Adsorption of Congo red and crystal violet dyes onto cellulose extracted from Egyptian water hyacinth

Abstract

The present investigation has highlighted the utility of floating aquatic Egyptian hyacinth, which is considered as a significant reason for environmental problems in Nile River, to offer an opportunity to effective disposal of waste and the feasibility of cellulose extraction (16%) utilizing hazard free method. Cellulose was extracted from water hyacinth fiber using mercerization, mercerization-bleaching and Soxhlet extraction method. Dearth of lignin and hemicellulose in all extracted cellulose were affirmed from FTIR spectra. The impact of extraction conditions on crystallinity, aspect ratio and thermal properties of the extracted cellulose is displayed. Mercerization method (5% NaOH) is adequate to obtain cellulose (C-5% NaOH) with high crystallinity (46.9%), high decomposition temperature and high aspect ratio. C-5% NaOH was used for expulsion of crystal violet, Congo red from aqueous solutions by adsorption method. Kinetics models were applied to estimate the rate constant and to depict the equilibrium isotherm for the crystal violet and Congo red adsorption process.