Tuesday, 15 October 2019: 16:55
Room 312 (The Hilton Atlanta)
The road salt that is applied to sidewalks, driveways, roads and parking lots makes its way to our local waterways killing freshwater biotas as well as decreasing structures working life through increasing corrosion rates. Recycling road salt is essential to reduce the ever-increasing amounts used in Quebec and Ontario, Canada. Using electrochemical desalination cells is investigated to regenerate the salt. The optimization includes solvent selection, establishing a compact design and increasing the removal rate with as little energy requirement as possible. This paper reports the optimum combined conditions obtained so far. In a 2-compartment cell, Direct Borohydride Fuel Cell (DBFC), based on sodium borohydride (NaBH4) and hydrogen peroxide provided better current and power densities in comparison to Direct Methanol Fuel Cell (DMFC), based on methanol and peroxide. This agrees with several review papers comparing these two fuel cell types. For further testing NaBH4 was substituted with potassium borohydride (KBH4) in a 3-compartment cell, t producing a highly-desalinated effluent. The sodium ions (Na+) and chloride ions (Cl-) were 98.7% and 99.2% removed, respectively. The maximum open circuit voltage (OCV) is 1.49 V, but quickly drops to 1.23 V. Future work includes incorporation of microbes (mixed culture) in the anodic compartment against a variation of several microalgae species in the cathodic compartment such as Desulfovibrio vulgaris, Geobacter sulfurreducens and Shewanella putrefaciens.