scholarly journals Resilience of photosynthetic biomat within a unit process open water wetland following extreme events

2020 ◽  
Author(s):  
Adam Brady ◽  
Carly Oliver ◽  
Michael Vega ◽  
Jonathan Sharp ◽  
Julia Siegmund ◽  
...  
Keyword(s):  
Extreme Events ◽  
Open Water ◽  
Unit Process

scholarly journals Sunlight Inactivation of Viruses in Open-Water Unit Process Treatment Wetlands: Modeling Endogenous and Exogenous Inactivation Rates

2015 ◽  
Vol 49 (5) ◽  
pp. 2757-2766 ◽  
Author(s):  
Andrea I. Silverman ◽  
Mi T. Nguyen ◽  
Iris E. Schilling ◽  
Jannis Wenk ◽  
Kara L. Nelson
Keyword(s):  
Open Water ◽  
Treatment Wetlands ◽  
Unit Process

scholarly journals Dimensionless formulation for human stability in open flows

RBRH ◽  
2016 ◽  
Vol 21 (4) ◽  
pp. 666-673 ◽  
Author(s):  
André Luiz Andrade Simões ◽  
Harry Edmar Schulz ◽  
Lafayette Dantas da Luz
Keyword(s):  
Human Body ◽  
Extreme Events ◽  
Calculated Data ◽  
Correlation Coefficients ◽  
Open Water ◽  
Dam Breaks ◽  
Dimensionless Groups ◽  
The Stability ◽  
Dimensionless Formulation ◽  
Good Agreement

ABSTRACT The stability of humans partially immersed in risky open water flows, resulting from urban flooding caused for example by dam breaks, or failures in drainage systems, or natural extreme events, is a topic of increasing interest because it involves the human safety in an environment that is more and more subjected to extreme events of hydraulic nature. The studies in this field of the applied fluid mechanics generally present equations that handle the results through dimensional quantities. These results were generally obtained in specific experiments for the evaluation of the stability of models of the human body. Intending to advance in the direction of a more general formulation, a dimensional analysis for the problem of human stability in open flows is presented here, showing dimensionless groups that represent the mentioned problem. Equations using these nondimensional groups were then developed using statistical analyses and approximations based on principles of physics and on data of the human body. The results obtained with the proposed methodology are of very good quality, presenting high correlation coefficients and good agreement between measured and calculated data.

Nitrate removal from reverse osmosis concentrate in pilot-scale open-water unit process wetlands

2021 ◽  
Author(s):  
Rachel C. Scholes ◽  
Michael A. Vega ◽  
Jonathan O. Sharp ◽  
David L. Sedlak
Keyword(s):  
Reverse Osmosis ◽  
Nitrate Removal ◽  
Open Water ◽  
Pilot Scale ◽  
Treatment Technology ◽  
Unit Process ◽  
Novel Treatment ◽  
System P ◽  
Nitrate Concentrations

Open-water wetlands are a novel treatment technology for reverse osmosis concentrate that reduced nitrate concentrations in a pilot-scale system.

scholarly journals Biomat Resilience to Desiccation and Flooding Within a Shallow, Unit Process Open Water Engineered Wetland

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 815
Author(s):  
Adam R. Brady ◽  
Michael A. Vega ◽  
Kimberly N. Riddle ◽  
Henry F. Peel ◽  
Evelyn J. Lundeen ◽  
...  
Keyword(s):  
Water Treatment ◽  
Photosynthetic Activity ◽  
Negative Impact ◽  
Nitrate Removal ◽  
Open Water ◽  
Aquifer Recharge ◽  
Unit Process ◽  
Natural Treatment ◽  
System Resilience ◽  
The Impact

Projections of increased hydrological extremes due to climate change heighten the need to understand and improve the resilience of our water infrastructure. While constructed natural treatment analogs, such as raingardens, wetlands, and aquifer recharge, hold intuitive promise for variable flows, the impacts of disruption on water treatment processes and outcomes are not well understood and limit widespread adoption. To this end, we studied the impact of desiccation and flooding extremes on demonstration-scale shallow, unit process open water (UPOW) wetlands designed for water treatment. System resilience was evaluated as a function of physical characteristics, nitrate removal, photosynthetic activity, and microbial ecology. Rehydrated biomat that had been naturally desiccated re-established nitrate removal consistent with undisrupted biomat in less than a week; however, a pulse of organic carbon and nitrogen accompanied the initial rehydration phase. Conversely, sediment intrusion due to flooding had a negative impact on the biomat’s photosynthetic activity and decreased nitrate attenuation rates by nearly 50%. Based upon past mechanistic inferences, attenuation potential for trace organics is anticipated to follow similar trends as nitrate removal. While the microbial community was significantly altered in both extremes, our results collectively suggest that UPOW wetlands have potential for seasonal or intermittent use due to their promise of rapid re-establishment after rehydration. Flooding extremes and associated sediment intrusion provide a greater barrier to system resilience indicating a need for proactive designs to prevent this outcome; however, residual treatment potential after disruption could provide operators with time to triage and manage the system should a flood occur again.

Establishment and convergence of photosynthetic microbial biomats in shallow unit process open-water wetlands

2018 ◽  
Vol 133 ◽  
pp. 132-141 ◽  
Author(s):  
Zackary L. Jones ◽  
Kristin M. Mikkelson ◽  
Scott Nygren ◽  
David L. Sedlak ◽  
Jonathan O. Sharp
Keyword(s):  
Open Water ◽  
Unit Process

Biotransformation of Trace Organic Contaminants in Open-Water Unit Process Treatment Wetlands

2014 ◽  
Vol 48 (9) ◽  
pp. 5136-5144 ◽  
Author(s):  
Justin T. Jasper ◽  
Zackary L. Jones ◽  
Jonathan O. Sharp ◽  
David L. Sedlak
Keyword(s):  
Organic Contaminants ◽  
Open Water ◽  
Treatment Wetlands ◽  
Trace Organic Contaminants ◽  
Unit Process ◽  
Trace Organic

scholarly journals Sulfide-Induced Dissimilatory Nitrate Reduction to Ammonium Supports Anaerobic Ammonium Oxidation (Anammox) in an Open-Water Unit Process Wetland

2017 ◽  
Vol 83 (15) ◽  
Author(s):  
Zackary L. Jones ◽  
Justin T. Jasper ◽  
David L. Sedlak ◽  
Jonathan O. Sharp
Keyword(s):  
Nitrate Reduction ◽  
Municipal Wastewater ◽  
Open Water ◽  
Fold Increase ◽  
Rrna Gene ◽  
Ammonium Oxidation ◽  
Content Type ◽  
Unit Process ◽  
Dissimilatory Nitrate Reduction ◽  
Pcr Targeting

ABSTRACT Open-water unit process wetlands host a benthic diatomaceous and bacterial assemblage capable of nitrate removal from treated municipal wastewater with unexpected contributions from anammox processes. In exploring mechanistic drivers of anammox, 16S rRNA gene sequencing profiles of the biomat revealed significant microbial community shifts along the flow path and with depth. Notably, there was an increasing abundance of sulfate reducers (Desulfococcus and other Deltaproteobacteria) and anammox microorganisms (Brocadiaceae) with depth. Pore water profiles demonstrated that nitrate and sulfate concentrations exhibited a commensurate decrease with biomat depth accompanied by the accumulation of ammonium. Quantitative PCR targeting the anammox hydrazine synthase gene, hzsA, revealed a 3-fold increase in abundance with biomat depth as well as a 2-fold increase in the sulfate reductase gene, dsrA. These microbial and geochemical trends were most pronounced in proximity to the influent region of the wetland where the biomat was thickest and influent nitrate concentrations were highest. While direct genetic queries for dissimilatory nitrate reduction to ammonium (DNRA) microorganisms proved unsuccessful, an increasing depth-dependent dominance of Gammaproteobacteria and diatoms that have previously been functionally linked to DNRA was observed. To further explore this potential, a series of microcosms containing field-derived biomat material confirmed the ability of the community to produce sulfide and reduce nitrate; however, significant ammonium production was observed only in the presence of hydrogen sulfide. Collectively, these results suggest that biogenic sulfide induces DNRA, which in turn can explain the requisite coproduction of ammonium and nitrite from nitrified effluent necessary to sustain the anammox community. IMPORTANCE This study aims to increase understanding of why and how anammox is occurring in an engineered wetland with limited exogenous contributions of ammonium and nitrite. In doing so, the study has implications for how geochemical parameters could potentially be leveraged to impact nutrient cycling and attenuation during the operation of treatment wetlands. The work also contributes to ongoing discussions about biogeochemical signatures surrounding anammox processes and enhances our understanding of the contributions of anammox processes in freshwater environments.

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