SUSTAINABLE PRODUCTION OF BIODEGRADABLE THERMOPLASTICS THROUGH WASTEWATER TREATMENT, AND A NEW THEORY ON BIOLOGICAL PHOSPHORUS REMOVAL By ERIK ROBERT COATS A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY

By Erik Robert Coats, Ph.D. Washington State University December 2005 Chairs: Michael P. Wolcott, Frank J. Loge Biologically-derived polyesters known as polyhydroxyalkanoates (PHAs) represent a potentially sustainable replacement to fossil fuel-based thermoplastics. However, current production practices do not achieve this objective. Herein we report on the production of PHA with a mixed microbial consortium indigenous to a wastewater treatment process on carbon present in wastewaters in a unit-operation configuration congruent with wastewater treatment. PHA production averaged 85, 10, and 53% (w/w) on pulp-and-paper mill foul condensate, biodiesel, and municipal wastewaters, respectively. Given the proposed polymer production process eliminates the energy and costs associated with feedstock production and bioreactor operation (two of the three major energy and cost sinks), and further that wastewater treatment is mandated in most countries, results presented suggest environmentally benign (e.g., sustainable) PHA production is feasible. As a further enhancement, PHA-rich microbial cell mass was utilized to produce a natural fiber reinforced thermoplastic composite (NFRTC). Specifically, polyhydroxybutyrate-rich biomass was synthesized with the mutant Azotobacter vinelandii UWD and utilized in unpurified form to manufacture NFRTCs with wood flour. Resulting