Nitrogen-doped lignin-derived biochar with enriched loading of CeO2 nanoparticles for highly efficient and rapid phosphate capture.

Development of lignin-derived carbon adsorbents with ultrahigh phosphate adsorption activity and rapid adsorption kinetics is of great importance, yet limited success has been achieved. Herein, we develop a CeO 2 functionalized N-doped lignin-derived biochar (Ce@NLC) via a cooperative modification strategy for effective and fast phosphate capture. The novel modification strategy not only contributes greatly to the loading of well-dispersed CeO 2 nanoparticles with a smaller size, but also significantly increases the relative concentration of Ce(III) species on Ce@NLC. Consequently, an enhanced capture capacity for phosphate (196.85 mg g−1) as well as extremely rapid adsorption kinetics were achieved in a wide operating pH range (2–10). Interestingly, Ce@NLC exhibited a strong phosphate adsorption activity at even low-concentration phosphorus-containing water. The removal efficiency and final P concentration reached 99.87% and 2.59 μg P L−1 within 1 min at the phosphate concentration of 2 mg P L−1. Experiments and characterization indicated that Ce(III) species plays a predominant role for the phosphate capture, and ligand exchange, together with electrostatic attraction, are the main adsorption mechanism. This work develops not only an efficient carbon-based adsorbent for phosphate capture, but also promotes the high-value application of industrial lignin. Nitrogen-doped lignin-derived biochar with enriched loading of CeO 2 nanoparticles for highly efficient and rapid phosphate capture. [Display omitted] • Ce@NLC with smaller and Ce(III)-enriched CeO 2 nanoparticles is developed. • The maximum phosphate capture capacity of Ce@NLC reaches 196.85 mg g−1. • Ce@NLC exhibits a rapid phosphate capture in wide operating pH range (2–10). • Ce@NLC possesses strong adsorption activity at even a low phosphate concentration. [ABSTRACT FROM AUTHOR]