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Effects of hydrologic conditions on biogeochemical processes and organic pollutant degradation in salt marsh sediments

Informally Refereed

Abstract

This work addressed the influence of tidal vs. static hydrologic conditions on biogeochemical processes and the transformation of pollutant organic chemicals (eight representative N-, O-, and S-heterocycles (NOSHs) from coal chemicals, crude oils, and pyrogenic mixtures) in salt marsh sediments. The goals were to: (1) determine the effects of static (flooded, drained) vs. dynamic (tidal) hydrology on redox potential (Eh) dynamics, trace gas evolution, and pollutant transformation; (2) deploy hydrodynamic microcosms for this purpose that were reproducible, well controlled, and adequately monitored; and, (3) develop analytical approaches for target pollutant chemicals that allowed for detection of small but significant concentration differences between time points and treatments, i.e., isotopic dilution. NOSH-amended sediments were exposed to three hydrologic conditions: static drained (oxidized redox potentials), static flooded (reduced redox potentials), and diurnal-tidal (alternating redox potential). The rate of NOSH transformation and the number of NOSHs degraded decreased in the following order: drained = tidal flooded. This indicated that sediments and associated biota exposed to tidal pulsing removed more NOSH compounds faster and to lower levels than flooded, highly reducing sediments.

Parent Publication

Citation

Catallo, W. James. 2000. Effects of hydrologic conditions on biogeochemical processes and organic pollutant degradation in salt marsh sediments. In: Proceedings of a Conference on Sustainability of Wetlands and Water Resources, May 23-25, Oxford, Mississippi, eds. Holland, Marjorie M.; Warren, Melvin L.; Stanturf, John A., p. 30-38
https://www.fs.usda.gov/research/treesearch/20140