New Biodegradable Absorbents Based on Polylactide, Poly(3-hydroxybutyrate), and Chitosan for Sorption of Iron and Chromium Ions

Film biodegradable ternary compositions of polylactide and poly(3-hydroxybutyrate) with chitosan of various compositions are prepared. The thermal properties and absorption capacity of the compositions for iron and chromium ions are studied. It is shown that the sorption activity depends both on the ratio of the components in the compositions and on the nature of metal ions and their concentration in solution. The kinetic and sorption characteristics of the process are calculated using the Langmuir model. The scanning electron microscopy study of the morphological structure of the compositions containing absorbed metal ions reveals that their surface changes significantly and a new phase appears in the form of dispersed particles, the shape and distribution of which depend on the nature of the metal.