested to have a function to adsorption mechanism especially for the internal adsorption sites.