Thomas A. DeBusk

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Submerged aquatic vegetation (SAV) communities exhibit phosphorus (P) removal mechanisms not found in wetlands dominated by emergent macrophytes. This includes direct assimilation of water column P by the plants and pH-mediated P coprecipitation with calcium carbonate (CaCO3). Recognizing that SAV might be employed to increase the performance of treatment(More)
Rhodamine-WT and LiCl were compared for their suitability as hydraulic tracers in wetlands. Using outdoor mesocosms, we found lithium to be more conservative than rhodamine-WT when initial concentrations were 4.9 to 64 μg/L for rhodamine-WT and 28–516 μg/L for Li+ (1∶6 to 1∶8 (wt/wt) ratio of rhodamine-WT to Li+). At higher initial concentrations (i.e., 100(More)
The 1994 Everglades Forever Act mandates the South Florida Water Management District and the Florida Department of Environmental Protection to evaluate a series of advanced treatment technologies to reduce total phosphorus (TP) in Everglades Agricultural Area runoff to a threshold target level. A submerged aquatic vegetation/limerock (SAV/LR) treatment(More)
In situ rates of waterhyacinth decomposition were found to vary with tissue nitrogen and fiber content. High nitrogen (2.8%), low fiber (49%) waterhyacinth aerial tissues collected from a eutrophic site decomposed more rapidly than low nitrogen (1.3%), high fiber (58%) aerial tissues collected from a nutrient-poor site. In addition, waterhyacinth roots (65%(More)
Soluble reactive phosphorus (SRP) concentrations in wetland surface waters were measured during laboratory incubations in the presence of wetland soils and Typha leaf litter. Aerated water columns above intact soil cores increased in SRP concentration (up to 73 μg L−1) over 28 days, whereas the water column in cores containing soil and a Typha litter layer(More)
Large constructed wetlands, known as stormwater treatment areas (STAs), have been deployed to remove phosphorus (P) in drainage waters before discharge into the Everglades in South Florida, USA. Their P removal performance depends on internal P cycling under typically hydrated, but with occasionally desiccated, conditions. We examined the spatial and(More)
Nutrient-enriched water hyacinths were stocked in outdoor tanks and cultured under both high nutrient (HN) and low nutrient (LN) regimes for 10 months. Seasonal changes in standing crop biomass and morphology of LN water hyacinths were similar to those of HN water hyacinths, despite a ten-fold between-treatment difference in N availability and a two-fold(More)
Gradients in phosphorus (P) removal and storage were investigated over 6 years using mesocosms (each consisting of three tanks in series) containing submerged aquatic vegetation (SAV) grown on muck and limerock (LR) substrates. Mean inflow total P concentrations (TP) of 32 μg L(-1) were reduced to 15 and 17 μg L(-1) in the muck and LR mesocosms,(More)
The recent implementation of agricultural best management practices (BMPs) and treatment wetlands called stormwater treatment areas (STAs) have reduced phosphorus (P) concentrations and loadings to the Everglades Protection Area (EPA) in Florida (USA). There is a concern that despite reductions in external P loadings, internal loading from the legacy P(More)
Phosphorus (P) removal from wastewaters and surface runoff using macrophyte-based systems (MBS) has been a topic of great interest in Florida for over 25 years. During this period, P removal by both treatment wetlands and floating aquatic macrophyte systems has been evaluated from both a research and operational standpoint. Several factors have contributed(More)
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