International Journal of Engineering Research and General Science Volume ř, Issue Ř, March-April, ŘŖŗ5 ISSN 2091-2730 877 www.ijergs.org Kinetics study of Cr(III) Adsorption onto low cost Fly Ash Adsorbent Dr.V.Chitradevi 1* , S.Mothil 2 1* Associate Professor Department of Chemical Engineering Kongu Engineering College Perundurai-6380582, India erchitrasuresh@gmail.com 2 PG Scholar Department of Chemical Engineering Kongu Engineering College Perundurai -638052, India smothil666@gmail.com Abstract- Chromium removal from wastewater is becoming increasingly important both to meet discharge consents and prevent eutrophication of water resources. A series of simple batch tests were conducted to investigate the influence of fly ash dosage on chromium adsorption from synthetic wastewater containing Chromium trioxide. Chromium removal of up to 84.5% was obtained. Different adsorption and kinetic models were studied namely; Langmuir, Freundlich, First order, Second order, Factorial power and Elovich and their constants were calculated. Using K L values, it is known that adsorption fits well in Langmuir isotherm. Second order kinetics is observed for the adsorption process carried out. Activated Fly ash is used in the treatment process. The effect of various parameters such as initial pH, contact time, adsorbent amount and initial Cr (III) concentration are studied. Adsorption capacity and adsorption intensity were calculated. Rate constants and order of the reaction were determined and final rate equation was developed. Keywords: Chromium removal, Chromium trioxide, Adsorption, Activated Fly ash, Adsorption capacity, Adsorption intensity. INTRODUCTION Advances in science and technology have brought tremendous progress in many spheres of development, but in the process, also contributed to degradation of environment all over the globe due to very little attention paid to the treatment of industrial effluents [1] . The discharge of non-biodegradable heavy metals like Cu, Zn, Ni, Pb, Cd, and Cr into water stream is hazardous because the consumption of polluted water causes various health problems. Among these heavy metals, pollution by chromium is of major concern as chromium and its compounds are widely used in many industries such as metal finishing, dyes, pigments, inks, glass, ceramics, chromium tanning, textile, dyeing and wood preserving industries and certain glues [2] . Leather is a material that has a reasonable mechanical resistance, good chemical stability and acceptable thermal behavior. This material is obtained by means of specific reactions among carboxylic groups of the protein fiber network of animal skin (collagen) and tanning reagents. The basic chromium (III) sulfate [Cr(OH)(H 2 O) 5 SO 4 ] is a primary tanning agent widely used at the present time [3] . Chromium exists in +3 and +6 oxidation states, as all other oxidation states are not stable in aqueous solutions. Both valences of chromium are potentially harmful [4] .When chromium enters the gastric system, epigastric pain, nausea, vomiting, severe diarrhea, corrosion of skin, respiratory tract and lung carcinoma are noticed. The discharge limit from industry is less than 1 mg/l. Chromium is hazardous to health when its limit in potable water exceeds 0.5 mg/l. Several methods such as chemical precipitation, ions exchange, electrochemical precipitation, solvent extraction, reverse osmosis are being practiced for chromium removal in waste waters [5] . These methods are cost intensive and are unaffordable for large scale treatment of wastewater that is rich in chromium. Adsorption using the activated carbon is an effective method for the treatment of industrial effluents contaminated with chromium and quite popular as compared to other methods [6] . The cost associated with the commercial activated carbon is very high which make the adsorption process expensive [7] . This indicates that the cost effective alternate adsorbents for treatment of chrome contaminated waste streams are needed.