Water Resources Research Act Program

Details for Project ID 2010ME201B

Estimation of benthic dissolved organic carbon flux from wetland sediments using a novel technique

Institute: Maine
Year Established: 2010 Start Date: 2010-03-01 End Date: 2011-02-28
Total Federal Funds: $5,039 Total Non-Federal Funds: $62,570

Principal Investigators: Aria Amirbahman, Emmanuel Boss

Abstract: Due to their high plant productivity and microbial activity, wetland sediments release significant amounts of dissolved organic carbon (DOC). DOC has a strong affinity for most toxic trace metals and leads to the formation of toxic disinfection byproducts in water treatment operation, and as such, its release from wetland sediments is of major concern. It is, therefore, desirable to have a simple and reliable technique to measure the in situ benthic DOC flux from wetland sediments. This proposed study is to develop an eddy-correlation technique – a technique well established for other systems – to compare benthic fluxes of DOC among several wetlands in central Maine. The proposed work involves 1) the deployment of autonomous acoustic and optical sensors to measure fluxes of DOC using the eddy-correlation technique, and 2) independent laboratory and field validation of the flux estimated by this technique. Laboratory validation is conducted by setting up an intact sediment column with overlying water, where turbulent eddies are induced and DOC flux is directly measured and compared with the results using the eddy-correlation technique. Field validation is conducted using high-resolution multi-chambered equilibrium samplers (peepers), and when applicable, Teflon tubes inserted into the sediment at different depths close to the sediment-water interface for determination of instantaneous high resolution pore-water concentrations at a variety of locations. The results from this study would be of interest to researches in academia and public agencies who are interested in fast and accurate measurements of benthic DOC release.