A stochastic approach to designing wetlands for stormwater pollution control

Wong, Tony Hoong Fatt; Somes, Nick L

doi:10.1016/0273-1223(95)00549-3

Cited by 16 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The construction of stormwater wetlands is widely recognized as an effective measure to abate stormwater runoff and reduce the environmental impacts of urbanization . Stormwater wetlands serve several purposes, including sedimentation, chemical adsorption, and biological filtration (by vegetation and bacteria), while also providing habitat and environmental value to urban environments . By design, stormwater wetlands accumulate sediment and associated contaminants, protecting downstream receiving waters but potentially harming biota that live in them.…”

Section: Introductionmentioning

confidence: 99%

Bifenthrin Causes Toxicity in Urban Stormwater Wetlands: Field and Laboratory Assessment Using Austrochiltonia (Amphipoda)

Jeppe

Kellar

Marshall

et al. 2017

Environ. Sci. Technol.

View full text Add to dashboard Cite

Stormwater wetlands are engineered to accumulate sediment and pollutants from stormwater and provide environmental value to urban environments. Therefore, contaminated sediment risks causing toxicity to aquatic fauna. This research identifies contaminants of concern in urban wetland sediments by assessing sediment toxicity using the amphipod Austrochiltonia subtenuis. Sediments from 98 wetlands were analyzed for contaminants, and laboratory bioassays were performed with A. subtenuis. Wild Austrochiltonia spp. were also collected from wetlands to assess field populations. Random forest modeling was used to identify the most important variables predicting survival, growth, and field absence of Austrochiltonia spp. Bifenthrin was the most frequently detected pesticide and also the most important predictor of Austrochiltonia spp. responses. Copper, permethrin, chromium, triclosan, and lead were also important. The median lethal effect concentration (LC50) of bifenthrin to laboratory-based A. subtenuis (1.09 (±0.08) μg/gOC) exposed to wetland sediments was supported by a bifenthrin-spiked sediment experiment, indicating A. subtenuis is a suitable test species. Furthermore, Austrochiltonia spp. were absent from all sites that exceeded the calculated bifenthrin LC50, demonstrating the impact of this contaminant on wild populations. This research demonstrates the sensitivity of Austrochiltonia spp. to urban sediment contamination and identifies bifenthrin as a contaminant of concern in urban wetlands.

show abstract

Section: Introductionmentioning

confidence: 99%

Bifenthrin Causes Toxicity in Urban Stormwater Wetlands: Field and Laboratory Assessment Using Austrochiltonia (Amphipoda)

Jeppe

Kellar

Marshall

et al. 2017

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Hydrodynamic dispersion is the net result of variable advection and diffusion and can be rigorously modelled using plug flow with dispersion reactor models (Walker, 1998). Alternatively, a tanks-in-series approach can also be used and has been adopted by several researchers to characterize incomplete pollutant mixing in wetlands (Carleton, 2002;Kadlec & Wallace, 2007;Wong & Somes, 1995). This approach is intuitive and provides results comparable to a plug flow with dispersion model.…”

Section: Introductionmentioning

confidence: 99%

Modelling pollutants transport and degradation through wetlands

Imteaz

Uddameri²,

Ahsan

2013

Piantadosi, J., Anderssen, R.S. And Boland J. (Eds) MODSIM2013, 20th International Congress on Modelling and Simulation

View full text Add to dashboard Cite

Wetlands play a number of roles in the water environment, principally water purification, flood control, and groundwater replenishment. In addition to these benefits, United Nations Millennium Ecosystem Assessment and Ramsar Convention defined wetlands to be of biosphere significance and societal importance in the areas of shoreline stabilisation, storm protection, cultural values, recreation and tourism, and climate change mitigation and adaptation. Wetlands are also considered the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal life. The function of most natural wetland systems is not to treat wastewater, however, their high potential for the filtering and the treatment of pollutants has been recognized by environmental scientists who specialize in the area of wastewater treatment.In the past wetlands used to be in place naturally and used to provide ecological benefits to the mankind and environment. Through recognizing their immense benefits, human being started to construct artificial wetlands. Recently, constructed wetlands are recommended as one of the salient features of water sensitive urban design, which play an important role in water management and ecologically sustainable development. These constructed artificial wetland systems are highly controlled environments that intend to mimic the occurrences of soil, flora, and microorganisms in natural wetlands to help in treating wastewater effluent. Artificial wetlands provide the ability to experiment with flow regimes, micro-biotic composition, and flora in order to produce the most efficient treatment process.Constructed wetlands are increasingly being designed and used to treat wastewaters. Majority of constructed wetlands are designed based on steady-state releases of pollutants loading. However, in some cases (i.e. aquaculture ponds) pollutant loadings are not steady-state, rather are intermittent. Pollutants transport analysis based on steady-state release (inflow) will be quite different from an analysis based on intermittent loading/inflow. In the past several studies were conducted on pollutants transport and degradation through wetlands using steady-state inflow of pollutants. In this paper, a simple numerical model is proposed and developed based on conservation of mass principle for the pollutants and transport through a wetland, considering a series of tanks. Tank-in-series approach assumes that the wetland is comprised of several interconnected tanks, each of which can be modeled as a continuous flow stirred tank reactor. As for pollutants, in this study organic matters are considered. Same numerical model can be used for different organic matters, considering different values of degradation rate. Using first-order kinetic equations of pollutants transport and degradation and applying Euler's method of difference equations a numerical model was developed. Developed numerical model can simulate pollutant transport and degradations for steadystate, continuous and/or irregular/intermittent pollut...

show abstract

“…Hydrodynamic dispersion is the net result of variable advection and diffusion and can be rigorously modeled using plug flow with dispersion (PFD) reactor models [20]. Alternatively, a tanks-in-series approach can also be used [9] and has been adopted by several researchers (e.g., [2,14,24]) to characterize incomplete pollutant mixing in wetlands. This approach is intuitive and provides results comparable to a PFD model.…”

Section: Introductionmentioning

confidence: 99%

An Analytical Solution to Model Aquaculture Wetlands Subject to Intermittent Loading and Variable Initial Concentrations

Uddameri

2009

Environ Model Assess

View full text Add to dashboard Cite

Constructed wetlands are increasingly being used to treat intermittent releases of wastewaters from aquaculture ponds. Most constructed wetland design protocols are based on steady-state releases and as such are incapable of characterizing transient pollutant distribution arising from intermittent releases. Given the seasonal nature of aquaculture operations, the constructed wetland has to be developed using water from other nearby sources (termed as fill water in this study). In some instances, the pollutant concentrations in the fill water are noted to be greater than that measured in the aquaculture ponds. Also, the pollutants in the wetland may exhibit spatial variability due to geochemical interactions with wetland soils. These effects cannot be captured with existing steady-state design schemes. A mathematical model based on the tanks-in-series conceptualization is developed to overcome the aforementioned limitations. An analytical solution for multiple intermittent releases and spatially varying initial concentrations is obtained using Laplace transform and superposition techniques. The utility of the developed model is illustrated using an example based after a constructed wetland at the Loma Alta Shrimp Aquaculture Facility (LASAF) in South Texas. The developed model captures the extremely nonlinear relationship between the maximum discharge concentration and the hydraulic residence time. For the conditions assumed in this study, the extent of mixing is not of major concern when the spacing between the loadings is greater than 0.75 times the hydraulic residence time (HRT). Model results also suggest that the wetland should be oriented in a manner such that the internal geochemical production of the pollutant, if any, is near the inlet.

show abstract

A stochastic approach to designing wetlands for stormwater pollution control

Cited by 16 publications

References 0 publications

Bifenthrin Causes Toxicity in Urban Stormwater Wetlands: Field and Laboratory Assessment Using Austrochiltonia (Amphipoda)

Bifenthrin Causes Toxicity in Urban Stormwater Wetlands: Field and Laboratory Assessment Using Austrochiltonia (Amphipoda)

Modelling pollutants transport and degradation through wetlands

An Analytical Solution to Model Aquaculture Wetlands Subject to Intermittent Loading and Variable Initial Concentrations

Contact Info

Product

Resources

About