In order to investigate the mechanism of adsorption of reactive dyes from the textile industry on ash from heating plant produced by brown coal combustion, some characteristic sorption constants are determined using Langergren adsorption equations for pseudo-ﬁ rst and pseudo-second order. Combined kinetic models of pseudo-ﬁrst order and pseudo-second order can provide a simple but satisfactory explanation of the adsorption process for a reactive dye. According to the characteristic diagrams and results of adsorption kinetic parameters of reactive dyes on ashes, for the applied amounts of the adsorbents and different initial dye concentrations, it can be concluded that the rate of sorption is fully functionally described by second order adsorption model. According to the results, the rate constant of pseudo-second order decreases with increasing initial dye concentration and increases with increasing amount of adsorbent – ash.
 Aksu, Z., Tatli, A. & Tunc, O. (2008). A comparative adsorption/biosorption study of Acid Blue 161: Effect of temperature on equilibrium and kinetic parameters, Chemical Engineering Journal, 142, 23–39.
 Degs, Y.A., Khraisheh, M.A., Allen, S.J. & Ahmad, M.N. (2000). Effect of Carbon Surface Chemistry on the Removal of Reactive Dyes from Textile Efﬂuent, Water Research, 34, 927–935.
 Qin, Q., Ma, J. & Liu, K. (2009). Adsorption of anionic dyes on ammonium-functionalized MCM-41, Journal of Hazardous Materials, 162, 133–139.
 Tan, I.A.W., Ahmad, A.L., Hameed, B.H. (2008). Enhancement of basic dye adsorption uptake from aqueous solutions using chemically modiﬁed oil palm shell activated carbon, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 318, 88–96.
 Ozcan, A., Oncu, E.M. & Ozcan, A.S. (2006). Kinetics, isotherm and thermodynamic studies of adsorption of Acid Blue 193 from aqueous solutions onto natural sepiolite, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 277, 90–97.
 Ip, A.W.M., Barford, J.P. & McKay, V.G. (2010). A comparative study on the kinetics and mechanisms of removal of Reactive Black 5 by adsorption onto activated carbons and bone char, Chemical Engineering Journal, 157, 434–442.
 Annadurai, G., Ling, L.Y. & Lee, J.F. (2008). Adsorption of reactive dye from an aqueous solution by chitosan: isotherm, kinetic and thermodynamic analysis, Journal of Hazardous Materials, 152, 337–346.
 Senthilkumaar, S., Kalaamani, P., Porkodi, K., Varadarajan, P.R. & Subburaam, C.V. (2006). Adsorption of dissolved Reactive red dye from aqueous phase onto activated carbon prepared from agricultural waste, Bioresource Technology, 97, 1618–1625.
 Özacar, M. & Sengil, I.A. (2005). A kinetic study of metal complex dyes sorption onto pine sawdust, Process Biochemistry, 40, 565–572.
 Özacar, M. & Sengil, I.A. (2004). Application of kinetic models to the sorption of disperse dyes onto alunite, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 242, 105–113.
 Bulut, E., Ozacar, M. & Sengil, I.A. (2008). Equilibrium and kinetic data and process design for adsorption of Congo Red onto bentonite, Journal of Hazardous Materials, 154, 613–622.