Fig. 5: The adsorption model of Cr(VI) removal by EW-BC.

a The quasi-first-order kinetic model and quasi-second-order kinetic model of Cr(VI) removal by EW-BC in initial Cr(VI) concentration of 100, 300, 500, and 700 mg L−1 respectively. b The Langmuir and Freundlich isotherm parameters for Cr(VI) removal by EW-BC. The Qe (mg g−1) were the removal capacity at removal equilibrium.