Development of Polymer Composite Beads for Dye Adsorption

ABSTRACT

Polymer composite beads of sugarcane molasses with cellulose (SM-C) were successfully synthesized using a precipitation polymerization technique. The use of sugarcane molasses as a cost-effective adsorbent for treatment of industrial effluents motivated this study. Incorporation of biomaterial (SM) resulted in enhanced adsorption properties of the polymer composite. These synthesized composite beads were utilized for effluent wastewater containing direct blue dye and direct yellow dye. Functional group detection and surface morphology were observed using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), respectively. A maximum of 50% sugarcane molasses loading was achieved, which resulted in the formation of composite beads. These beads were used to investigate the adsorption of dye from aqueous solution in a batch system. Uptake of dye from the mimicked wastewater system was followed by ultraviolet-visible (UV-Vis) spectral analysis. Detailed investigation of the initial dye concentration, amount of adsorbent, and sugarcane molasses loading in the composite was carried out. The particle size of sugarcane molasses used for synthesis also influenced the adsorption properties of the polymer composites. Sugarcane molasses greater than 50 μm proved to be effective in the formation of composite beads with an average diameter of 100 to 200 μm. SM-C polymer composite beads exhibited 84.83% and 81.71% adsorption efficiency for blue dye and yellow dye, respectively, after an exposure time of 150 min at 25°C. The adsorption isotherms were tested using Langmuir and Freundlich isotherm models. Both models provided a best fit for experimental data; however, adsorption of blue dye and yellow dye by the polymer composite could be well described by the Freundlich isotherm. The kinetics was tested with pseudo-first-order and pseudo-second-order models. The results showed that the experimental data were well fitted to the Freundlich adsorption isotherm model (R ² = 0.993 for blue dye and R ² = 0.987 for yellow dye). The rate of adsorption of blue dye and yellow dye was found to be well described by a pseudo-second-order (R ² = 0.988 for blue dye and R ² = 0.973 for yellow dye).

KEYWORDS:

• sugarcane molasses
• cellulose
• polymer composite
• adsorption
• isotherms
• kinetics

Acknowledgments

This work was supported by the Department of Applied Chemistry, DIAT (DU), and DRDO laboratories. The authors thank Dr. Prahlada, Vice Chancellor, DIAT (DU), for his encouragement in this research activity