Using ultra filtration membrane in photo electrocatalytic desalination cell (UF-PEDC)

Abstract

Several methods have been invented to desalinate saltwater for industrial or domestic uses, but still, they need to be improved to reduce the cost and environmental impacts. In this study, a desalination cell is inserted in the middle of photoelectrocatalytic cells to separate ions, and drag them into the electrolytes. The driving force, in this method, is ultraviolet illumination, exciting coated titanium nanotubes on the anode electrode, and then produces electron/hole pairs. Holes degrade organic matters, and electrons are transferred by an external circuit to the cathode chamber. Ultrafiltration membrane (UF) is used for the first time as a separator barrier between chambers in this photo redox desalination method. The performance of photo electro desalination cell (UF-PEDC) in different independent parameters like salt content, pH, resistivity, and illumination density is investigated. The UF-PEDC desalinates 42.54% of saltwater with the total dissolved solids (TDS) of 78.57 g/l and also degrades 96.46% of methylene blue as an organic matter after 70 h. This experiment shows that UF-PEDC can operate longer, more efficient, and with a higher TDS removal rate than microbial desalination cells and is a suitable choice to desalinate hypersaline streams produced in reverse osmosis methods.