Synthesis And Adsorption Properties Of Selective Resins For Phenolic Contaminants

Phenolic compounds are aromatic hydrocarbon containing hydroxyl derivatives,which are common organic pollutants in water.Phenolic wastewater has a wide range of pollution,and is an important source of water pollution in the environment.In the present study,a series of selective macroporous weakly basic anion exchange resins for phenols were prepared via the reaction of chloromethylated PS-DVB copolymer beads with diethylamine according to the principles of molecular imprinting technique.Two resins LP2 and LP3 were obtained with catechol as a template molecule in water or cyclohexane reaction system,respectively.Using the same method,JP2 and JP3 resins were prepared with resorcinol as a template molecule,while the reference resin P1 also synthesized without any template molecule.The structural and surface parameters of the resin were characterized by Fourier transform infrared spectroscopy and specific surface analysis.The adsorption properties of the resins were investigated by using catechol,resorcinol and hydroquinone as adsorbates.Langmuir isotherm model could better describe the adsorption process of catechol,resorcinol and hydroquinone on all the studied resins.The pseudo second order kinetics model could well describe the adsorption kinetics of the catechol on the resins.The sulfate and chloride ions contained in solutions had negative effects on the adsorption properties of the resins.The mixture of sodium hydroxide and ethanol could effectively remove the adsorbed resin.The results of competitive adsorption experiment showed that the selectivity of the new resins for the target compounds was better than that of the reference resin.In the catechol/resorcinol system,the selectivity coefficients for catechol of LP2 and LP3 were 2.0843 and 1.9451 times that of P1 respectively,while the selectivity coefficients for resorcinol of JP2 and JP3 were 3.0908 and 1.2588 times that of P1.When the competitive substance was hydroquinone,the selectivity ratios for catechol of LP2 and LP3 were 3.6877 and 1.1744 times that of P1,and the selectivity ratios for resorcinol on JP2 and JP3 were 1.2782 and 1.4434 times that of the reference resin.The results of dynamic adsorption experiments showed that the Yoon-Nelson and Thomas model could simulate the adsorption breakthrough curves of catechol in the resin layer and the adsorption performance of the LP3 was better than the reference resin P1.