Photo-Electrodialysis for Brackish Water Desalination: A Life Cycle Sustainability Assessment from Experimental Insights

Abstract

Enhancing the sustainability of freshwater generation through electrodialysis (ED) can be achieved by integrating this process with readily available solar energy. Photo-ED consists of adding a photoactive coating on one of the electrodes to facilitate ion transport when exposed to light. In this study, an experimental and life cycle assessment investigation has been conducted on a conventional ED and photo-ED system to desalinate brackish water. The energy requirements for photo-ED and conventional ED are found to be 4.31 and 4.57 kWh m⁻³, respectively. Most of the life cycle impact assessment results for photo-ED desalination are found to be lower than conventional ED at 1.47 kg CO₂ eq m⁻³, 8.36 × 10⁻⁴ kg PM2.5 eq m⁻³, 0.01 m³ m⁻³, 5.24 × 10⁻⁶ kg P m⁻³, 2.69 × 10⁻³ kg SO₂ eq m⁻³, and 0.37 kg 1,4 DB eq m⁻³ for the climate change (CC), fine particulate matter formation (FPMF), freshwater consumption (FWC), freshwater eutrophication (FWE), terrestrial acidification (TA), and terrestrial ecotoxicity (TE) impact categ, respectively. A sensitivity analysis is also conducted to observe how various electricity inputs and lifetimes of the components affect the selected environmental impacts.