Biodegradable chitosan hydrogels crosslinked with Fe(III) doped montmorillonite (MMT) nanoclay flakes were developed for phosphate absorption from aqueous solutions. Around 10 mg P/g gel was absorbed within 1 hour during the batch experiment. The fast absorption kinetics of phosphate ions by the nanocomposites under varying pH was attributed to the electrostatic interaction between the cationic chitosan chain and phosphate anions and ligand exchange with iron hydrolysates. Reversible physical crosslinking between two-dimensional MMT and chitosan chains contributes to the excellent expandability and degradability of the chitosan nanocomposite scaffold. The chitosan nanocomposites saturated with phosphate can be used in the soil as controlled-release fertilizer. During the swelling of the scaffold, phosphate nutrient ions were released into the medium in a controlled manner benefitting the nutrient use efficiency by plants. Highly degradable and biocompatible chitosan-MMT-Fe nanocomposites can be applied in the field without compromising the long-term fertility of the soil.

Engineered biopolymer nanocomposite for phosphate reclamation and controlled release

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.