THWRC Awarded Proposal 513TAM0031H

Project number:           513TAM0031H

Title:                              In-Situ Remediation of Hydrocarbon Contaminated

                                      Groundwater Using Polymeric Nanoparticles

Lead PI:                        Gretchen Miller

Awarded amount:        $30,000


Project Abstract

Groundwater contamination by hydrocarbons, particularly petroleum products, is a widespread problem in developed countries. Engineered nanomaterials (ENMs) show promise as a strategy for in-situ remediation of these compounds. Currently, nanoscale zero valent iron (nZVI) is a popular choice for use in permeable reactive barriers targeting chlorinated solvents and polycyclic aromatic hydrocarbons. However, the ideal placement method for these materials, well injection, is difficult due to their transport properties. Recently, a new polymeric nanoparticle was developed by the Wooley Laboratory at Texas A&M University. These magneto shell-cross-linked knedle-like (MSCK) nanoparticles were designed and tested for the recovery of crude oil from surface waters, but may potentially be used to remove petroleum hydrocarbons from porous media.

The objective of the proposed project is to study the effectiveness and viability of MSCKs for the in-situ remediation of petroleum contaminants in groundwater. MSCKs have several properties that make them ideally suited for this task: they are small enough in size to be dominated by Brownian motion and to be mobile in porous media, they have a high loading capacity (10 grams of petroleum per gram of nanoparticle), they may be extracted from water by applying a magnetic field, and they have the potential to be tailored for particular contaminants via pre- or post-assembly modifications of the polymeric component. MSCKs offer many of the same benefits as nZVI, but operate in a fundamentally different manner, with potentially enhanced mobility, recyclability, and selectivity. In order to determine the viability of MSCKs as a remediation tool, we must first ask: How readily are MSCKs transported through porous media? How effective are MSCKs at removing hydrocarbon contaminants in porous media?

In this project, column studies will be conducted using two porous media types (sand and a sand/clay mixture) and one simulated hydrocarbon contaminant (mineral oil). Column effluent will be routed through a flow-through cell for continuous measurements of MSCK concentration using UV-Visible or dynamic light scattering spectrophotometry. Aliquots will be collected at discrete time periods for the extraction of MSCK and mineral oil. A series of experiments will be conducted to: 1) provide a baseline values of hydraulic conductivity and dispervisity for the porous media; 2) determine the behavior of both loaded and unloaded MSCKs, i.e., before and after they incorporate petroleum hydrocarbons into their structure; and 3) characterize the ability of MSCKs to remove dissolved, free-phase, and residual hydrocarbons found in porous media. After completing the proposed research, we will have established the transport and contaminant sequestration and entrapment parameters associated with MSCKs within porous media, which will allow us to decide if further research into this method as a remediation technique is warranted.