9316745 Chin Wetlands are a natural resource of paramount importance in that they are highly productive and biodiverse, and provide shelter for a number of endangered species. This unique environment can also be "engineered" to treat aquatic pollutants. Synthetic organic compounds (SOCs) from agricultural run-off, atmospheric deposition, and other nonpoint sources threaten their ecology. One aspect of SOC fate and transport in a wetland ecosystem that is poorly understood is the role of mobile organic colloids that can bind many nonpopular organic substances and enhance some aqueous phase concentrations well beyond equilibrium expectations. The proposed study of the effects of organic colloids on the speciation and mobility of SOCs in wetland environments will (1) measure the in situ distribution of SOCs between environmental compartments, (2) determine the abundances and distribution of organic colloids in wetlands, (3) characterize the physiochemical properties of organic colloids, (4) determine the partition reactivity of wetland organic colloids to SOCs, and (5) correlate the properties of organic colloids with their propensity to react with SOCs. Samples will be collected from three sites in Ohio: Old Woman's Creek, Cedar Bog, and the proposed Olentangy River constructed wetlands in Columbus. The proposed research will better our understanding of and improve our ability to model the role of colloids in controlling the fate and transport of organic pollutants in wetlands and aquatic systems. The information accrued from this project should aid those individuals responsible for managing ecosystems, and help engineers properly design and construct wetlands for purposes of remediating nonpoint source pollutants.