Assessing environmental sustainability using FLAG: A case study of a novel semiconductor material critical to emerging energy technologies

点击翻译按钮获取中文摘要

0853866HemondIndium, an important metal, will be assessed by implementing an approach termed FLAG (Framework for Life-Cycle Assessment Using Geochemistry). The FLAG approach expands on Life Cycle Assessment (LCA) by assessing industrial life cycles in the context of geochemical cycles. Features of FLAG are: 1) comparison of anthropogenic and natural fluxes; 2) explicit study of global, regional, and local scales; 3) characterization of physical and chemical forms; and 4) recognition of a distinction between primarily mined metals and metals that are byproducts. FLAG is proposed for use in product development as an 'early warning system' that will allow potentially harmful elements to be flagged for priority study when projected anthropogenic fluxes rival or exceed natural fluxes. Indium, which is of particular importance in new families of high efficiency photovoltaic devices, light-emitting diodes (LEDs), and indium tin oxide (ITO) electrical coatings, has been selected for study because its environmental cycling is poorly understood, toxicity has been suggested, and its industrial use is poised for exponential expansion. Natural and industrial fluxes of indium will be determined at the global, regional, and local scales. Education and outreach components of the project include: 1) involvement of graduate and undergraduate students in the research; 2) creation of a metal cycling exhibit for the Cambridge, MA annual science festival and a five-session science unit for 6th-8th graders in the Summerbridge Cambridge after-school program; and 3) collaboration with individuals in the mining and semiconductor industries.