Abstract:
This study investigated adsorption efficiencies of MIL-53(Al) and amine NH2 functionalized MIL-53 (Al) (NH2-MIL-53 (Al)) for removal of ketoprofen (KET) Naproxen (NPX) and ibuprofen (IBP). Selective adsorption and the effects of dissolved organic matter (DOM) hydrophilic DOM (HPI) and hydrophobic DOM (HPO) were evaluated. The adsorption kinetics of MIL-53(Al) were fitted with the pseudo-second-order equation. The Pharmaceuticals (PPCPs) can be adsorbed rapidly within 30 minutes, faster than PAC, and reach equilibrium within 75 min. The NH2-MIL-53 (Al) could not adsorb PPCPs due to the interference of phosphate. Adsorption isotherm of KET, NPX, and IBP on MIL-53(Al) had higher capacity than PAC and can be fitted with the Sip, linear, and Langmuir model, respectively. In mixed solute, adsorption capacities of PPCPs on MIL-53 (Al) were decreased which might be caused by competition for adsorption site, related to the molecular size of PPCPs. In wastewater, the adsorption capacity of PPCPs on MIL-53 (Al) and NH2-MIL-53 (Al) was increased compared with synthetic wastewater due to the increase of breathing effect and decrease of effect from phosphate buffer. Effects of DOM on the adsorption of KET, NPX, and IBP in a single solution were investigated. The adsorption capacity of KET was increased with the presence of DOM, HPI, and HPO; however, the adsorption capacity of NPX and IBP was decreased and/or unchanged which might relate to the interaction of HPO (or HPI) and NPX (or IBP) in solution. In the case of mixed PPCPs with DOM or HPI, the adsorption capacity of PPCPs was decreased due to competition for adsorption sites. The presence of HPO in mixed solution did not show a significant change of the adsorption capacity of three PPCPs on MIL-53 (Al). In case NH2-MIL-53(Al), adsorption capacities of three PPCPs were decreased due to pore blocking by NH2.