MATTER: International Journal of Science and Technology ISSN 2454-5880 © 2017 The author and GRDS Publishing. All rights reserved. Available Online at: http://grdspublishing.org/ 93 Agarwal et al. Volume 3 Issue 2, pp. 93-104 Date of Publication: 18 th September 2017 DOI-https://dx.doi.org/10.20319/mijst.2017.32.93104 ADSORPTION ISOTHERM STUDY FOR THE REMOVAL OF NICKEL IONS FROM AQUEOUS SOLUTION USING THERMAL POWER PLANT FLY ASH Agarwal A K Assistant Professor, Visvesvaraya National Institute of Technology, Nagpur, India agarwal_rkn@redifmail.com Muthreja I L Associate Professor, Visvesvaraya National Institute of Technology, Nagpur, India muthreja2158@rediffmail.com Kadu M S Professor, Shri Ramdeobaba College of Engineering and Management, Nagpur, India mahendra.kadu@rediffmail.com Pandhurnekar C P Assistant Professor, Shri Ramdeobaba College of Engineering and Management, Nagpur, India chand2873@gmail.com Abstract In the present study the adsorption of nickel ions on the surface of fly ash was investigated. The batch adsorption experiments were performed at constant room temperature 25±1 0 C using Atomic Absorption Spectroscopy (AAS) Technique. Three adsorption isotherms such as Temkin, Harkins Jura and Brunauer-Emmett-Teller (BET) were used to analyze the results obtained from the experiments. The coefficient of correlation (R 2 ) was determined for each isotherm model to establish the best fit adsorption isotherm model. To carry out the error analysis of the three adsorption isotherm models Chi-square test (Ʃχ 2 ) was used. It was concluded from the laboratory investigations and analysis that BET adsorption isotherm is best fit adsorption isotherm as per linear coefficient of correlation and by non linear Chi square test (Ʃχ 2 ). Keywords