World Journal of Chemistry 10 (1): 11-17, 2015 ISSN 1817-3128 © IDOSI Publications, 2015 DOI: 10.5829/idosi.wjc.2015.10.1.22207 Corresponding Author: O.L. Adebayo, Department of Chemistry, College of Education, Ikere, Ekiti State, Nigeria. 11 Assesment of Ground Nut Husk as a Sorbent in the Decolourization of Congo Red Contaminated Aqueous Medium O.L. Adebayo, O.T. Ogunmodede and O.I. Ojo 1 2 1 Department of Chemistry, College of Education, Ikere, Ekiti State, Nigeria 1 Department of Chemical Sciences, Afe Babalola University, Ado Ekiti, Nigeria 2 Abstract: Groundnut husk is a common agricultural waste in Nigeria and it’s used as an adsorbent for the removal of congo red (CR) from aqueous system. The present study investigated the ability of groundnut husk to abstract congo red (CR) from aqueous solution. The process of sorption of Congo red from solution was analysed using 2 different isotherm models (Langmuir and Freundlich, isotherm equations). The highest values of r were obtained when the experimental data were fitted into Freundlich equation (0.984). The sorption of 2 Congo red by groundnut husk was found to be affected by the sorbent dose, temperature, pH and initial Congo red concentration. The kinetic data showed that the sorption capacity of groundnut husk for the congo red increased with increasing initial dye concentration, while a reverse trend was observed when the effect of sorbent dosage was studied. Analysis of the data obtained from the different sorption studies revealed that the data fitted better to the pseudo-second order model than pseudo first order kinetic model, indicating that the sorption process will include chemisorptions of congo red on groundnut husk. Key words: Congo red Groundnut husk Adsorption Kinetic Pseudo Orders Monolayer INTRODUCTION effectiveness and versatility [4]. However, the use of Many industries, such as textile, dyestuff limited because of its high cost and difficulty in manufacturing, leather tanning, food preparation, paper regeneration [5]. In recent years, the use of soil clay kiproduction and printing, use dyes that produce highly materials to replace commercially available adsorbents has colored waste effluents. These dyes can consume the become popular because of their low cost, ready dissolved oxygen required by aquatic life and some of availability, lack of toxicity and potential for ion exchange them are directly toxic to microbial populations and can [6]. Their unique properties, such as a high specific even be carcinogenic to mammals [1]. In addition, dyes are surface area and surface chemistry for example, give these resistant to light and moderate oxidative agents, so they materials a broad range of applications [7]. In the present cannot be completely removed by conventional biological study, the use of groundnut husk in the attenuation of a treatment processes, such as activated sludge or model anionic dye (CR) in an aqueous stream shall be anaerobic digestion [2]. A wide range of methods has explored. been developed and used for the removal of dye contaminants from wastewater. These technologies MATERIALS AND METHODS involve adsorption on inorganic matrices, decolorization by photocatalysis and/or oxidation, microbiological or Sorbate Preparation: The dye used in the present enzymatic decomposition and so on [3]. Adsorption has studies, CR (C.I. 2212), chemical formula = C H N Na O been recognized as the most popular treatment process ( max = 500 nm) was accurately weighed and dissolved in for the removal of non-biodegradable organics from distilled-deionised water to prepare the stock solution aqueous systems, with activated carbons being the most (500 mg L ). Different working solutions were prepared common adsorbent for this process because of their from the stock solution by serial dilution. this type of adsorbent in wastewater treatment is still 32 22 6 2 1