Three-dimensional porous aerogel-bead absorbent with high dispersibility of lanthanum active sites to boost phosphorus scavenging

Abstract

Excessive phosphorus (P) emission from sewage to water bodies is still a global challenge that threatens environmental safety. Here, La-based aerogel beads (LCM) with a lanthanum (La) complex core were prepared via crosslinking to serve as a novel P scavenger. The chelation of the central La active sites with the alginate ligand to form complexes made the LCM beads stable in water. La active sites, as the core of LCM, existed high dispersibility in the surface and interior of the aerogel beads, which made it exhibit high utilization of La active sites and a high P/La molar ratio (P/La: 2.80), which was 2 ∼ 10 times that of other La-loaded adsorbents. Due to the high dispersion of La active sites, LCM achieved a high adsorption capacity of 624.57 mg P/g La. Besides, the LCM beads also achieved a high mass transfer efficiency due to the unique three-dimensional porous structures of the beads. Apart from the excellent P capture performance of the LCM aerogel beads, the physicochemical properties of LCM facilitated their separation from the treatment water and subsequent regeneration, making this a promising adsorbent for P uptake from wastewater.