a new temperature effect model to predict benzoic acid isotherm curves onto activated carbon

the recovery and removal of the most organic acids in liquid solutions is usually treated with fixed-bed adsorption processes. among many adsorbents, granular activated carbon (gac) is used to remove organic pollutants such as benzoic acid (ba) from wastewaters conventionally. in this research, adsorption isotherm curves of ba onto gac at varying temperatures 25-60 °c are developed and the amounts of ba concentration in feed fluid and on the adsorbent are obtained. the results show that radke and prausnitz (ra-pr) model among five applicable isotherm models has best fitting with experimental data. in this paper, for the first time, a new model for temperature effect on isotherm curve of ba is investigated. this model could predict isotherm curves in accordance to the isotherm curve in reference temperature with absolute relative error (are) less than 1.2%. thus temperature effect term (t.e.t) model is able to predict isotherm curves only by using experimental data in one temperature successfully. furthermore t.e.t and ra-pr models jointly, could predict the every isotherm curve only with experimental data in three equilibrium points in one temperature with low error. in this case, the average a.r.e% in comparison with experimental data is less than 1.4%.