Eco-Friendly Synthesis of Carbonized Cellulose Aerogels from Olive Stone Waste: Structure and Properties

Abstract

In this study, carbonized cellulose-based aerogels were synthesized from olive stone waste via low-temperature hydrothermal carbonization combined with sol–gel polymerization. The extracted cellulose was partially carbonized to obtain functionalized precursor structures containing oxygen-rich active groups suitable for aerogel formation. Carbonized cellulose was blended with chitosan and crosslinked using epichlorohydrin to produce stable three-dimensional porous aerogels through solvent exchange and freeze-drying processes. The physicochemical properties of the synthesized aerogels were investigated using FTIR, XRD, SEM, and water adsorption analyses. FTIR spectra confirmed structural modifications after carbonization and crosslinking, while XRD results revealed a predominantly amorphous structure with reduced crystallinity. SEM images demonstrated a porous morphology with irregular interconnected voids. The carbonized cellulose aerogel exhibited moderate adsorption performance toward olive wastewater, with an adsorption capacity of 100 mg g⁻¹. The results suggest that olive stone-derived carbonized cellulose aerogels could serve as low-cost, eco-friendly, and sustainable adsorbent materials for wastewater treatment and agricultural waste valorization.

Keywords

• Olive waste
• aerogel
• carbonized cellulose
• hydrothermal carbonization
• waste recycling

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