International Journal of Advanced Engineering Research and Science (IJAERS) https://dx.doi.org/10.22161/ijaers.4.5.9
[Vol-4, Issue-5, May- 2017] ISSN: 2349-6495(P) | 2456-1908(O)
Equilibrium Isotherm, Kinetic and Thermodynamic Studies of the Adsorption of Erythrosine Dye onto Activated Carbon from Coconut Fibre Ikhazuangbe P.M.O., Kamen F.L., Opebiyi S.O., Nwakaudu M.S., Onyelucheya O.E. Department of Chemical engineering, Federal University of Technology, Owerri, Nigeria Abstract – Equilibrium isotherm, kinetic and thermodynamic studies of the adsorption of erythrosine dye onto activation carbon from coconut fire was carried out. The coconut fibre obtain from Elele, Rivers State Nigeria, was washed, dried, carbonized at 400oC, crushed, sieved and activated at 800oC, before it was washed and dried at 110oC. Variable influencing factors, such as contact time, temperature and initial concentration were studied through single-factor experiment, while other factors are kept constant (at 30min, 30oC and 50mg/L) in each adsorption experiment. The Freundlich isotherm fits adsorption compare to others used, the adsorption kinetic followed pseudo-second order reaction, while the thermodynamic parameters, (∆H) = 28.73KJ/mol, (∆đ??ş) = 94.45J/mol.K and (∆S) = -0.10, -0.27, -0.82, -1.05, -1.77, -2.49KJ/mol. From the results obtained, activated carbon from coconut fibre, will be an excellent low-cost adsorbent for the removal of Erythrosine from industrial waste water. Keywords— Adsorption, Coconut fibre, Erythrosine, Kinetic, Thermodynamic. I. INTRODUCTION Erythrosine or Acid Red is a water soluble synthetic dye that is often used as a food colorant. Beside application in drugs and cosmetics, erythrosine is applied for dying many food stuffs including biscuits, chocolate, luncheon meat, sweets, and chewing gums [5]. When excessively consumed, it can cause sensitivity to light, affecting thyroid hormone levels and lead to hyperthyroidism in some cases [1]. The maximum allowed level of erythrosine is 200 mg/kg in some food stuffs [5]. Monitoring and eliminating erythrosine is a necessary job due to its potential toxicity and pathogenicity. The high toxicity of erythrosine was behind many environmental studies to remove this dye from water. Photochemical degradation using TiO2 particles, biochemical degradation, and adsorption by activated www.ijaers.com
carbon/natural adsorbents, were the most applicable procedures. Dyes removal by adsorption technique is often recommended due to the low running costs and no harmful by-products are generated as the case in other destructive procedures. In fact, most food dyes are often present at trace levels (usually in đ?œ‡g or ng levels) in water streams which may retard their direct quantification by most instruments [6]. In this study, the ability of coconut fibre carbon to remove erythrosine by adsorption is been studied. The adsorption capacity of dye will also be examined using the adsorption isotherm technique. The Langmuir, Freundlich RedlichPeterson isotherms will used to fit the equilibrium data. Pseudo-first order, pseudo-second order models, activation energy and the thermodynamic equations will also be used to fit the experimental data [4]. II. MATERIALS AND METHODS 2.1 Preparation of adsorbents Sample of coconut fibre was picked from the environment in Elele, Rivers State, Nigeria. The coconut fibre was washed with tap several times to remove the dust and other water- soluble materials. The process continued until the washing water was colorless. They were respectively dried in the open air. The dried coconut fibre was carbonized in a furnace (SX-5-12) at 400ËšC for 3 hours and the charred coconut fibre was allowed to cool to room temperature. It was chemically activated by weighing 100gram of the ground carbonized coconut fibre in 300 ml of 0.1M HCl solution, thoroughly mixed and heated until it formed slurry. The slurry was transferred to a crucible and heated in a furnace (SX-5-12) at 800ËšC for 3 hours and allowed to cool to room temperature and washed with de-ionized water, dried in an oven (MINO/75/F/DIG) at 110ËšC for 2 hours [3]. 2.2 Preparation of adsorbate Page | 48