Abstracts

study the sensitivity of large scale, commercial applications of STAR to site conditions
and system design parameters. One study, focused on in situ applications, is calibrating the
model to a field pilot test which will then be used for sensitivity simulations that are exploring
permeability, coal tar saturation, injected air pressure, and location of the air injection
well screen to study the effect on the speed and ultimate extent of remediation. A second
study, focused on ex situ applications, is evaluating the influence of reactor design and soil
mixing heterogeneity on the success of batch treatment of excavated soils by STAR. In
partnering with Savron, the company that is commercializing the STAR technology, the
findings of this work will enhance the optimization of STAR for rapid and cost effective
soil remediation, as well as help identify limits to its application.
164 - Feasibility of Liquid Phase Metallic Catalyzed Reductive
Hydrodechlorination of 1,2-DCA by Sodium Borohydride as
Hydrogen Donor
Omneya El-Sharnouby 1 , Denis M. O’Carroll 1, 2 , Jose Herrera 1 , & Hardiljeet Boparai 1
1
Department of Civil and Environmental Engineering- Western University, London,
Ontario, Canada
2
School of Civil and Environmental Engineering, University of New South Wales, Manly
Vale, New South Wales, Australia
1,2-Dichloroethane (1,2-DCA, C 2
H 4
Cl 2
), a probable human carcinogen, is a chlorinated
organic compound (COC) used for the synthesis of vinyl chloride. Due to improper handling,
storage and/or disposal, it has caused widespread subsurface contamination. Chemical
reduction by nano zero valent iron or bimetallic particles systems has been reported
to be capable of degrading many COCs. However, although thermodynamically feasible,
to date metal based reduction of 1,2-DCA has not been shown. Gas phase catalyzed reductive
hydrodechlorination is reported to effectively dechlorinate a wide variety of COCs
including 1,2-DCA using hydrogen gas as reductant, and catalysts for hydrogen activation
and reaction surface. However, the process is carried out at high temperatures (+200 º C),
making it impractical for contaminated field sites applications. Recently, liquid phase catalyzed
reductive hydrodechlorination has emerged as a field applicable technology showing
promising results in reducing COCs. Nonetheless, bench scale studies lack information on
liquid phase catalyzed hydrodechlorination of 1,2-DCA. Therefore, in this study the feasibility
of liquid phase catalyzed reductive hydrodechlorination of 1,2-DCA using sodium
borohydride as a hydrogen source over different catalysts is investigated. Using the gas
phase hydrodechlorination process as an example, Pd, Cu, Cu/Pd, and Ni, were the chosen
catalysts. For the first time, effective liquid phase hydrodechlorination of 1,2-DCA on Pd
and Ni is achieved. 1,2-DCA degradation profiles, and reaction kinetics are explained.
Mechanisms and products are discussed along with likely degradation pathways. Effect of
the different catalysts on the degradation efficiency as well as the different loadings, and
formulations are also presented.
IAH-CNC 2015 WATERLOO CONFERENCE
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