Composite Beads of Chitosan/Bentonite as A Matrix For Phosphate Fertilizer Controlled-Release

Abstract

Composite beads of chitosan-based have prepared as matrix to study phosphate-release properties. The composite beads contain of chitosan and bentonite. In here, Chitosan with various molecular weight (MW) (low, medium and high) were used as variable to study their physical properties. Meanwhile, swelling degree and phosphate release of composite beads were investigated in various of pH. As the result, composite beads with high MW of chitosan show that qualitatively have higher mechanical stability than medium and low MW chitosan. Swelling degree of composite beads increase with increase MW of chitosan. Compared to native chitosan, composite beads showing higher swelling degree. Phosphate-release measurement shows that controlled-release behavior was affected by pH of solution media with pH in order pH 3 > pH 7 > pH 10.