Wetlands play an important role in the environment in filtering and storing water, in the cycling of many important nutrients, and as habitats for many species. The potential for treatment wetlands to improve water quality is largely due to microbially mediated biofilm processes including nitrification, denitrification and sulfate. While the species of microbes responsible for these contaminant transformations have been identified and cultured, the performance of the biofilm community as a whole is still a topic of needed research. By quantifying rates of chemical transformation under variable environmental conditions and the rate of community adaptation (measured as the rate of change in chemical transformation rate), empirical correlations can be derived that can be used for treatment wetland modelling and design.
A novel method will be used to measure the rates of contaminant transformation for a specific biofilm area. Biofilms will be first cultivated on glass slides in natural wetlands that are then transferred to a continuously stirred tank reactor. The effluent from this reactor is analyzed for the contaminants of concern and when the rate of removal from the reactor becomes steady, the slides are again transferred to another reactor with different environmental conditions. The rate of removal is then monitored in this new reactor until steady state is again reached. The water quality parameters that will be analyzed will be pH, dissolved oxygen, oxidation-reduction potential, nitrate, phosphate, ammonia, sulfate and total organic carbon.
Student Contact: Brian Peacock, peacockb@lafayette.edu
Advisor: Prof Kney