Diethyl phthalate removal from aqueous phase using poly(EGDMA-MATrp) beads: kinetic, isothermal and thermodynamic studies

Abstract

In this study, poly(ethylene glycol dimethacrylate-N-methacryloyl-l-tryptophan methyl ester) [poly(EGDMA-MATrp)] beads (average diameter = 106–300 µm), which were synthesized by co-polymerizing of N-methacryloyl-l-tryptophan methyl ester (MATrp) with ethylene glycol dimethacrylate (EGDMA), were used for diethyl phthalate (DEP) adsorption. The various factors affecting the adsorption of DEP from aqueous solutions such as pH, initial concentration, contact time and temperature were analysed. Adsorption behaviour of DEP on the poly(EGDMA-MATrp) beads was investigated by varying pH values of solution, contact time, initial concentration and temperature. An optimum adsorption capacity of 590.7 mg/g for DEP was obtained at 25 °C. The present adsorption process obeyed a pseudo-second-order kinetic model. All the isotherm data can be fitted with the Langmuir, Freundlich and Dubinin–Radushkevich isotherm models. Thermodynamic parameters ΔH = 7.745 kJ/mol, ΔS = 81.92 J/K/mol and ΔG = −16.69 kJ/mol to −18.31 kJ/mol with the rise in temperature from 25 °C to 45 °C indicated that the adsorption process was endothermic and spontaneous.

Keywords:

• diethyl phthalate
• removal
• adsorption
• endocrine-disrupting compounds
• polymer

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

This work was supported by the Research Foundation of Uludag University (Project No: KUAP(F)-2012/58 and OUAP-(F)-2012/28).

Supplemental data

Supplemental data for this article can be accessed at 10.1080/09593330.2015.1006687.