NTE: Innovative Technologies for Heavy Metals Removal by Tunable Biopolymers with Customized Properties (TSE03-N, PHASE II)

University Of California-Riverside, Riverside CA

Investigators

Abstract

Chen 0329482 Soil and groundwater contamination by heavy metals is prevalent at hazardous waste sites in the United States. To remediate these sites there is a strong interest in developing novel polymeric materials that have superior affinity, capacity, and selectivity for target heavy metals because of their unique physical, chemical and biological properties. Genetic and protein engineering have emerged as the latest tools for the construction of novel materials that can be controlled precisely at the molecular level. With the advent of recombinant DNA techniques, it is now possible to create "artificial" protein polymers with fundamentally new molecular organization. The most significant feature of these nanoscale biopolymers is that they are specifically pre-programmed within a synthetic gene template and can be controlled precisely in terms of sizes, compositions and functions at the molecular level. In our Phase I NTE project, a class of tunable biopolymers, which can reversibly aggregate, has been developed and were shown to have high specificity for the target heavy metals in a highly heterogeneous solution. The overall objective in Phase II is to further our investigations on the design, synthesis, and applicability of these new tunable biopolymers both in situ and ex situ removal of cadmium, lead, mercury and arsenic. A class of protein-based triblock polymers will be created and the feasibility of utilizing the resulting porous structures as affinity barriers will be investigated. Intellectual Merit: The tunable biopolymers proposed herein are extensions of ideas from nature toward entirely new objectives. Molecular-level protein-protein recognition is tailored specifically into tunable metal-binding biopolymers. These biopolymers can be easily applied for both in situ and ex situ heavy metal removal. This operation is environmentally friendly since no toxic chemical is required for synthesis of the biopolymers and regeneration can be achieved easily. This strategy, if successful, will provide a low-cost, efficient, and environmentally benign technology for heavy metal removal. Broader Impact: This proposal will combine the multidisciplinary expertise of the PIs to develop a potentially reliable and economical process for the decontamination of heavy metal contaminated groundwaters and/or soil. The integration of the development of tunable biopolymers for heavy metal removal with process development represents a unique effort that expands the fundamental development of protein engineering with the implementation of process technology. The proposed research involves intersection of principles and methods of molecular genetics, protein engineering, material research, and process engineering. Graduate students and postdoctoral researchers participating in this research will gain an integrated perspective of the important interfaces and synergies connecting biochemistry, modern genetics, and process engineering. As the integration of research and education is one of the key programs of NSF, the proposed research will involve the participation of K-12 school students, undergraduates and graduate students, particularly form underrepresented groups.