Poll Res. 37 (2) : 435-440 (2018) Copyright © EM International ISSN 0257–8050 *Corresponding author’s email: kartika.rathore2012@gmail.com ADSORPTIVE REMOVAL OF CRYSTAL VIOLET DYE FROM AN AQUEOUS SOLUTION USING GUAR GUM - G - POLY (METHYL METHACRYLATE) SUPERABSORBENT NANOCOMPOSITE KARTIKA RATHORE 1 * AND SANGEETA LOONKER Applied and Environmental Chemistry Laboratory, Department of Chemistry, Jai Narain Vyas University, Jodhpur 342 011, Rajasthan, India (Received 16 November, 2017; accepted 25 December, 2017) ABSTRACT In this paper, we report use of guar gum-g-poly (methyl methacrylate) superabsorbent nanocomposite for the removal of crystal violet dye. The adsorption experiments were carried out using batch technique at different pH values. UV-Visible spectrophotometry was used for determination of dye concentration. Result indicates that prepared composite showed highest percentage removal of 78% at pH value of 8. The effect of various variables such as adsorbent dose, initial crystal violet dye concentration, time of contact and pH on percentage removal of dye was investigated. The adsorption isotherms were studied to evaluate adsorption characteristics of nanocomposite used. The study of adsorption isotherm shows that adsorption process of crystal violet follow both Freundlich and Langmuir isotherm. The kinetics of adsorption was also studied and result shows that it follows pseudo second order reaction kinetics. KEY WORDS : Crystal violet dye, Superabsorbent, Nanocomposite, Adsorption, Isotherm, Guar gum, Kinetics INTRODUCTION Industry is a huge source of water pollution. It produces pollutants that are extremely harmful to human beings and the environment. The coloured waste materials discharged from many industries contains toxic heavy metals, dyes, textile, paper, plastic, plating and mining industries produces considerable polluted water. The pollutants must be removed from wastewater before discharging it into the environment. The adsorption process can be used for the removal of dye contaminations from aqueous environments. This process is inexpensive and simple method (Kiani et al., 2011). In the last few years, the removal of dyes from industrial effluents has been given much more attention not only because of their potential toxicity, but also due to their damaging nature to environment (Salleh et al., 2011; Fan et al., 2012; Ali et al. , 2012; Tang et al. , 2013). In addition, the presence of these dyes even at a very low concentrations can pollute a large water body which not only affects aesthetic nature but also reduces sunlight penetration and photosynthesis processes. They may also cause some adverse effects such as, allergy, dermatitis, skin irritation, cancer and mutations in humans (Gokturk et al., 2008; Zhang et al., 2008; Yao et al., 2013). Therefore, dye removal has been a very important but challenging research area of wastewater treatment. The presence of dying effluent in a watercourse has a serious environmental impact. Dyeing effluent has high biological oxygen demand (BOD; measure of organic matter in effluent and oxygen required by bacteria in respiratory process to break down the organic matter) (Blackburn, 2004). Physico-chemical processes such as electrocoagulation, ozonation, photocatalysis, membrane filtration and adsorption have been employed for the treatment of dye containing wastewater. Among these technologies, adsorption process is considered to be promising technology which involves phase transfer of dye