(76c) Nitrate Reduction By Catalytic Hydrogenation: Controlling Hydrogen Delivery with Nano-Enabled Polymeric Hollow Fibers

Authors: 
Levi, J., Arizona State University
Guo, S., Rice University
Kavadiya, S., Washington University in Saint Louis
Yin, Y., Rice University
Atkinson, A. J., Arizona State University
Holman, Z., Arizona State University
Rittmann, B., Arizona State University
Wong, M. S., Rice University
Garcia-Segura, S., Arizona State University
Westerhoff, P., Arizona State University
As a result of anthropogenic nitrogen fertilizer inputs, nitrate concentrations in surface and ground waters have dramatically increased during the last century. To minimize the adverse health impacts of nitrate, the World Health Organization has set a recommended maximum contaminant level (MCL) of 50 mg/L NO3− (∼11 mg/L as N-NO3−) in drinking water. Catalytic hydrogenation emerges as abiotic treatment with potential application as point-of-use treatment to reduce nitrate to innocuous nitrogen. Past research of our group identified bimetallic nanocatalysts of In-Pd as promising catalyst due to its high catalytic activity and close to 100% selectivity towards nitrogen gas. However hydrogen delivery remains as technology barrier for implementation. This work explores the nano-enabling of polymeric hollow fibers with In-Pd catalysts and their use in continuous flow reactors for nitrate remediation. The delivery control of hydrogen through hollow fibers overcome the risks associated to direct hydrogen bubbling reactors and diminishes physical-foot print needs. Different coating and nanoparticle attachment technologies are evaluated under long-term performance in terms of (i) nitrate reduction catalytic activity, (ii) selectivity towards nitrogen, and (iii) stability of coatings from leaching.