A Model for Palladium Catalyzed Destruction of Chlorinated Ethene Contaminated Groundwater
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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Groundwater contamination by chlorinated ethenes is a widespread environmental problem. Conventional remediation technologies have shortcomings that have prompted further research into the development of novel treatment technologies. A palladiumalumina catalyst in the presence of dissolved molecular hydrogen referred to hereafter as a PdH2 system has been demonstrated to rapidly destroy chlorinated ethene contaminated groundwater. First-order kinetics have been used to model chlorinated ethene destruction in a PdH2 reactor. However, catalyst deactivation and regeneration are important processes that also need to be modeled in order to better understand their effect on treatment efficiency. This study presents a model for palladium catalyzed destruction of chlorinated ethenes that includes catalyst deactivation and regeneration. The model is validated using published column experiment results performed at Stanford University. The model is then coupled with an analytical groundwater flow model to simulate application of in-well PdH2 reactors to accomplish subsurface contaminant destruction in a Horizontal Flow Treatment Well HFTW system. Applying the model under realistic conditions results in approximately 130 days of system operation without significant catalyst deactivation. This suggests catalyst deactivation may not significantly affect operating costs or system performance in a real remediation scenario. The model presented in this study, by incorporating the relevant processes of catalyst deactivation and regeneration, represents an important step in transitioning the PdH2 in-well system toward field application.
- Water Pollution and Control