Research output: Scientific - peer-review › Article

**Cadmium transport in sediments by tubificid bioturbation: an assessment of model complexity.** / Delmotte, S.; Meysman, F.J.R.; Ciutat, A.; Boudou, A.; Sauvage, S.; Gerino, M.

Research output: Scientific - peer-review › Article

Delmotte, S, Meysman, FJR, Ciutat, A, Boudou, A, Sauvage, S & Gerino, M 2007, 'Cadmium transport in sediments by tubificid bioturbation: an assessment of model complexity' *Geochimica et Cosmochimica Acta*, vol 71, no. 4, pp. 844-862. DOI: 10.1016/j.gca.2006.11.007

Delmotte, S., Meysman, F. J. R., Ciutat, A., Boudou, A., Sauvage, S., & Gerino, M. (2007). Cadmium transport in sediments by tubificid bioturbation: an assessment of model complexity. *Geochimica et Cosmochimica Acta*, *71*(4), 844-862. DOI: 10.1016/j.gca.2006.11.007

Delmotte S, Meysman FJR, Ciutat A, Boudou A, Sauvage S, Gerino M. Cadmium transport in sediments by tubificid bioturbation: an assessment of model complexity. Geochimica et Cosmochimica Acta. 2007;71(4):844-862. Available from, DOI: 10.1016/j.gca.2006.11.007

@article{c3c8fd57257241d3873a8cb3563ec136,

title = "Cadmium transport in sediments by tubificid bioturbation: an assessment of model complexity",

abstract = "Biogeochemistry of metals in aquatic sediments is strongly influenced by bioturbation. To determine the effects of biological transport on cadmium distribution in freshwater sediments, a bioturbation model is explored that describes the conveyor-belt feeding of tubificid oligochaetes. A stepwise modelling strategy was adopted to constrain the many parameters of the model: (i) the tubificid transport model was first calibrated on four sets of microspheres (inert solid tracer) profiles to constrain tubificid transport; (ii) the resulting transport coefficients were subsequently applied to simulate the distribution of both particulate and dissolved cadmium. Firstly, these simulations provide quantitative insight into the mechanism of tubificid bioturbation. Values of transport coefficients compare very well with the literature, and based on this, a generic model of tubificid bioturbation is proposed. Secondly, the application of the model to cadmium dataset sheds a light on the behaviour of cadmium under tubificid bioturbation. Cadmium enters the sediment in two ways. In one pathway, cadmium enters the sediment in the dissolved phase, is rapidly absorbed onto solid particles, which are then rapidly transported to depth by the tubificids. In the other pathway, cadmium is adsorbed to particles in suspension in the overlying water, which then settle on the sediment surface, and are transported downwards by bioturbation. In a final step, we assessed the optimal model complexity for the present dataset. To this end, the two-phase conveyor-belt model was compared to two simplified versions. A solid phase-only conveyor-belt model also provides good results: the dissolved phase should not be explicitly incorporated because cadmium adsorption is fast and bioirrigation is weak. Yet, a solid phase-only biodiffusive model does not perform adequately, as it does not mechanistically capture the conveyor-belt transport at short time-scales.",

author = "S. Delmotte and F.J.R. Meysman and A. Ciutat and A. Boudou and S. Sauvage and M. Gerino",

note = "Reporting year: 2007 Metis note: 3929;CEME; ES; file:///C:/pdfs/Pdfs2007/Delmotte_ea_3929.pdf",

year = "2007",

doi = "10.1016/j.gca.2006.11.007",

volume = "71",

pages = "844--862",

journal = "Geochmica et Cosmochimica Acta",

issn = "0016-7037",

publisher = "Elsevier",

number = "4",

}

TY - JOUR

T1 - Cadmium transport in sediments by tubificid bioturbation: an assessment of model complexity

AU - Delmotte,S.

AU - Meysman,F.J.R.

AU - Ciutat,A.

AU - Boudou,A.

AU - Sauvage,S.

AU - Gerino,M.

N1 - Reporting year: 2007 Metis note: 3929;CEME; ES; file:///C:/pdfs/Pdfs2007/Delmotte_ea_3929.pdf

PY - 2007

Y1 - 2007

N2 - Biogeochemistry of metals in aquatic sediments is strongly influenced by bioturbation. To determine the effects of biological transport on cadmium distribution in freshwater sediments, a bioturbation model is explored that describes the conveyor-belt feeding of tubificid oligochaetes. A stepwise modelling strategy was adopted to constrain the many parameters of the model: (i) the tubificid transport model was first calibrated on four sets of microspheres (inert solid tracer) profiles to constrain tubificid transport; (ii) the resulting transport coefficients were subsequently applied to simulate the distribution of both particulate and dissolved cadmium. Firstly, these simulations provide quantitative insight into the mechanism of tubificid bioturbation. Values of transport coefficients compare very well with the literature, and based on this, a generic model of tubificid bioturbation is proposed. Secondly, the application of the model to cadmium dataset sheds a light on the behaviour of cadmium under tubificid bioturbation. Cadmium enters the sediment in two ways. In one pathway, cadmium enters the sediment in the dissolved phase, is rapidly absorbed onto solid particles, which are then rapidly transported to depth by the tubificids. In the other pathway, cadmium is adsorbed to particles in suspension in the overlying water, which then settle on the sediment surface, and are transported downwards by bioturbation. In a final step, we assessed the optimal model complexity for the present dataset. To this end, the two-phase conveyor-belt model was compared to two simplified versions. A solid phase-only conveyor-belt model also provides good results: the dissolved phase should not be explicitly incorporated because cadmium adsorption is fast and bioirrigation is weak. Yet, a solid phase-only biodiffusive model does not perform adequately, as it does not mechanistically capture the conveyor-belt transport at short time-scales.

AB - Biogeochemistry of metals in aquatic sediments is strongly influenced by bioturbation. To determine the effects of biological transport on cadmium distribution in freshwater sediments, a bioturbation model is explored that describes the conveyor-belt feeding of tubificid oligochaetes. A stepwise modelling strategy was adopted to constrain the many parameters of the model: (i) the tubificid transport model was first calibrated on four sets of microspheres (inert solid tracer) profiles to constrain tubificid transport; (ii) the resulting transport coefficients were subsequently applied to simulate the distribution of both particulate and dissolved cadmium. Firstly, these simulations provide quantitative insight into the mechanism of tubificid bioturbation. Values of transport coefficients compare very well with the literature, and based on this, a generic model of tubificid bioturbation is proposed. Secondly, the application of the model to cadmium dataset sheds a light on the behaviour of cadmium under tubificid bioturbation. Cadmium enters the sediment in two ways. In one pathway, cadmium enters the sediment in the dissolved phase, is rapidly absorbed onto solid particles, which are then rapidly transported to depth by the tubificids. In the other pathway, cadmium is adsorbed to particles in suspension in the overlying water, which then settle on the sediment surface, and are transported downwards by bioturbation. In a final step, we assessed the optimal model complexity for the present dataset. To this end, the two-phase conveyor-belt model was compared to two simplified versions. A solid phase-only conveyor-belt model also provides good results: the dissolved phase should not be explicitly incorporated because cadmium adsorption is fast and bioirrigation is weak. Yet, a solid phase-only biodiffusive model does not perform adequately, as it does not mechanistically capture the conveyor-belt transport at short time-scales.

U2 - 10.1016/j.gca.2006.11.007

DO - 10.1016/j.gca.2006.11.007

M3 - Article

VL - 71

SP - 844

EP - 862

JO - Geochmica et Cosmochimica Acta

T2 - Geochmica et Cosmochimica Acta

JF - Geochmica et Cosmochimica Acta

SN - 0016-7037

IS - 4

ER -

ID: 109747