Relationships between soil properties and contents in trace elements in a landscape impacted by atmospheric fallouts in Belgium

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Relationships between soil properties and

contents in trace elements in a landscape

impacted by atmospheric fallouts in Belgium

Vienna (Austria), 8th_{April 2013}

LIÉNARD AMANDINE* & COLINET GILLES

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S

TUDY

CONTEXT

Contaminated fallouts by

metallic trace elements (MTE) Cd-Cu-Pb-Zn Hosted ore

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S

TUDY

AREA

-

LOCALIZATION

Belgium

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S

TUDY

AREA

-

CHARACTERISTICS

Meuse valley Situation of old chimney Loyse river Forest Crop Grassland Village

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Impact of landscape factors on MTE distribution in soils

Interaction between soil properties and MTE contents in soils

Factors of variation MTE mobility Fate of MTE in contaminated landscape

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S

AMPLING

STRATEGY

Sampling points are distributed between 3 distinct soil types, 3 land uses and 4 wind directions (36 combinations)

1. Main soil types 2. Land use 3. Wind directions

Loamy soil with good drainage Loamy soil with poor drainage Loamy-stony soil with silexite and gravels

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M

ETHODOLOGY

i) 247 topsoil (0-20cm) samples are collected

ii) Chemical analyses :

- Pseudo-total (Aqua regia) and available (AA + EDTA (pH4.65))

contents in Ca-Mg-K-Fe-Al-Mn & Cd-Cu-Pb-Zn - pH_waterand pH_KCl

- Total Organic Carbon - N

iii) Statistical analyses :

- log transformation of all parameters excepted pH - Ancova (2 or 3 ways) with distance as covariate - Correlation

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Variation factors of MTE mobility Fate of MTE in contaminated landscape

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D

ISTANCE

FROM

SOURCE

:

T

HE MAIN FACTOR INFLUENCING

MTE

CONTENT

- Content in each MTE decreases

with distance

- P-value < 0.001 and R

2

_{> 0.5}

y = 30877x-1.248 R² = 0.5281 0 10 20 30 40 50 60 70 80 90 0 500 1000 1500 2000 2500 3000 To tal cad m iu m c o n te n t (p p m )

Source of contamination distance (m)

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D

IRECTION

OF

DOMINANT

WINDS

:

A

SECOND FACTOR WHICH INFLUENCES

MTE

CONTENT

0 1 2 3 4 5 6 7

South West North East

Cadmium content (ppm)

- Typical wind direction in Wallonia is South-West

toward North-East

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S

OIL

TYPES

:

A

THIRD FACTOR WHICH INFLUENCES THE

MTE

CONTENT

- Presence of a soil type effect for Cd – Pb – Zn total content

- Loamy-stony soils with gravels contain more MTE than

loamy soils

Loamy-Stony(Gravels) Loamy(PoorDrainage) Loamy(GoodDrainage) 3.5 3.0 2.5 2.0 1.5

Lead total (log(ppm))

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S

OIL

TYPES

:

A

THIRD FACTOR WHICH INFLUENCES THE

MTE

CONTENT

Effect maybe due to their position in the landscape

Loamy soil with

good drainage

Loamy soil with poor drainage

Stony-loamy soil with gravels

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L

AND

USE

:

A

LAST FACTOR WHICH INFLUENCES THE

MTE

CONTENT

Grassland Forest Crop 4.0 3.5 3.0 2.5 2.0

Zinc total (log(ppm))

a a a Grassland Forest Crop 3.5 3.0 2.5 2.0 1.5

Lead total (log(ppm))

b a b

- Two different situations of MTE according to land use

- Cd and Zn total content are not impacted by land use in

opposite to Cu and Pb total content

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C

ONFIRMATION

BY

PCA

ANALYSIS

0.4 0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3 0.50 0.25 0.00 -0.25 -0.50 -0.75 First Component S e co n d C o m p o n e n t Distance South West East North Forest Grassland Crop

Loamy soil (poor drainage)

Loamy soil (good drainage)

Stony-loamy (gravels) ZnTot PbTot CuTot CdTot ZnAvail. PbAvail. CuAvail. CdAvail. Principal Component Analysis (TS- LU - WD - Distance - MTE)

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Variation factors of MTE mobility Fate of MTE in contaminated landscape

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R

ELATION

BETWEEN

SOIL

PROPERTIES

AND

LANDSCAPE

FACTORS

0.4 0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3 0.5 0.4 0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3 -0.4 First Component S e co n d C o m p o n e n t Distance South West East North Forest Grassland Crop Loamy (PD) Loamy (GD) Loamy-stony MnTot AlTot FeTot KTot MgTot CaTot MnAvail. PAvail AlAvail. FeAvail. KAvail. MgAvail. CaAvail. N COT pHKCl pHEau

Principal Component Analysis (TS - LU - WD - Distance - Soil parameters)

- No influence of soil type and distance

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R

ELATION

BETWEEN

P

H

_KCL

- COT

AND

LANDSCAPE

FACTORS

- Distance and wind directions factors

don’t affect pH_KCl and COT values in soils

- Soil type and land use influence pH and COT values in soils

Grassland Forest Crop 8 7 6 5 4 3 pHKCl a c b

Comparison of MTE and pH

_KCl

– COT

Distance Wind

direction Soil type Land use MTE

Yes Yes Yes

(Cd-Pb-Zn)

Yes (Cu–Pb)

pH_KCl No No Yes Yes

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Variation factors of MTE mobility

Fate of MTE in contaminated landscape

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R

ELATION

BETWEEN

MTE

AVAILABLE

/

TOTAL

RATIO

AND

S

OIL

TYPE

– L

AND

USE

FACTORS

- Cd ratio is not influenced by the two factors

- Cu -Pb and Zn ratio are different according to land use  ratio on forest is always highest

- Zn ratio is modified by soil type  loamy-stony soil contains a high proportion of Zn available content

In forest, the fraction of potentially mobile Cu – Pb and Zn are more higher as Zn in loamy-stony soil Grassland Forest Crop 0.65 0.60 0.55 0.50 0.45 0.40 M e a n ( lo g (p p m )) Pb available/total Loamy-Stony(Gravels) Loamy(PoorDrainage) Loamy(GoodDrainage) 0.22 0.21 0.20 0.19 0.18 0.17 0.16 M e a n ( lo g (p p m )) Zn available/total

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Factors of variation MTE mobility Fate of MTE in contaminated landscape

C

ONCLUSION

-Important impacts for distance and wind directions

- Soil and land use are

also significant - Classical relations

- pH and COT variability is different than MTE

Soil type and land use impact MTE mobility

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R

ELATION

BETWEEN

Z

N

/P

B

AND

Z

N

/C

D

R² = 0.7257 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Pb To t co n te n t (l o g(p p m ))

Zn Tot content (log(ppm))

Relation between Zn Tot and Pb Tot

R² = 0.8448 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Cd To t co n te n t (l o g(p p m ))

Zn Tot content (log(ppm))

Relation between Zn Tot and Cd Tot

-Contaminants contents are strongly correlated one with the other.

- It thus seems that they have the same signature in term of landscape dispersion