Nitrate Imbalance-control by TRAnsformative Technologies that are Electrochemically-driven

ended

Efficient management of nitrogen cycle imbalance is a critical need of this century. Water with elevated NO3- level is harmful to human and environmental health. Conventional treatment has limitations for point of use treatment and may generate sludge and/or brine solutions. Electrochemical processes are transformative chemical-free technologies that can reduce NO3- to innocuous N2 without sludge production. However, further research in efficient electrocatalysts and scale-up is required for technology implementation. In this project, research aims to overcome challenges of nitrate electrochemical remediation in three phases: (i) nano-electrocatalyst synthesis and benchmarking, (ii) reactor design/construction and evaluation in actual water matrices, (iii) study of alternative electrocatalyst materials. First, different electrodic materials will be evaluated in terms of kinetic reduction and selectivity towards N2. I hypothesize that application of nanoparticle binary and tertiary Pt/Pd alloys with other metals (Cu, Sn, In) will lead to higher N2 selectivity and enhanced electrochemical reduction because the preferential performance characteristics of different metals combined into one electrode material. Use of nanoparticles in tridimensional modified electrodes will improve mass transfer towards/from electrode surface increasing treatment performance as well as reduce catalyst mass requirement. Second, design and construction of different electrochemical reactors for nitrate remediation will catalyze the development of electrochemical technology towards implementation. Reactors will be assessed from the treatment of actual water matrices (brine, groundwater, tap and surface water) and techno-economic analysis. Last, catalysts based on cheaper metal oxide semiconductors will be explored as alternative electrocatalysts to reduce capital costs associated to material selection. Electrocatalytic properties will be benchmarked by scanning electrochemical microscopy.