Delignification, Cellulose Crystallinity Change and Surface Modification of Coir Pith Induced by Oxidative Delignification Treatment

Abstract

Lignocellulosic agroindustrial residue, the coir pi th, poses severe pollution threats to land and water environment due to polyph enol leaching and its resistance for natural degradation. Overcoming of structural hindr ances offered by coir pith has to be attained for preparing the substrate suitable for b ioenergy production, and oxidative delignification has been found to be the promising option to achieve this goal. Mild hydrogen peroxide treatment was performed on coir pith to loosen the lignocellulosic binding. Treatment optimization was done based on substrate concentration and duration. Klason lignin of coir pith was estimated by chemica l method. Investigations on structural modifications were carried out by FTIR, XRD and SEM analysis. Delignification efficiency of 53% was estimated and lignin loss and structural changes were analyzed by FTIR. XRD analysis led to the inference of cellulos e crystallinity index reduction. SEM analysis indicated smoothening of surface and chang e of porous surface into pleet like structure. Thus to a greater extent optimised oxida tive delignification process attained the pretreatment goals of delignification, cellulose cr ystallinity index reduction and surface modification.