Sustainable valorization of agricultural residues into high-value biomaterials offers a green route to wastewater remediation. This study demonstrates the enzymatic extraction of nanocellulose (EN-NC) from sugarcane trash (SCT) using a synergistic combination of recombinant β-1,4-endoglucanase ( At GH9C-CBM3A-CBM3B) and cellobiohydrolase ( At CBH5A) from Acetivibrio thermocellus , offering a green alternative to conventional chemical methods. The enzymatic process, characterized by restricted hydrolysis, yielded nanocellulose with uniform, ultra-thin fibrils (≤ 20 nm) and crystallinity index (46.8%), which was incorporated into a carboxymethyl cellulose hydrogel (EN-NC–CMC-Na). This hydrogel exhibited a significantly enhanced surface area (4.8 m 2 /g) and a well-defined point of zero charge (pH pzc 6.6). Optimization via Response Surface Methodology revealed maximum removal efficiencies of 88.5% for Congo Red and 94.7% for Methylene Blue, by EN-NC–CMC-Na and the adsorption kinetics followed a pseudo-second-order model. Isotherm studies indicated multilayer adsorption on a heterogeneous surface, with maximum capacities of 35.6 mg/g and 40.7 mg/g for CR and MB, respectively. The hydrogel also demonstrated excellent regenerative potential using eco-friendly eluents. These findings establish enzymatic nanocellulose extraction from SCT as a green and scalable alternative to chemical nanofibrillation, while the resulting hydrogel provides a reusable, high-performance adsorbent for dye-laden effluents.
Mandal et al. (Thu,) studied this question.