The adsorption behaviour of safranine O and malachite green oxalate dyes on activated carbon as a function of temperature for a fixed initial concentration was investigated at T = (303, 313 and 323) K and p = 0.1 MPa through adsorption isotherms and their thermodynamic parameters Delta G degrees, Delta H degrees and Delta S degrees. The isotherms were correlated with a new model based on the principle of phase equilibrium. The new model equation comprising of 4 adjustable parameters correlates the isotherms as a function of temperature, sorbate melting temperature. The overall deviation between the experimental and the correlated results was less than 6.85% in averaged absolute relative deviation (AARD). (c) 2017 Elsevier Ltd.