In this study, the removal of nitrite from aqueous solution by adsorption was investigated. Sepiolite and powdered activated carbon (PAC) were used as adsorbents. In order to investigate the adsorption mechanisms, three simplified kinetic models, i.e., pseudo-first-order, pseudo-second-order and intraparticle diffusion were applied to fit the kinetic data obtained by using sepiolite and PAC. The rate constants for the three models were determined and the correlation coefficients were calculated. Adsorption followed pseudo-second-order rate kinetics for both sepiolite and PAC. © 2008.