Life cycle assessment of environmental impacts and energy demand for capacitive deionization technology

Assessment of life cycle environmental impacts and cumulative energy demand on a laboratory-scale capacitive deionizing (CDI) of brackish water was conducted in this study. The CDI system presented advantages of low energy demand at operation phase and low energy-related environmental impacts. With a measured electricity consumption for CDI operation at 1.44 MJ (0.4 kWh), the total cumulative energy demand for CDI system was estimated at approximately 23.9 MJ for production of 1 m(3) of desalinated water. Results from the impact assessment indicated a global warming potential (GMP100) at 1.43 kg CO2 eq, which was mainly attributed to the major reduction in electricity consumption as compared to conventional desalination technologies. Moreover, material utilization and chemical use were shown to be most responsible for overall environmental impacts in the CDI system, particularly for the use of N,N-dimethylacetamide (solvent) and titanium (material for current collector). Use of such chemicals might produce derivatives that contributed to major impacts in ozone depletion and acidification potentials. This suggests that additional efforts in future studies of CDI system may be made to substitute or reduce the two to enhance overall environmental performance of the system. (C) 2016 Elsevier B.V. All rights reserved.