References of "Dere, Christelle"
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See detailSpatial distribution of metallic trace elements in soils contaminated by atmospheric fallouts. Case study: Sclaigneaux (Belgium)
Liénard, Amandine ULg; Colinet, Gilles ULg; Dere, Christelle ULg

Conference (2012, July 03)

The valleys of Sambre and Meuse in Wallonia hosted numerous metal ore treatment factories. They engendered a contamination of soils by metallic trace elements that may migrate in the landscape through ... [more ▼]

The valleys of Sambre and Meuse in Wallonia hosted numerous metal ore treatment factories. They engendered a contamination of soils by metallic trace elements that may migrate in the landscape through erosion, lixiviation, biological transportation, aso. We investigated the spatial distribution of some metallic trace elements in soils around a former zinc-ore treatment plant to a distance of 3km. The sampling strategy aimed at (i) verifying that the main source of trace elements was the plant chimney, (ii) assessing the impact of the wind directions on fallout dispersion and (iii) evaluating whether there were differences of contents according to soil types and to soil occupation. Two hundred and fifty topsoil samples were collected according to a stratified design dealing with distance to the chimney, direction of dominant winds, soil type, and land use. Pseudo-total contents in inorganic elements, pH, TOC, and N were determined in the laboratory. Besides, classical statistical analysis (i) ANCOVA (three-way ANOVA with the distance as a co-variate) and (ii) Principal Component Analysis were also performed. First results show that (i) zinc, lead and cadmium contents are closely correlated to each other and (ii) negatively correlated with the distance. If the geographical location is the major driving factor of trace elements contents in soils, significant differences were also found between soil type and land use (p-value<0.05). The highest MTE concentrations were associated with North-East winds, forest cover and pebbles rich soils. Further investigations will concern the vertical and toposequential distributions, and the speciation of MTE. [less ▲]

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See detailFate of zinc in a sandy Luvisol submitted to 100 years of massive irrigation with raw waste waters: a multi-scale approach
Dere, Christelle ULg; Lamy, Isabelle; Cornu, Sophie

Conference (2007, July)

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See detailLong-term fate of exogenous metals in a sandy Luvisol subjected to intensive irrigation with raw wastewater
Dere, Christelle ULg; Lamy, Isabelle; Jaulin, Anne et al

in Environmental Pollution (2007), 145

From 1899 to 2002, sandy Luvisol in the Paris region has been intensively irrigated with raw wastewater, resulting in major soil pollution by metallic trace elements (MTE). To identify the soil phases ... [more ▼]

From 1899 to 2002, sandy Luvisol in the Paris region has been intensively irrigated with raw wastewater, resulting in major soil pollution by metallic trace elements (MTE). To identify the soil phases implicated in retaining these metals, sequential extractions were performed on a solum irrigated with untreated wastewater and another reference solum. The endogenous and exogenous fractions of MTE in the contaminated soil were discriminated using correlations between MTE and major elements defined from unpolluted soils of the area. In the contaminated soil no exogenous lead and chromium are present below the surface horizon, whereas exogenous zinc and copper are found down to the base of the solum. The endogenous MTE are mainly found in the residual fraction. Exogenous MTE appear to be associated with organic matter in the surface horizon, and exogenous zinc seems to be readsorbed on iron and manganese oxyhydroxides in the underlying horizons. [less ▲]

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See detailFactors affecting the three-dimensional distribution of exogenous zinc in a sandy Luvisol subjected to intensive irrigation with raw wastewaters.
Dere, Christelle ULg; Cornu, Sophie; Lamy, Isabelle

in Soil Use and Management (2006), 22

Massive volumes of raw wastewater have been spread on sandy Luvisols in the Paris region since 1899, causing major soil contamination with metallic trace elements (MTE). To identify the factors ... [more ▼]

Massive volumes of raw wastewater have been spread on sandy Luvisols in the Paris region since 1899, causing major soil contamination with metallic trace elements (MTE). To identify the factors influencing the vertical and horizontal redistribution of MTE at the plot scale, a study was carried out of the three-dimensional distribution of zinc. The background and exogenous fractions of zinc in the contaminated soil were discriminated using correlations between zinc and iron defined from unpolluted soils of the area. At the surface, the spatial distribution of zinc is determined by the geometry of the irrigation system and the terrain topography. The highest concentrations are observed near the irrigation outlets and in areas of very slight slope. The exogenous zinc has migrated down to the base of the studied solums (1 m depth), and its subsurface distribution depends upon the physico-chemical properties of the horizons. In the E horizon, the trapping of exogenous zinc is governed by the number of available reactive sites, whereas in the Bt horizon it is a function of the vertical and lateral behaviour of the drainage. Moreover, lateral transfer of exogenous zinc occurs in the C horizon. In the case of soil contaminated with raw wastewater, the organization of water flow on the surface and in the subsurface is a determining factor in the redistribution of zinc within a plot. [less ▲]

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See detailEnhancing spatial estimates of metal pollutants in raw wastewater irrigated fields using a topsoil organic carbon map predicted from aerial photography
Bourennane, Hocine; Dere, Christelle ULg; Lamy, Isabelle et al

in Science of the Total Environment (2006), 361

Various approaches have been used to estimate metal pollutant element (TE) contents at unsampled locations in a 15-ha contaminated site located in the plain of Pierrelaye–Bessancourt (about 24 km ... [more ▼]

Various approaches have been used to estimate metal pollutant element (TE) contents at unsampled locations in a 15-ha contaminated site located in the plain of Pierrelaye–Bessancourt (about 24 km Northwest of Paris). 87 samples of soil plough layer were randomly sampled at each mesh of a regular square grid over the whole study area and the total contents of Cd, Cr, Cu, Ni, Pb, and Zn were measured. A first set of 50 measurements, randomly selected from the 87 samples, was used for the prediction and another set of 37 measurements was kept for the validation. Topsoil organic carbon contents (SOC) were measured at 75 sites with 50 measurements sharing the same locations as TE. An aerial photography of the study area showing bare soils was selected for relating brightness intensities and SOC. Mapping procedures used were ordinary kriging (OK), cokriging (COK), collocated cokriging (CC), and kriging with external drift (KED). SOC maps used as exhaustively sampled information in KED and CC of TE were obtained by KED and CC procedures, respectively, accounting for 75 SOC measurements and the brightness intensities of numerical counts provided by the visible bands of the aerial photograph bare soils. Consequently, for each TE, four maps were generated: two maps resulting from KED and CC procedures (KED-SOC75P, CC-SOC75P), another one provided by standard cokriging (COK-TE50SOC75) accounting for TE prediction set plus 75 SOC measurements, and the last one corresponding to that estimated by ordinary kriging from only prediction set measurements (OK50). Three indices: (1) the mean prediction error (ME) and the mean absolute prediction error (|ME|); (2) the root mean square error (RMSE); and (3) the relative improvement (RI) of accuracy, as well as residuals analysis, were computed from the validation set (observed data) and predicted values. On the 37 test data, the results showed that the more accurate predictions were systematically those obtained by kriging accounting for SOC map predicted by KED from 75 SOC measurements and brightness values of the aerial photo (KED-SOC75P) followed closely by CC-SOC75P procedure, except for Cu and Zn where CC-SOC75P appeared to be slightly more accurate than KED-SOC75P. In regard to the RI of accuracy between prediction methods, the results confirmed once for all the benefit of accounting for SOC data set plus the exhaustively sampled information provided by the aerial photography regardless of the considered TE. Nevertheless, for Cd, Pb, and Zn, the RI of accuracy was less than 20% between the two most accurate methods (KED-SOC75P and CC-SOC75P) and standard cokriging in which the information provided by the aerial photography is ignored when mapping. The sensitivity of KED-SOC75P and CC-SOC75P approaches to the sampling density of the target variables (TE) was assessed using 10 random subsets of different sizes (25 and 33 observations) drawn from a prediction set that includes 50 data. Results have shown that the TE estimates by KED-SOC75P and CC-SOC75P approaches using only 25 TE samples were much more accurate than the estimates performed by OK50 and COK-TE50SOC75 approaches that use the whole samples of the prediction set. Moreover, the RI of accuracy was reduced by less than 15% if the original sampling density was reduced by a third. [less ▲]

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See detailUse of major- and trace-element correlations to assess metal migration in sandy Luvisols irrigated with wastewater
Lamy, Isabelle; van Oort, Folkert; Dere, Christelle ULg et al

in European Journal of Soil Science (2006), 57

Soils irrigated with raw wastewater for many years accumulate trace metals, especially in the surface horizon. We do not know, however, to what extent the metals migrate down the profile and whether they ... [more ▼]

Soils irrigated with raw wastewater for many years accumulate trace metals, especially in the surface horizon. We do not know, however, to what extent the metals migrate down the profile and whether they accumulate in deeper horizons. We assessed the migration of trace metals in the suburbs of Paris where market gardens had been irrigated with wastewater for more than 100 years. Within a soil series, we compared metals in the polluted soils with those of a reference soil of the same kind. We sampled by horizons three representative Luvisol profiles in the irrigated area and a fourth profile selected as a reference just outside the irrigated area. Large quantities of Zn, Pb, Cd and Cu appeared to have accumulated in the topsoil, at the base of which concentrations diminished markedly. There appeared to be appreciable migration into the subsoil only at the most intensely irrigated site. By relating the total trace metal contents to the total iron contents we could detect anomalous values and identify migration into the subsurface horizons more sensitively. This approach was tested first with the endogenous metal Cr, then with metal pollutants. We showed that Zn, Pb, Cd and Cu migrated downwards in all three irrigated soils. [less ▲]

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See detailTrace metal inputs reconstitution and migration assessment in a sandy Luvisol after 100 years of massive irrigation with raw wastewaters
Dere, Christelle ULg; Lamy, Isabelle; Cornu, Sophie et al

in Comptes Rendus Geoscience (2006), 338

Trace metal inputs reconstitution and migration assessment in a sandy Luvisol after 100 years of massive irrigation with raw wastewaters. Raw wastewaters were massively spread on sandy luvisols near Paris ... [more ▼]

Trace metal inputs reconstitution and migration assessment in a sandy Luvisol after 100 years of massive irrigation with raw wastewaters. Raw wastewaters were massively spread on sandy luvisols near Paris from 1899 to 2002, leading to high trace metals (TM) pollution of soils. Mass balance calculations were performed on a soil profile to assess vertical migration of TM. The contamination was estimated by subtracting the natural pedo-geochemical background of the horizons. TM inputs were estimated using Cr as an invariant. It is shown that Pb and Cr remained in the surface horizon, while Ni, Cd, Cu and Zn migrated downward, being more or less trapped depending on the physicochemical properties of the horizons. [less ▲]

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See detailStocks and fluxes of metals in a Luvisol of a contaminated suburban field.
Dere, Christelle ULg; Lamy, Isabelle; Cornu, Sophie et al

Poster (2003, June)

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See detailDistribution of polluting trace metals along a toposequence in a contaminated suburban field
Dere, Christelle ULg; Cornu, Sophie; Lamy, Isabelle et al

Poster (2002, August)

Detailed reference viewed: 15 (1 ULg)