<p>In this study, cationic cellulose fiber adsorbent was prepared through a two-step reaction from commercial cellulose, using an oxidizing agent (sodium periodate) and Girard’s reagent as a cationizing agent. The performance of cationic cellulose for adsorption and separation dye was examined by anionic organic dyes. The prepared adsorbent was able to remove the dyes with the maximum adsorption capacity for Eriochrome Cyanine R, methyl orange, and Zincon being 65.33, 63.33, and 65.32 mg/g, respectively. To explore the adsorption mechanism of the sorbent, the influence of pH, initial dye concentration, contact time, temperature, and adsorbent dose on the activity of adsorption towards anionic dyes were studied, as was the equilibrium dose of cationic cellulose (0.075 g) for removal of 100 mg/L from the studied dyes. The equilibrium data adsorption of cationic cellulose was discovered to be suitable well to the Langmuir isotherm model with correlation coefficient (R² &gt; 0.982) and pseudo-second-order model. The process of dyes adsorption on cellulose functionalized was spontaneous exothermic (∆G and ∆S &lt; 0), monolayer chemisorption. Utilizing the molecular operating environment software, molecular docking simulations were performed for the cellulose functionalized compound. The results from the docking simulation demonstrated that the modified cellulose compound exhibited increased potency and displayed a higher binding affinity towards the Avr2 effector protein obtained from the fungal plant pathogen Fusarium oxysporum (code 5OD4). The modified cellulose was successfully utilized for the anionic dyes removal from real wastewater samples and synthetic effluents, with a recovery % of more than 87%. The distinctive complementary features of regenerated cellulose will facilitate its removal of a variety of organic dyes from wastewater of industries.</p>