Adsorption Characteristics of 2,4-Dimethyphenol by Using Zeolite in Aqueous Phase

The adsorption removal of 2,4-dimethyphenol (2,4-DMP) in aqueous phase was investigated by using zeolite in a batch statistic adsorption system. The 2,4-DMP adsorption capabilities of three different zeolites were compared, and FAU-Y zeolite was chosen as the adsorbent for its best adsorption capabilities. The effects of initial pH and adsorbent dosage on 2,4-DMP adsorption were investigated respectively, and the adsorption kinetics and isotherms analyzed. The results showed that FAU-Y zeolite had high adsorption ability for 2,4-DMP. The equilibrium of the adsorption process was established in about 24.0 h under the conditions of initial 2,4-DMP concentration 250 mg/L, initial pH 5.2, FAU-Y zeolite dosage 5.0 g/L and temperature 20 oC, with a saturated adsorption capability of 48.22 mg/g. The initial pH from 2.0 to 9.3 had no significant influence on 2,4-DMP adsorption removal. The comparison of adsorption kinetic models showed that the adsorption process was better described by a second-order adsorption kinetic model. The isotherm analysis showed that the adsorption equilibrium data fit better with Langmuir-Freundlich isotherm than with the Langmuir isotherm and Freundlich isotherm.