Chemical Science Review and Letters ISSN 2278-6783 Chem Sci Rev Lett 2018, 7(25), 201-213 Article CS192049011 201 Research Article Effective Utilization of Eichhornia Crassipes in Decolourisation of Cationic dyes from aqueous solution S Kalai Selvi 1 * and N Suganthi 2 1 Department of Chemistry, Velalar College of Engineering and Technology, Erode, Tamilnadu, India 2 Department of Chemistry, L.R.G Govt Arts College for Women, Tirupur, Tamilnadu, India Introduction One of the world’s most polluting industries is the textile-dyeing sector, which in Asian nations releases trillions of liters of chemically tainted wastewater. Each year, textile-dyeing industry gulps down trillions of liters of fresh water, together with massive amounts of chemicals. The untreated wastewater from those industries is then dumped into rivers that bring its toxic content to the sea, where it spreads around the globe [1]. Methylene blue (MB) is synthetic aromatic complex, used for many textile and dyeing industries. MB damages eye, on gasp causes headache, acute breathing problems, increases sweating and heart rate. On ingest causes abdominal pain, mild bladder irritation, dizziness, vomiting, stomach upset and frequent urination [2]. Malachite Green (MC) is a cationic dye, used for the textile, paper and leather dyeing industries. It has many medicinal values like antimicrobial in aquaculture to enlarge fish hatchery. It is also used as food coloring and additives in food processing units. In 1992, eating fish containing traces of malachite green as contaminants cause significant health hazards in human being was suggested by Canadian authorities [3]. In June 2007, the Food and Drug Administration (FDA) blocked the importation of several varieties of seafood due to continued malachite green contamination [4]. MC is injurious to eyes, skin, bones, and stomach. On ingestion causes anemia, diarrhea, infertility, abdominal pain and irritation to heart, kidney, stomach and lungs. It also reduces RBC count and raise WBC count, which delays coagulation of blood [5]. In particular, these dyes are synthetic aromatic compounds; which are highly toxic, carcinogenic or mutagenic to life forms [6]. The presence of even very low concentration of dyes makes water highly colored and aesthetically undesirable. Therefore colour should be removed from the effluent before they are discharged. Adsorption with activated carbon has been proved to be an effective and attractive process for the treatment of colored waste water. Countries like India; there is a need to search for a new class of cost-effective materials. In recent years attention has been focused on agricultural waste annually. There are numerous agricultural by products and residues have been proved to remove dyes from aqueous solution [7]. Identifying new, economical, highly effective and abundantly available material is still needed. Eichhornia crassipes (Water hyacinth) constitutes an important part of an aquatic ecosystem. The direct effect of Eichhornia Crassipes on freshwater bodies is its obnoxious smell. It kills the aquatic biota also and depletes oxygen completely from water streams. Water hyacinth as a very promising plant with tremendous application in wastewater treatment is already proved. Water hyacinth is used to treat wastewater from dairies, tanneries, sugar factories, pulp and paper industries, palm oil mills, distilleries, etc [8]. All the efforts of scientists and technocrats all over the world Abstract Adsorption is an ideal alternative technique to other expensive treatment options for removal of colour from wastewaters. In this study Eichhornia Crassipes, an aquatic weed was used as a raw material to prepare activated carbon by various methods according to the standard procedures. The effects of different system variables were studied in the batch tests using Methylene blue and malachite green dyes at different dilutions with the Eichhornia Crassipes carbon. In-order to develop an effective and accurate design for removal of dye, adsorption kinetics and equilibrium data are essential basic requirements. Results of the kinetic studies show that the adsorption reaction is second-order kinetic model. Elovich model and intra particular diffusion corresponding constants were calculated and discussed. Equilibrium isotherms were analyzed by Langmuir, Freundlich and Tempkin isotherms. The adsorption equilibrium data obeyed Langmuir, Freundlich, Tempkin isotherms. Desorption and use of desorbed datas has been obtained. Keywords: Cationic dyes, Eichhornia Crassipes, Adsorption and Isotherm *Correspondence Author: S Kalai Selvi Email: kalaiprony@gmail.com