Amino‐Modified Cellulose Gel Adsorbent for Highly Efficient and Selective Removal of Anionic Dyes

Abstract The adsorbents with low cost, high adsorption capacity, and fast adsorption efficiency hold significant promise for practical applications. In this study, an amino‐modified cellulose (AMCC) gel was synthesized via a straightforward one‐step method using microcrystalline cellulose. The resulting gel featured a high density of surface amino groups, thereby enhancing the electrostatic interaction between protonated amine groups and negatively charged sulfonic acid groups of anionic dyes. And the mixed adsorption experiments show that AMCC gel had excellent adsorption selectivity for anionic dyes. Compared to MCC, the adsorption capacities of AMCC gel increased by 2.8 times for methyl orange (MO) and 7.6 times for tartrazine (TTZ). The adsorption behavior closely followed Langmuir isotherm ( R 2 = 0.999) and pseudo‐second‐order kinetic ( R 2 = 0.999) models. And the maximum adsorption capacities for MO and TTZ were 763.36 and 456.62 mg∙g −1 , respectively. Moreover, the adsorption process was completed within approximately 60 min for MO and 10 min for TTZ. The results indicate that AMCC gel offers excellent performance in removing anionic dyes, with the added advantages of simple preparation and low cost, making it a promising candidate for practical wastewater treatment.