Multifunctional polyamidoxime-co-polyethyleneimine tailored cellulose derived from sustainable biomass for effective removal of acidic dye pollutants from wastewater

Multifunctional polymers derived from waste biomass are under intense global investigation for wastewater remediation owing to their environmental advantages. Therefore, this study reports the synthesis of a novel polyamidoxime-co-polyethyleneimine multifunctional cellulose, which was used as an adsorbent for the removal of acidic dye pollutants. Morphological, structural, and surface studies were performed using several techniques. BET analysis reveals the mesoporous nature of multifunctional cellulose, and the point of zero charge (Pzc) of the adsorbent was around 7.8. The adsorbent shows better removal efficiency for acidic dyes at low pH due to electrostatic attraction and enhanced adsorption kinetics. The order for dye pollutants from fastest to slowest in reaching equilibrium is as follows: AMR ˃ TA ˃ EBT. From the isotherm studies, the Langmuir isotherm model fits well, and multifunctional cellulose displays maximum adsorption capacities of 108.96 mg g⁻¹, 93.78 mg g⁻¹, and 125.96 mg g⁻¹ for tartrazine, amaranth, and Eriochrome black T acidic dyes, respectively. From the reusability studies, it is observed that the multifunctional cellulose adsorbent attains adequate adsorption values after five adsorption-desorption cycles, with cumulative adsorption capacities of 363.25 mg g⁻¹, 345.34 mg g⁻¹, and 421.22 mg g⁻¹ for TA, AMR, and EBT dye pollutants, respectively.