Pre-Concentration for Improved Long-Term Monitoring of Contaminants in Groundwater

Materials for the concentration of nitroenergetic targets from groundwater are sought for monitoring and remediation applications. For this work, periodic mesoporous organosilicas incorporating diethylbenzene bridges in their pore walls were applied for the adsorption of nitroenegetic targets from aqueous solution. The materials were synthesized by co-condensing precursors to improve structural characteristics. Molecular imprinting of the pore surfaces was employed through the use of a novel target-like surfactant to further enhance selectivity for targets of interest nitroenergetics and their breakdown products over targets of similar structure p-cresol and p-nitrophenol. The impact of variations in precursor ratios and amounts of imprint molecule was evaluated. These results were applied to the development of materials possessing organization on both the meso and macro scales. The incorporation of macropores provides a material with enhanced flow through characteristics, thereby reducing back pressure when used in column formats. Concentration of targets from soil sample extracts using these materials was demonstrated.