Adsorption of Contaminants of Emerging Concern from Aqueous Solutions using Cu2+ Amino Grafted SBA-15 Mesoporous Silica: Multi-Component and Metabolites Adsorption Academic Article uri icon

abstract

  • SBA-15 and Cu2+ amino grafted SBA-15 adsorbents (CuNH2_g_SBA-15) were prepared to investigate the equilibrium and dynamic adsorptive removal of a set of contaminants of emerging concern (CECs; carbamazepine, caffeine, clofibric acid, salicylic acid, and naproxen) from water. Multicomponent and CEC metabolites adsorption was also evaluated to elucidate effects on adsorption capacity and selectivity. Equilibrium adsorption studies showed that CuNH2_g_SBA-15 is capable of removing anionic and acidic CECs even at trace level concentrations. However, multicomponent tests revealed a decrease of 30% in adsorption capacity in the case of the acids. The CuNH2_g_SBA-15 variant was less affected by multicomponent competitive adsorption, probably due to the ability of this adsorbent to interact with CECs through several, simultaneous adsorption mechanisms (i.e., electrostatic interaction, hydrogen bonds, and metal coordination complexes). These were confirmed via X-ray photoelectron spectroscopy (XPS) analyses. Preliminary fixed-bed adsorption tests showed that beds made of CuNH2_g_SBA-15 are prone to mass-transfer resistance in comparison to those made of unmodified SBA-15, causing a decrease in both adsorption capacity and degree of bed utilization. Adsorption of parent/metabolites CEC binary mixtures resulted in a reduction in adsorption capacity of the parent CECs, but the adsorbents showed a remarkable selectivity toward the metabolites, particularly CuNH2_g_SBA-15. In general, this study provides substantial evidence that the anchoring of amine/copper species onto the surface of mesoporous silica may provide a platform for the development of CEC selective adsorbents for water treatment.

publication date

  • 2018