Converting large-scale waste paper fibers into lanthanum-modified cellulose carbon aerogel adsorbents for efficient phosphorus removal

This study presents the synthesis of a novel lanthanum-modified cellulose-based carbon aerogel (La-CCA) from waste printing paper, aimed at addressing the issue of phosphate pollution in aquatic environments. The objective was to develop an effective and sustainable adsorbent to mitigate eutrophication caused by excess phosphates in water bodies. La-CCA exhibited a remarkable phosphate adsorption capacity, peaking at 44.32 mg/g under optimal conditions, demonstrating its efficiency as an adsorbent. The novelty of this work lies in the use of waste paper as a raw material, coupled with lanthanum modification, which enhanced adsorption performance through multiple mechanisms, including electrostatic interactions, ligand exchange, and inner-sphere complexation. The study also discussed the retention of the microfibrous structure of cellulose, contributing to the material’s stability and functionality. Comprehensive analyses including zeta potential, FTIR, and XPS elucidate the underlying adsorption mechanisms. La-CCA was demonstrated to be easily separable from solutions with minimal lanthanum leaching, particularly under conditions above pH 3.0, underscoring its potential for practical applications in phosphate removal from nutrient-enriched waters.