Ms. Huan-Yu Shiu
National Taiwan University
MS. Huan-Yu Shiu is a Ph. D. Candidate in Environmental Engineering at National Taiwan University. She is interested in environmental evaluation analysis and environmental management. Life cycle assessment (LCA) method is one of her specialty. Her research focuses on developing LCA method with time factor by using system dynamics thinking. The issue of water treatment and water recycling are focused on her research. Shiu assisted two projects from the government department. Shiu evaluated the environmental performers of capacitive deionization (CDI) in the project of water resources agency. The ultimate goal for the CDI’s advancement is high performance and low environmental impact for ensuring sustainable water supplies. The other project in the ministry of science and technology, Shiu evaluate the water quality improvement technologies by LCA and suggest the management of the urban water supply. Now her working interest is the development of dynamic LCA to make environmental assessment more detailed.Hotspots analysis and improvement schemes for capacitive deionization (CDI) using life cycle assessment
The ultimate goal for the CDI’s advancement is high performance and low environmental impact for ensuring sustainable water supplies. The aim of this study was to have comprehensive knowledge on the improvements of CDIs from environmental aspect. Life cycle assessment (LCA) was utilized to evaluate the environmentally friendliness of the CDIs. Five lab-scale design schemes, including original and basic CDI, membrane capacitive deionization (MCDI) and scale-up MCDI stacks, were being investigated in this study. A technical performance indicator of productivity (L/h/m2) was also employed to elucidate the efficiency of water production of the CDIs. LCA results of the CDI stacks indicated that electricity consumption had a relatively lower overall impact (as low as 9.7%) compared to material or chemical usages (ranges from 52 to 89.8%), and little contribution from discharge of concentrate and wastes (<1%). This suggested that changing of key materials or chemicals in improved stacks could decrease their associated impacts. Our results further advised the importance of the management of chemical use of N-Methyl-2-pyrrolidone (NMP), the substitute for DMAC in the basic CDI stack. The scale-up MCDI stacks exhibited the highest productivity of 3.62 L/h/m2, indicating that CDI poses the potential to be an efficient water technology. LCA was demonstrated to support future improvement decisions for CDI with favorable environmental performance.