<p>Recent environmental issues, such as climate change, air, water, soil pollution, biodiversity loss, and deforestation, take a heavy toll on the natural ecology of many living being including humans. To ease the situation, scientists and environmentalists are working on innovative approaches to purify and clean our surroundings. This study aims to present a sustainable adsorbent material—cross-linked chitosan bentonite composite to remove the harmful malachite green dye from wastewater system. Dyes are an integral part of many industries and find their way to the natural water bodies through drainage systems carrying effluents. A blend of two environment-friendly and efficient materials, namely chitosan and bentonite, are used for removal of dye molecules. The study includes characterization studies of the adsorbent using techniques of FT-IR, SEM-EDAX, XRD, and TG–DTA analysis along with optimization of operational parameters, such as pH, dose, concentration, and time, through batch adsorption experiments. A mathematical model, response surface methodology has been implemented to the data obtained in order to collect information regarding optimization of the process. Apart from this, the kinetic and isothermal analysis was also performed to get insights of the adsorption phenomena. The observed data on adsorption isotherm correlated to Langmuir isotherm model with adsorption capacity of 333.33&#xa0;mg L⁻¹ and data on kinetics suggested pseudo-second-order mechanics for uptake of dye with R² value greater than 0.999 showing linear relationship. Furthermore, the fixed-bed or column adsorption method was also studied to evaluate column parameters.</p> Graphic abstract <p></p>