Resin Adsorption Of Phenol By Endocrine Disruptors

The behaviours of different resins in the adsorption of phenolic compounds were analysed to identify the mechanism controlling the process and to select the optimal resins to removal phenolic compound from aqueous solutions. According to the characterization of phenolic compounds, hyper-crosslinked resins (MN-200, NDA-150) and aminated resins (MN-100, MN-150) were chosen for adsorption of Bisphenol A and Nonylphenol polyethoxylates (NPEOn,n=10,14,30). The main study content was listed as follows: 1. Adsorption of NPEOn(n=10,14,30) onto the four resinsAmony the four resins, MN-200 presented the largest adsorption capacity of NPEOn(n=10,14,30), and those of NPEOn on the NDA-150, MN-100 and MN-150 resins have no obvious difference. The adsorption capacity of NPEOn was larger for surfactants with shorter EO chains than longer EO chains, which indicated that the hydrophobic interactions and steric hindrance played an important role. The results showed that adsorption of NPEOn were dominated by surface area and pore size distribution, and no obvious correlation with the functional groups. The adsorption isotherms of NPEOn fitted the Langmuir and double Langmuir models well. Adsorption dynamics confirmed that the adsorption process involved two plateaus which were attributed to the formation of a monolayer and a bi-layer. Finally, the elution process was investigated to further establish the appropriate adsorption conditions for the purification. 2. Comparison of adsorption of the three phenolic compoundsComparing the adsorption of Phenol, Bisphenol A and NPEO10, MN-200 presented the largest adsorption capacity for the three phenolic compounds, indicating that the interactions between the phenolic compounds and the surface of resins, especial microspore surface area and pore size distribution, were the key factors to their adsorption affinity. The adsorption affinity of Bisphenol A was higher than that of phenol and NPEO10, which may be ascribed to its lower value of water solubility andπ-πinteraction between Bisphenol A and the resin with benzene rings, so the values of adsorption coefficients Kd was higher. The thermodynamic results showed that the adsorption of Bisphenol A and NPEO10 was thermodynamically favorable and generally endothermic whereas the adsorption process of phenol was exothermic. The adsorption amounts of phenol and Bisphenol A had a similar trend to the function of pH values; the adsorption amounts of NPEO10 remain practically constant within the tested pH range, indicating that there could be different interactions contributing to their adsorption process.