497d Nanoscale Iron Remediation of Trichloroethylene Monitored by Microcapillary Microscopy

Tonghua Zheng, Carolina Rojas-Gonzalez, Grace Tan, Jingjing Zhan, Jibao He, Gary L McPherson, Kyriakos Papadopoulos, Yunfeng Lu, and Vijay T. John. Chemical Engineering, Tulane University, 300 Lindy Boggs Bldg, Tulane University, New Orleans, LA 70118

The fate of trichloroethylene (TCE) during degradation by reactive nanoscale iron particles (RNIP) was monitored by a novel capillary microscope technique. The inner surface of a glass capillary was functionalized by octadecyl silane to simulate the real soil environment where TCE is preferentially adsorbed on soil silicate with hydrophobic surface. TCE was injected to the capillary filled with RNIP. The reaction of TCE with RNIP was evaluated through decrease of TCE droplet size as reaction proceeds. The plot of droplet size vs. time reveals the pseudo first order reaction of TCE with RNIP. The gas bubbles (possible ethane or H2) generated during the reaction were observed on TCE/RNIP interface, confirming that the surface plays an important role on the reaction. This research provides important insight for the remediation of TCE by RIPN in the real soil environment. We also discuss novel methods to synthesize RNIP for optimal transport and reaction during in-situ remediation.