SusChEM: Novel biomimetic materials for water purification: perchlorate treatment

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

CBET-1336620 Julie Zilles & Charles Werth University of Illinois Urbana Champaign New technologies are needed to remove emerging contaminants such as pharmaceuticals, personal care products, and endocrine-disrupting compounds from water. While these contaminants have a wide range of sources, chemical structures, and effects, they share the properties of being toxic even at low concentrations and of being biologically recognized. This project will harness the high specificity, affinity, and activity of biological enzymes to develop novel materials, referred to as biocatalysts, to degrade the drinking water contaminant perchlorate. The enzymes will be tested in two forms: free in solution and encapsulated in hollow lipid spheres or vesicles. Encapsulation in vesicles is expected to increase stability but also to introduce diffusion limitations. The first objective is therefore to measure fundamental properties of these materials: diffusion limitations, reaction rates, and longevity. These data will identify what properties are most likely to limit the utility of the material, providing a focus for subsequent research and data for an initial assessment of the economic feasibility and environmental impacts. Other project objectives will target the limiting properties for improvement using a two-step process of mining biology and applying directed evolution. The first step, mining biology, will consist of screening existing enzyme variants from different microorganisms to identify those with the most suitable combination of properties. In the second step, directed evolution will be used to further improve the best existing enzymes. This approach involves iterative cycles of making random mutations and selecting for those mutant enzymes that show improvements in the desired property. In parallel with these objectives, the project will compare the sustainability of biocatalytic materials for perchlorate reduction to existing and emerging perchlorate treatment options. This sustainability analyses will incorporate economic and environmental impacts in life cycle analysis using both the initial properties and the improved properties obtained in later objectives. The results of the ongoing sustainability analyses will guide the development of these materials and will provide a more general assessment of the potential of biocatalytic materials for water treatment. This project will contribute to safe drinking water through the development of perchlorate treatment technologies that are effective and efficient. By incorporating evaluation of the potential economic and environmental impacts at an early stage, this research will emphasize development of sustainable water treatment processes. More generally, the insight into factors limiting activity of biocatalytic materials gained here will demonstrate the potential and limitations of this approach, which could provide a highly specific and sensitive means of dealing with emerging contaminants and facilitating water reuse. This work will also contribute to the interdisciplinary education of undergraduate and graduate students in microbiology and engineering, and promote diversity in science and engineering through middle school and high school outreach including under-represented minority students.