Cr(VI) adsorption on an improved synthesised cross-linked chitosan resin

► Chitosan resin was synthesised by an improved drop-sphere-forming method. ► The resin has a high adsorption capacity to Cr(VI) after crosslinking. ► The removal mechanism may include both physical adsorption and ion exchange. ► The experimental data was fitted to pseudo second-order and Langmuir isotherm.