Synthesis and Application of a New Class of Stabilized Nanoscale Iron Particles for Rapid Destruction of Chlorinated Hydrocarbons in Soil and GroundwaterEPA Grant Number: GR832373
Title: Synthesis and Application of a New Class of Stabilized Nanoscale Iron Particles for Rapid Destruction of Chlorinated Hydrocarbons in Soil and Groundwater
Investigators: Zhao, Dongye , Roberts, Christopher B.
Current Investigators: Zhao, Dongye , He, Feng , Roberts, Christopher B.
Institution: Auburn University Main Campus
EPA Project Officer: Hahn, Intaek
Project Period: August 1, 2005 through July 31, 2008 (Extended to July 31, 2009)
Project Amount: $280,215
RFA: Greater Research Opportunities: Research in Nanoscale Science Engineering and Technology (2004) RFA Text | Recipients Lists
Research Category: Hazardous Waste/Remediation , Nanotechnology , Safer Chemicals
The overall goal of this research is to develop a cost-effective, in-situ remediation technology that employs a new class of highly dispersive 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. This research will test the following three key research hypotheses: 1) low concentrations (<0.2% w/w) of select water soluble starches or celluloses can act as dispersants/stabilizers to yield nanoparticles that are resistant to agglomeration and suitable for in-situ injection; 2) the stabilized nanoparticles will offer much greater reactivity and longevity over currently used non-stabilized iron particles for dechlorination of chlorinated hydrocarbons; and 3) the stabilized nanoparticles can move freely in soil pores and can attack and destroy contaminants sorbed in soil micropores.
The research objectives will be achieved through three hypothesis-driven tasks. Task 1 focuses on the synthesis of highly dispersed and stable nanoparticles. The optimal stabilizers will be determined by screening commercial water-soluble starches and celluloses based on effectiveness, environmentally friendliness, and cost. Then mono- and bi-metallic nanoparticles will be synthesized with the aid of selected low-cost and “green” stabilizers. Task 2 will characterize and test the nanoparticles for dechlorination of select chlorinated hydrocarbons such as TCE and PCBs. The particle size, surface area, and long-term stability of the stabilized nanoparticles will be measured with state-of-the-art microscopic, spectroscopic techniques. The dechlorination effectiveness will be tested through a series of bench-scale batch and column degradation experiments in both homogeneous and heterogeneous systems. Task 3 will validate the bench-scale experimental results through pilot-scale testing and test the feasibility of an in-situ remediation process at a nearby contaminated site. A pilot-scale remediation process will be developed based on the nanoparticles and then tested for process effectiveness as well as the fate, transport and potential environmental impacts of the nanoparticles.
This research directly addresses the EPA’s priority need for research “concerning the applications of nanotechnology in... environmental treatment and remediation”. A new class of physically stable, chemically powerful, and environmentally friendly nanoparticles will be synthesized and characterized, and a cost-effective remediation technology based on the new materials will be developed for in-situ destruction of chlorinated hydrocarbons at various contaminated sites. Given the known health risks of chlorinated hydrocarbons, the extent of such contamination and the associated tremendous economical burdens, the resulting technology will benefit millions of affected people and thousands of contaminated sites.