Evaluation of the Effectiveness of Hydrophobic Microbeads for Diethyl Phthalate Removal from Aqueous Solution

In this study, hydrophobic poly(divinylbenzene-N-methacryloyl-L-tryptophan methyl ester) [poly(DVB-MATrp)] microbeads (average diameter = 150-200 μm) were used for diethyl phthalate (DEP) removal from aqueous solution. The poly(DVB-MATrp) microbeads were synthesized by suspension polymerization. The microbeads were used for DEP adsorption from aqueous solution to determine the effect of pH, initial DEP concentration, temperature and contact time on the adsorbed amounts of DEP. The effect of initial DEP concentration was investigated in the concentration range of 1–300 mg/L at pH 3.0. The experiments were conducted at three different temperatures (250C, 350C and 45 °C). The maximum DEP adsorption capacity was calculated at 251.3 mg/g at pH 3.0 (25 0C). The adsorbed amount of DEP onto the poly(DVB-MATrp)was decreased with increasing temperature due to the exothermic nature of the adsorption. The kinetic studies demonstrated that the adsorption process reaches equilibrium at around 30 min. The Langmuir isotherm model fitted the adsorption data. The pseudo-first order and pseudo-second order kinetic models were employed to evaluate the adsorption process. The prepared microbeads were repeatedly used forDEP adsorption without a significant change in the adsorption capacity. The poly(DVB-MATrp) microbeads were also effectively used in bottled and tap water samples spiked with DEP.