Reductive Removal of Nitrate and Trace Contaminants From Water Using Metal CatalystsEPA Grant Number: FP916417
Title: Reductive Removal of Nitrate and Trace Contaminants From Water Using Metal Catalysts
Investigators: Davie, Matthew G.
Institution: Stanford University
EPA Project Officer: Jones, Brandon
Project Period: January 1, 2004 through December 31, 2006
Project Amount: $111,688
RFA: STAR Graduate Fellowships (2004) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Fellowship - Environmental Engineering , Engineering and Environmental Chemistry
The overall objectives of this research are to develop Pd/M/support catalysts for denitrification of nitrate to dinitrogen and removal of trace contaminants and to examine the catalysts’ performance under groundwater treatment conditions. The project is executed in two complementary parts, one at the University of Illinois at Urbana-Champaign (UIUC) and the other at Stanford University. UIUC will develop and test catalysts for nitrate removal and develop a pilot-scale process for nitrate removal. My research at Stanford will focus on testing catalysts for trace contaminant reduction, determining matrix effects on reduction, and optimizing and designing a field reactor. During the next year, research will target three tasks: (1) synthesis and characterization of Pd/M/support catalysts for nitrate reduction; (2) measurement of nitrate reaction activity and selectivity using different catalysts in distilled water, synthetic and natural groundwater, and in the presence of co-contaminants; and (3) development of a model for deactivation and regeneration.
To complete Task 1, colloidal catalysts will be synthesized and loaded onto various supports, such as activated carbon fibers and ion exchange fibers. X-ray diffraction may be used to quantify the size of reactive metal sites on various supports. Task 2 will involve using the various catalysts generated in Task 1. The effects of catalyst poisoning and regeneration on nitrate reduction activity and selectivity will be evaluated. All new catalysts will be initially tested using a batch system, with promising catalysts then tested over longer time periods in a flow-through system. Task 3 will improve understanding of the deactivation and regeneration processes. The reversibility of sulfide deactivation will be tested by exposing catalysts to sulfide for a few days, then switching to a deionized water feed and monitoring activity over time. Additionally, sulfide deactivation will be characterized through pH-controlled experiments to determine the contributions of hydrogen sulfide and bisulfide. Once the impacts of sulfur on catalyst activity are understood, catalyst activity towards other trace contaminants like arsenate, chromate, and selenate, or organics such as N-nitrosodimethylamine, pesticides, and halogenated disinfection byproducts will be tested.