Preliminary Investigation into the Use of Amino-Acid-Derived Ionic Liquids for Extracting Cellulose from Waste Biomass to Prepare Cellulose Aerogel Adsorbents

To investigate the feasibility of cellulose extraction from lignocellulosic waste biomass using ionic liquids-a sustainable and efficient approach-for preparing cellulose aerogel adsorbents, we employed a fully green amino acid-derived ionic liquid, cysteine nitrate ([Cys][NO₃]), for cellulose separation from diverse biomass sources. The extracted cellulose, with a purity range of 83.8-93.9%, was processed into cellulose aerogels (CAs) via a conventional aerogel preparation protocol. The resulting CA exhibited promising adsorption capacities, including 0.2-11.6 mg/g for Na⁺, 4.4-19.9 mg/g for Ca²⁺, 4.15-35.6 mg/g for Mg²⁺, and 1.85-13.3 mg/g for Cd²⁺, as well as 9.7-17.7 g/g for engine oil. These results demonstrate the presence of effective mass transfer channels in the CA, proving that the cellulose's fibrillation capacity was preserved in the pre-treatment. This study illuminates the potential of this green, straightforward method for preparing aerogels from cellulose derived from waste biomass, with promising applications in wastewater treatment and material recovery.