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A new framework for approaching precision bioremediation of PAH contaminated soils
Title
A new framework for approaching precision bioremediation of PAH contaminated soils.
Creator
Redfern, Lauren, Gardner, Courtney M., Hodzic, Emina, Ferguson, P. Lee, Hsu-Kim, Helen, Gunsch, Claudia K.
Abstract / Description
Bioremediation is a sustainable treatment strategy which remains challenging to implement especially in heterogeneous environments such as soil and sediment. Herein, we present a novel precision bioremediation framework that integrates amplicon based metagenomic analysis and chemical profiling. We applied this approach to samples obtained at a site contaminated with polycyclic aromatic hydrocarbons (PAHs). Geobacter spp. were identified as biostimulation targets because they were one of the...
Show moreBioremediation is a sustainable treatment strategy which remains challenging to implement especially in heterogeneous environments such as soil and sediment. Herein, we present a novel precision bioremediation framework that integrates amplicon based metagenomic analysis and chemical profiling. We applied this approach to samples obtained at a site contaminated with polycyclic aromatic hydrocarbons (PAHs). Geobacter spp. were identified as biostimulation targets because they were one of the most abundant genera and previously identified to carry relevant degradative genes. Mycobacterium and Sphingomonads spp. were identified as bioaugmentation and genetic bioaugmentation targets, respectively, due to their positive associations with PAHs and their high abundance and species diversity at all sampling locations. Overall, this case study suggests this framework can help identify bacterial targets for precision bioremediation. However, it is imperative that we continue to build our databases as the power of metagenomic based approaches remains limited to microorganisms currently in our databases.
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Date Issued
2019-10-01
Identifier
fgcu_ir_001018
Format
Citation
Transitioning from gray to green (G2G)—A green infrastructure planning tool for the urban forest
Title
Transitioning from gray to green (G2G)—A green infrastructure planning tool for the urban forest.
Creator
Tsegaye, Seneshaw, Singleton, Thomas L., Koeser, Andrew K., Lamb, David S., Landry, Shawn M., Ku, Shen, Barber, Joshua B., Hilbert, Deborah R., Hamilton, Keir O., Northrop,...
Show moreTsegaye, Seneshaw, Singleton, Thomas L., Koeser, Andrew K., Lamb, David S., Landry, Shawn M., Ku, Shen, Barber, Joshua B., Hilbert, Deborah R., Hamilton, Keir O., Northrop, Robert J., Ghebremichael, Kebreab
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Abstract / Description
Urban stormwater managers have traditionally used pipes, ditches, ponds and other gray infrastructure elements to quickly divert runoff away from its main sources—buildings and roadways. In contrast, proponents of green infrastructure attempt to manage stormwater near its origin, utilizing natural drainage pathways and best management practices (BMPs) to reduce runoff and increase infiltration. In doing so, stormwater is retained where it is needed to support urban vegetation. This vegetation...
Show moreUrban stormwater managers have traditionally used pipes, ditches, ponds and other gray infrastructure elements to quickly divert runoff away from its main sources—buildings and roadways. In contrast, proponents of green infrastructure attempt to manage stormwater near its origin, utilizing natural drainage pathways and best management practices (BMPs) to reduce runoff and increase infiltration. In doing so, stormwater is retained where it is needed to support urban vegetation. This vegetation, in turn, helps reduce future runoff, while producing a whole range of environmental, economic, and social/human health-related benefits. Despite the many advantages of green infrastructure, retrofitting the infrastructure of a city is a costly process that requires careful planning. The transition from gray to green infrastructure requires communication between managers from different disciplines and a willingness to stray from management strategies that have defined stormwater management for centuries. The Gray to Green (G2G) green infrastructure planning tool is designed to facilitate these conversations—showing both technical and non-technical users how green infrastructure BMPs can work within the urban forest to manage stormwater on existing or proposed development sites. This paper details the data sources and research at the core of G2G—documenting all methods, equations, and assumptions used in its creation to provide users with a fully-transparent and peer-reviewed planning tool. The paper concludes with descriptions and user insights from two case studies from Tampa, Florida (United States) and Milwaukee, Wisconsin, (United States).
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Date Issued
2019-04-01
Identifier
fgcu_ir_001017
Format
Citation
A new approach for using GIS to link infiltration BMPs to Groundwater Pollution Risk
Title
A new approach for using GIS to link infiltration BMPs to Groundwater Pollution Risk.
Creator
Tsegaye, Seneshaw, Gallagher, Kristopher C., Alsharif, Kamal, Van Beynen, Philip
Abstract / Description
This research analyzed the efficiency of the BMP Siting Tool developed by the US Environmental Protection Agency and the Grey-to-Green Decision Support Tool. Both tools were used in conjunction with ArcGIS 10.1 to obtain cartographic data illustrating suitable sites for bioswales and infiltration basins in Hillsborough County, Florida. The data were integrated with the Karst Aquifer Vulnerability Index (KAVI) groundwater vulnerability model. The BMP Siting Tool sited 2.80% of all bioswales...
Show moreThis research analyzed the efficiency of the BMP Siting Tool developed by the US Environmental Protection Agency and the Grey-to-Green Decision Support Tool. Both tools were used in conjunction with ArcGIS 10.1 to obtain cartographic data illustrating suitable sites for bioswales and infiltration basins in Hillsborough County, Florida. The data were integrated with the Karst Aquifer Vulnerability Index (KAVI) groundwater vulnerability model. The BMP Siting Tool sited 2.80% of all bioswales and 27.89% of all infiltration basins above vulnerable areas identified by the KAVI. Alternatively, 21.66% of all bioswales and 9.62% of all infiltration basins sited by the Grey-to-Green Decision Support Tool were above vulnerable areas. The results of this analysis prompted the proposal of a supplemental framework unique to each tool’s weakness. The idea behind the supplemental framework is to determine the most suitable sites for stormwater BMPs by refining the current siting framework to better respect groundwater integrity.
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Date Issued
2019-02-18
Identifier
fgcu_ir_001016
Format
Citation
Impacts of coal ash on methylmercury production and the methylating microbial community in anaerobic sediment slurries
Title
Impacts of coal ash on methylmercury production and the methylating microbial community in anaerobic sediment slurries.
Creator
Redfern, Lauren, Schwartz, Grace E., Ikuma, Kaoru, Gunsch, Claudia K., Ruhl, Laura S., Vengosh, Avner, Hsu-Kim, Heileen
Abstract / Description
Mercury (Hg) associated with coal ash is an environmental concern, particularly if the release of coal ash to the environment is associated with the conversion of inorganic Hg to methylmercury (MeHg), a bioaccumulative form of Hg that is produced by anaerobic microorganisms. In this study, sediment slurry microcosm experiments were performed to understand how spilled coal ash might influence MeHg production in anaerobic sediments of an aquatic ecosystem. Two coal ash types were used: (1) a...
Show moreMercury (Hg) associated with coal ash is an environmental concern, particularly if the release of coal ash to the environment is associated with the conversion of inorganic Hg to methylmercury (MeHg), a bioaccumulative form of Hg that is produced by anaerobic microorganisms. In this study, sediment slurry microcosm experiments were performed to understand how spilled coal ash might influence MeHg production in anaerobic sediments of an aquatic ecosystem. Two coal ash types were used: (1) a weathered coal ash; and (2) a freshly collected, unweathered fly ash that was relatively enriched in sulfate and Hg compared to the weathered ash. These ash samples were added to anaerobic sediment slurries constructed with a relatively pristine sediment (containing 0.03 mg kg−1 Hg) and a Hg-contaminated sediment (containing 0.29 mg kg−1 Hg). The results of these experiments showed negligible net production of MeHg in microcosms with no ash and in microcosms amended with the low sulfate/low Hg ash. In contrast, slurry microcosms amended with high sulfate/high Hg ash showed increases in total MeHg content that was 2 to 3 times greater than control microcosms without ash (p < 0.001). 16S amplicon sequencing of microbial communities in the slurries indicated that the coal ash addition generally increased the relative abundance of the methylating microbial community, including sulfate-reducing bacteria and iron-reducing bacteria species that are known to be efficient methylators of Hg. The stimulation of these microorganisms was likely caused by the release of substrates (sulfate and Fe) originating from the ash. Overall, the results highlight the need to incorporate both environmental parameters and coal ash characteristics into risk assessments that guide coal ash management and disposal.
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Date Issued
2016-09-01
Identifier
fgcu_ir_001021
Format
Citation
A Clustered, Decentralized Approach to Urban Water Management
Title
A Clustered, Decentralized Approach to Urban Water Management.
Creator
Tsegaye, Seneshaw, Missimer, Thomas, Kim, Jong-Yeop, Hock, Jason
Abstract / Description
Current models in design of urban water management systems and their corresponding infrastructure using centralized designs have commonly failed from the perspective of cost effectiveness and inability to adapt to the future changes. These challenges are driving cities towards using decentralized systems. While there is great consensus on the benefits of decentralization; currently no methods exist which guide decision-makers to define the optimal boundaries of decentralized water systems. A...
Show moreCurrent models in design of urban water management systems and their corresponding infrastructure using centralized designs have commonly failed from the perspective of cost effectiveness and inability to adapt to the future changes. These challenges are driving cities towards using decentralized systems. While there is great consensus on the benefits of decentralization; currently no methods exist which guide decision-makers to define the optimal boundaries of decentralized water systems. A new clustering methodology and tool to decentralize water supply systems (WSS) into small and adaptable units is presented. The tool includes two major components: (i) minimization of the distance from source to consumer by assigning demand to the closest water source, and (ii) maximization of the intra-cluster homogeneity by defining the cluster boundaries such that the variation in population density, land use, socio-economic level, and topography within the cluster is minimized. The methodology and tool were applied to Arua Town in Uganda. Four random cluster scenarios and a centralized system were created and compared with the optimal clustered WSS. It was observed that the operational cost of the four cluster scenarios is up to 13.9 % higher than the optimal, and the centralized system is 26.6% higher than the optimal clustered WSS, consequently verifying the efficacy of the proposed method to determine an optimal cluster boundary for WSS. In addition, optimal homogeneous clusters improve efficiency by encouraging reuse of wastewater and stormwater within a cluster and by minimizing leakage through reduced pressure variations.
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Date Issued
2020-01-09
Identifier
fgcu_ir_001015
Format
Document (PDF)
Investigating the mycobiome of the Holcomb Creosote Superfund Site
Title
Investigating the mycobiome of the Holcomb Creosote Superfund Site.
Creator
Redfern, Lauren, Czaplicki, Lauren M., Cooper, Ellen M., Ferguson, P. Lee, Vilgalys, Rytas, Gunsch, Claudia K.
Abstract / Description
Even though many fungi are known to degrade a range of organic chemicals and may be advantageous for targeting hydrophobic chemicals with low bioavailability due to their ability to secrete extracellular enzymes, fungi are not commonly leveraged in the context of bioremediation. Here we sought to examine the fungal microbiome (mycobiome) at a model creosote polluted site to determine if fungi were prevalent under high PAH contamination conditions as well as to identify potential...
Show moreEven though many fungi are known to degrade a range of organic chemicals and may be advantageous for targeting hydrophobic chemicals with low bioavailability due to their ability to secrete extracellular enzymes, fungi are not commonly leveraged in the context of bioremediation. Here we sought to examine the fungal microbiome (mycobiome) at a model creosote polluted site to determine if fungi were prevalent under high PAH contamination conditions as well as to identify potential mycostimulation targets. Several significant positive associations were detected between OTUs and mid-to high-molecular weight PAHs. Several OTUs were closely related to taxa that have previously been identified in culture-based studies as PAH degraders. In particular, members belonging to the Ascomycota phylum were the most diverse at higher PAH concentrations suggesting this phylum may be promising biostimulation targets. There were nearly three times more positive correlations as compared to negative correlations, suggesting that creosote-tolerance is more common than creosote-sensitivity in the fungal community. Future work including shotgun metagenomic analysis would help confirm the presence of specific degradation genes. Overall this study suggests that mycobiome and bacterial microbiome analyses should be performed in parallel to devise the most optimal in situ biostimulation treatment strategies.
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Date Issued
2020-08-01
Identifier
fgcu_ir_001019
Format
Citation
Acetate promotes microbial reductive debromination of tetrabromobisphenol A during the startup phase of anaerobic wastewater sludge bioreactors
Title
Acetate promotes microbial reductive debromination of tetrabromobisphenol A during the startup phase of anaerobic wastewater sludge bioreactors.
Creator
Redfern, Lauren, Lefevre, Emilie, Cooper, Ellen M., Stapleton, Heather M., Gunsch, Claudia K.
Abstract / Description
The detection of increasing concentrations of tetrabromobisphenol A (TBBPA) in wastewater treatment plants is raising concerns as TBBPA has been identified as a potentially toxic flame retardant. The objectives of this study were to evaluate the effect of acetate biostimulation on TBBPA microbial reductive debromination, and the response of anaerobic sludge associated microbial communities repeatedly exposed to TBBPA. Results indicate that the bulk of the microbial community did not...
Show moreThe detection of increasing concentrations of tetrabromobisphenol A (TBBPA) in wastewater treatment plants is raising concerns as TBBPA has been identified as a potentially toxic flame retardant. The objectives of this study were to evaluate the effect of acetate biostimulation on TBBPA microbial reductive debromination, and the response of anaerobic sludge associated microbial communities repeatedly exposed to TBBPA. Results indicate that the bulk of the microbial community did not experience significant shifts as a result of TBBPA exposure, and that only a small fraction of the community responded to the presence of TBBPA. Taxa most likely responsible for TBBPA transformation affiliated to Clostridiales and the wastewater sludge group Blvii28. The biostimulating effect of acetate was only observed during reactor startup, when acetogenesis was likely not yet occurring. However, when acetate likely started to be microbially generated in the reactor, acetate addition resulted in a slight but significant inhibiting effect on TBBPA transformation. A significant increase of hydrogenotrophic methanogens in the TBBPA-spiked reactor overtime implies that TBBPA degraders were not in direct competition with methanogens for H2. These results strongly suggest that TBBPA degrading taxa might have been primarily using acetate as an electron donor for the reductive debromination of TBBPA.
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Date Issued
2019-03-01
Identifier
fgcu_ir_001020
Format
Citation