Lanthanum-loaded polyacrylonitrile fiber as an efficient phosphate adsorbent

Abstract

Lanthanum (La) emerged as a promising candidate for phosphate removal due to its inherent high affinity towards phosphates. However, addressing issues related to lanthanum aggregation often required loading lanthanum onto suitable carriers. While composite La with nanomaterials showed effective enhancement in adsorption performance, their practical environmental applicability remained limited. In this study, lanthanum was immobilized onto polyacrylonitrile (PAN) fibers modified with triethylenetetramine. The resulting lanthanum-loaded polyacrylonitrile (La@PAN) fibers exhibited a remarkable maximum phosphate adsorption capacity of 83.33 mg P g−1, significantly higher than most previously reported fiber-based adsorbents. Moreover, these fibers achieved adsorption equilibrium within 20 min and demonstrated excellent adsorption capabilities within a broad pH range of 3–6. Even after five regeneration cycles using NaCl solution, the adsorption capacity retained 82.51 % of its initial value, indicating excellent environmental applicability. Importantly, these fiber adsorbents possessed unique flexibility and weavability, allowing them to be tailored into different shapes according to dynamic application demands, thus offering customized solutions for specific environmental challenges.