Grantee Research Project Results
Dongye (Don) Zhao
Auburn University, Auburn, AL
The overall goal of this research is to develop a cost-effective, in situ remediation technology that employs a new class of dispersed iron-based nanoparticles for the rapid destruction of chlorinated hydrocarbons in soil and groundwater. The specific objectives are to: (1) synthesize a new class of stabilized iron-based nanoparticles using low-cost and "green" stabilizers such as starches and celluloses; (2) test the effectiveness of the stabilized nanoparticles for dechlorination of select contaminants (TCE and PCBs) in soil and groundwater; and (3) test the feasibility of an in situ remediation process that is based on the nanoparticles.
Our preliminary data showed that a water-soluble or sodium carboxymethyl cellulose (CMC) can serve as the dispersant to stabilize palladized iron (Fe-Pd) nanoparticles. Compared to non-stabilized Fe-Pd particles, the stabilized nanoparticles displayed markedly improved physical stability, soil dispersibility, chemical reactivity, and reactive longevity. Column tests showed that the stabilized nanoparticles can be readily dispersed in a loamy-sand soil and then be recovered completely. Batch dechlorination tests demonstrated that the CMC-stabilized nanoparticles degraded TCE 29 times faster than non-stabilized counterparts based on the pseudo first-order rate constant.