A robust high-capacity gelatin/polyethyleneimine/poly (allylamine hydrochloride) biosorbent for uranium extraction in aqueous solution.

The development of biosorbents with high capacity, good stability and environmental friendliness has emerged as a significant objective in Uranium Extraction from Seawater (UES). Herein, we synthesized a novel biosorbent material with a complex reticular structure by simply cross-linking polyethyleneimine (PEI) and poly (allylamine hydrochloride) (PAH) onto gelatin (GEL) forming a biosorbent (GEL/PEI/PAH, GPP). The prepared biosorbent showed excellent performance with a maximum adsorption capacity of 1340.25 mg/g in solution. Furthermore, GPP exhibited impressive reusability, maintaining 92.6 % adsorption capacity and 92.8 % elution rate after 7 adsorption - desorption cycles. The main adsorption mechanism of GPP is attributed to ligand complexation reaction of amino groups on PEI or PAH and hydroxyl as well as carboxyl groups on gelatin amino acids for uranyl. Notably, GPP displayed good selective adsorption capacity for uranium, the adsorption capability was 4.4 mg/g after 15 days of immersion in real seawater. These findings show the potential applicability of biosorbent GPP for efficient uranium extraction from seawater.