Removal of Textile Dyes from Aqueous Solutions and Wastewaters using Biobased Interpenetrating Networks of Alginate, Collagen, and Polyurethane

Abstract

The aim of this work was to study the adsorption properties of interpenetrating polymeric networks (IPNs) based on alginate, collagen, and two different polyurethanes (ACP(HDI), ACP(IPDI)) for the removal of textile dyes from aqueous solutions and wastewaters. The interaction of ACP(HDI) and ACP(IPDI) with methylene blue (BB9), malachite green (BG4), indigo carmine (AB74), and Congo red (DR28) was studied by adsorption kinetics and adsorption isotherms. Concentration profiles revealed a fast removal of dyes from aqueous solutions reaching the equilibrium after 4 h of contact. ACP(IPDI) removed up to 87 ± 0.5% of BG4 and the removal efficiency for the other dyes was lower. Experimental data fit the pseudo-second-order model showing that the removal process is controlled by diffusion. Adsorption isotherms were described by the Freundlich’s model observing concave up isotherms. Results showed that IPNs obtained from the polyurethane containing P(IPDI) cyclic moieties are better for dye removal than those obtained from the P(HDI) acyclic polyurethane.