Calibration of three resuspension/sedimentation models

Blom, G.; Aalderink, R.H.

doi:10.2166/wst.1998.0171

Cited by 12 publications

(14 citation statements)

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“…The residence time of contaminants in freshwater streams can indeed be strongly affected by deposits in sedimentation zones, as sediments can act as a temporary or long-term sink for pollutants, while resuspension of bed sediments during short flood periods may temporarily increase river pollution. Different mechanistic time-dependent deposition/resuspension models have been proposed in the literature (e.g., Krone 1962;Partheniades 1965;Blom and Aalderink 1998;Sanford and Maa 2001;Ha and Maa 2009;Winterwerp 2006). A ''simultaneous deposition/ erosion'' model assuming no threshold for sedimentation, as recommended by Winterwerp (2006), was selected here: it assumes that deposition of particulate contaminants always occurs and is governed by the settling velocity of particles; the erosion model is based on a threshold called ''critical shear stress of resuspension,'' corresponding to the bed stress at which initiation of erosion occurs, i.e.,…”

Section: Materials and Methods: Modelingmentioning

confidence: 99%

Linking fate model in freshwater and PBPK model to assess human internal dosimetry of B(a)P associated with drinking water

Ciffroy¹,

Tanaka

Johansson

et al. 2011

Environ Geochem Health

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In the present study, we demonstrate an integrated modeling approach for predicting internal tissue concentrations of chemicals by coupling a multimedia environmental model and a generic physiologically based pharmacokinetic (PBPK) model. A case study was designed for a region situated on the Seine river watershed, downstream of the Paris megacity, and for benzo(a)pyrene emitted from industrial zones in the region. In this case study, these two models are linked only by water intake from riverine system for the multimedia model into human body for the PBPK model. The limited monitoring data sets of B(a)P concentrations in bottom sediment and in raw river water, obtained at the downstream of Paris, were used to re-construct long-term daily concentrations of B(a)P in river water. The re-construction of long-term series of B(a)P level played a key role for the intermediate model calibration (conducted in multimedia model) and thus for improving model input to PBPK model. In order to take into account the parametric uncertainty in the model inputs, some input parameters relevant for the multimedia model were given by probability density functions (PDFs); some generic PDFs were updated with site-specific measurements by a Bayesian approach. The results of this study showed that the multimedia model fits well with actual annual measurements in sediments over one decade. No accumulation of B(a)P in the organs was observed. In conclusion, this case study demonstrated the feasibility of a full-chain assessment combining multimedia environmental predictions and PBPK modeling, including uncertainty and sensitivity analyses.

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Section: Materials and Methods: Modelingmentioning

confidence: 99%

Linking fate model in freshwater and PBPK model to assess human internal dosimetry of B(a)P associated with drinking water

Ciffroy¹,

Tanaka

Johansson

et al. 2011

Environ Geochem Health

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“…Resuspension of sediments, which is predominantly due to wind-wave action inducing orbital movement in the water of shallow lakes (Bengtsson et al, 1990;Blom et al, 1992;Blom and Aalderink, 1998), played a minor role in particle settling because of the trap shape, lake morphometry, and low current velocities (see also Fazi et al, 1995). Wind speeds sufficient to generate currents in excess of the critical shear were rare in lake Acquatina and maximum current velocities (7-8 cm s À2 ), which were very infrequent during the study period due to increased freshwater inputs and fetch, were below the velocity needed to move sediment (410-12 cm s…”

Section: à2mentioning

confidence: 99%

Detritus accumulation and decomposition in a coastal lake (Acquatina–southern Italy)

Costantini

Rossi

Fazi

et al. 2008

Aquatic Conservation

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1. Knowledge about processes and dynamics underlying organic matter accumulation in transitional waters is crucial for the protection of these ecologically important coastal habitats. This study investigated the relationship between large particle accumulation and decomposition in a coastal lake included in a Site of Community Interest (SCI) using sediment trap and litterbag techniques. 2. Two sets of sediment traps were deployed at five sites along the longitudinal axis of the lake. One set was emptied once a month for 12 months, and the other twice a year. The contents of the monthly and the 6-monthly traps and the superficial sediments were then compared to estimate the organic matter accumulation and loss. To determine the mass loss rate of the three major allochthonous sources of detritus (the reed Phragmites australis, the cordgrass Spartina juncea, and the seagrass Posidonia oceanica), litterbags were placed near the sediment traps at three out of the five sites at the beginning of each 6-month period and retrieved monthly. 3. The amount of annual particulate organic matter (POM) deposition in the traps was 1320.2 +/- 58.5 g m(-2) y(-1) and consisted of 25% large particles (CPOM). Allochthonous litter comprised an important fraction of CPOM, and its breakdown rate changed with the plant species, site and season. Loss rate of CPOM accumulated at the lake bottom was significantly related with the mass loss rate of reed and cordgrass litter, but not with that of seagrass. 4. Due to slow litter breakdown and tidal landward advection, the lake acted as a sediment trap for allochthonous matter, especially from Posidonia. The important role of marine-derived litter in organic matter sedimentation suggests addressing conservation strategies of the lake functioning towards the selective control of allochthonous CPOM inputs, in particular at the mouth where the incoming tide brings suspended material and salinity decelerates matter flow to the sea and decomposition. This study supports the hypothesis that sedimentation and decomposition dynamics are important factors for coastal lake evolution, and shows litterbag and sediment trap techniques as simple useful investigation tools in management strategies aiming at conserving transitional waters

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“…The formulation of F BC is from a classical expression of the resuspension flux as a function of the bottom shear stress (Blom and Aalderink, 1998;Ribbe and Holloway, 2001). The critical shear stress τ CR is set to 0.01 N m −2 , corresponding to the limit of resuspension for organic material (Peterson, 1999).…”

Section: Sediment Transportmentioning

confidence: 99%

Modelling an alkenone-like proxy record in the NW African upwelling

Giraud

2006

Biogeosciences

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Abstract.A regional biogeochemical model is applied to the NW African coastal upwelling between 19 • N and 27 • N to investigate how a water temperature proxy, alkenones, are produced at the sea surface and recorded in the slope sediments. The biogeochemical model has two phytoplankton groups: an alkenone producer group, considered to be coccolithophores, and a group comprising other phytoplankton. The Regional Ocean Modelling System (ROMS) is used to simulate the ocean circulation and takes advantage of the Adaptive Grid Refinement in Fortran (AGRIF) package to set up an embedded griding system. In the simulations the alkenone temperature records in the sediments are between 1.1 and 2.3 • C colder than the annual mean SSTs. Despite the seasonality of the coccolithophore production, this temperature difference is not mainly due to a seasonal bias, nor to the lateral advection of phytoplankton and phytodetritus seaward from the cold near-shore waters, but to the production depth of the coccolithophores. If coretop alkenone temperatures are effectively recording the annual mean SSTs, the amount of alkenone produced must vary among the coccolithophores in the water column and depend on physiological factors (e.g. growth rate, nutrient stress).

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Calibration of three resuspension/sedimentation models

Cited by 12 publications

References 0 publications

Linking fate model in freshwater and PBPK model to assess human internal dosimetry of B(a)P associated with drinking water

Linking fate model in freshwater and PBPK model to assess human internal dosimetry of B(a)P associated with drinking water

Detritus accumulation and decomposition in a coastal lake (Acquatina–southern Italy)

Modelling an alkenone-like proxy record in the NW African upwelling

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