Monitoring of subsurface pollution by use of vegetation samples

Stefan Trapp1, Ulrich Karlson2 & Dietmar Pieper3

1 Environment & Resources

Technical University of Denmark

stt@er.dtu.dk

2 NERI 3 GBF

Stefan Trapp CV

1962 * Germany

1986 dipl geoecology

1992 PhD botany

1998 habil mathematics

1998 DTU applied ecology

2004 BIOTOOL

Table of Contents

Monitoring of subsurface pollution by use of vegetation samples

1 The BIOTOOL project

2 Effects on plants

3 Uptake into plants

4 Conclusions

http://www.gbf.de/biotools/index.html

Coordinator Dietmar Pieper, GBF

BIOTOOLBiological procedures for diagnosing the status

and predicting evolution of polluted environments

Dietmar Pieper German Research Centre for Biotechnology, DVictor de Lorenzo CSIC, ESStefan Trapp Technical University of Denmark, DKChristof Holliger Ecole Polytechnique Federale de Lausanne, CHVladimir Brenner Czech Academy of Sciences, CZUlrich Karlson National Environmental Research Institute, DKHermann Heipieper Centre for Environmental Research, D Jan Jurak KAP Ltd, CZJuan Rodriguez BIONOSTRA S.L., ES

some BIOTOOL partners

Howard Junca & Dietmer Pieper

Victor de Lorenzo Ulrich KarlsonHermann, Nadja, Janett UFZ

Maria Brennerova

Chris Hollinger

Natural attenuation is predominantly a biologically driven process

We require information on

- whether it can occur

- whether it is actually occurring at a significant rate

- which mechanisms and pathways are involved

- how it will behave in the future

Biological fate of tetrachloroethene

Cl

Cl Cl

Cl

tetrachloroethene(PCE) Testing in microcosms

for 5 months2[H]HCl

Cl

Cl Cl

H

trichloroethene(TCE)

2[H]HCl

H

Cl Cl

H

cis-1,2-dichloroethene(cis-1,2-DCE)

Under identical physico/chemical conditions, different metabolic reactions are observed

PCE transforming activity seems to be ubiquitous, vinylchloride transformation not

H

Cl H

H

2[H]HCl

vinyl chloride(VC)

H

H H

H

2[H]HCl

etheneMAROC, Holliger et al.

Opening the black box of environmental microbiology

Biological markers of degradation

H

Cl Cl

H

H

Cl H

H

H

H H

H

Cl

Cl Cl

Cl

Bacteria In some cases specific groups of bacteria are known to be predominantly responsible for a certain metabolic capability

DNA Catabolic genes can be detected by culture-independent analyses

RNA Shows which genes are actually expressed and thus indicates activity

Proteins Indicators for the status of the cell

Lipids Adaptation of bacteria to stress and pollutants

The problem

Insufficient tools to assess, evaluate and predict biological mediated natural attenuation processes

The solutionBiological procedures for diagnosing the status and

predicting evolution of polluted environments

Objective

To develop instruments for diagnosis of the catabolic status and prediction of site biodegradation trends

COOH

X

OH

XX

X

OCH2COOH

X

NH2

X

X

CH3

X

COOH

X

OH

O O O

X X

OHOH

XCOOH

OH

CHOX

X

COOHCOOH

Metabolic networks

Catabolic gene fingerprinting gives information on

Genes abundant at the site of interestDiversity of genesand generally the catabolic gene landscape

Catabolic gene arrays to rapidly analyze catabolic gene landscapesare under development

Detection of mRNA

A B C A B C

rRNA

rRNAextract without purification

extract after purification

BIOTOOL specific objectives

- Design and utilization of DNA and DNA–arraytechnology for examining the catabolic potential ofsamples

- Access and analysis of the soil/groundwater meta-proteome as biomarker

- Use of lipid biomarkers as prediction instruments ofstress/toxicity on soil and groundwater microorganisms

-Establishment of the correlation betweensoil/groundwater contamination and plant contamination

Overview of BIOTOOL field sites

Denmark

Glostrup, former rain water lagoon; TCE

Axelved, former petrol station; diesel & gasoline

Vassingerød, former asphalt works; diesel and PAH

Søllerød, former gas works; CN, PAH and BTX

Czech Republik

Hradcany, former USSR-air base; jet fuel

SAP, carcasses disposal plant; PCE

Field sites in Denmark

former tank station former asphalt works

Axelved: gasoline & diesel

Vassingerød:diesel & PAH

Former gas works Søllerød

Cyanides PAH, BTEX

1951

2001

Field site in Czech Republik: Hradcany(former Russian military airport)

Hradcany airport

Pollution: jet fuel

BIOTOOL workpackage 2

Plant monitors to analyze subsurface contamination

The normal engineer makes many bore holes

to find sub-surface pollution

The lazy engineer takes plant samples

... but will it help him?

Hypothesis 1If soils are polluted,

effects on plants indicate subsurface pollution

Louise

Henning

Example 1: Gas works waste

Photo: Gas works waste in Amager

Composition of gas works waste

Typically

Iron cyanide FexCNyup to 50 g/kg

PAH up to 1000 mg/kg

Sulphur up to 50%

Evil substrate!

Field observation 1

This gas works waste was deposited > 30 years ago.

Still no plants grow on it.

Is gas works waste toxic to plants?

Field observation 2

Vegetation established well on other gas workswaste.

Is gas works wastenon-toxic to plants ?

What now?

Photo: Tim Mansfeldt

Laboratory tests on phytotoxicityWillow tree transpiration test

Lab results

Iron cyanide is quite non-toxic to plants.

PAH (≤ 1600 mg/kg soil) are non-toxic, too.

What is the toxic principle?

Louise's result

Low pH (< 2) kills the plants. At pH > 3.3 plants can grow.

After liming, all tested species could grow in this gas works waste

S H2SO4 pH 2

Example 2: Axelved, former petrol station

Photo: Axelved 1999 (2nd season)

Axelved 1999, plume center

In 1 – 3 m depth ~ 3000 mg diesel / kg soil

Tree height 2000 (3rd season)

Plume center

Tree height measurements winter 2005

Method

• Height measurement with a telescopic bar

• Average distance between trees 0.5 m

• Comparison to chemical data from student excursions

Ulrich Reiter, ETH

Correlation between tree height and soil contamination in Axelved 2005

Not significant !

R2 < 0.1

Laboratory test of phytotoxicity

Soil samples from Axelved

with diesel + gasoline from 500 to 20 000 mg/kg

were lab-tested for toxicity with willow trees.

Tox-criterion was inhibition of transpiration.

Helle Christiansen

Phytotoxicity of samples from Axelved

0

0.2

0.4

0.6

0.8

1

1.2

100 1000 10000 100000

C5-C28 mg/kg

I

LogNorm curve fit Observed values EC50 EC10

outsite 2005

Conclusion: Contamination in Axelved 2005 is too low to show effects on tree growth.

Example 3: Asphalt works Vassingerød

Tree grows on free-phase diesel

normal tree

Uli Karlson

Positive relation contamination – growth?

Example 3: Asphalt works Vassingerød

N

former building structure seems to determine tree growth (not contamination)

Preliminary conclusions for hypothesis 1

"If soils are polluted, effects on plants indicate subsurface pollution"

1 What is toxic for us is not toxic to trees (CN, PAH ...)

2 What is toxic to trees (pH, salt etc.) is not necessarily our problem

3 Many variables influence the growth of trees, the correlation to pollution can be uncertain (weak)

Hypothesis 2

If soil and/or ground-water are polluted

chemicals will be found in stem, leaves or fruits

and may be used to indicate subsurface pollution.

Translocation upwards

A ”standard plant” transpires 500 L water for the production of 1 kg dry weight biomass!

= approx. 1 L/day/m2

good chance for upwards-transport of chemicals

Correlation between soil and plant contamination

Measuring campaign starts June 2005

No own data available yet

Pre-selection of compounds with models

Modeling uptake of pollutants into plants

Relevant processes

Uptake by diffusion

Uptake by advection

Transport in xylem

Volatilization from stem and leaves

Metabolism by plant & bacteria

Advective uptake into roots

Change of mass in roots =

+uptake with water – transport to shoots

dmR/dt = CWQ – CXyQ

where Q is water flow [L d-1]

Diffusion across the peel is neglected!

Dilution by growth

0

25

50

75

100

0 24 48 72

Time

Plan

t mas

s,

conc

entr

atio

n

M (kg) m/M (mg/kg)

Chemical mass: m = constant

Plant Mass: M(t) = M(0) x e+kt

m/M = Concentration in plant: C(t) = C(0) x e-kt

Root concentration

Change of concentration in roots =

+ uptake with water

– transport to shoots

– dilution by growth

dCR/dt = CWQ/M – CXyQ/M – kCR

where k is growth rate [d-1] and CXy is the concentration in xylem = CR/KRW

Root model steady-state (dC/dt=0)

W

RW

R CkM

KQ

QC+

=

RRWRWR CkMQKCMQC

dtdC

×−×−×= ///

)(/ kMK

QCMQCRW

RW −×

×=×

Growth

Root to soil - steady-state

0.0

0.5

1.0

1.5

2.0

1 2 3 4 5 6log Kow

BCF

root

to s

oil

(fre

sh w

eigh

t)

Equilibrium C Carrot

WS

RW

WSW

R

Soil

R KkM

KQ

QKCC

CC

BCF ×+

=×==

no growth, k = 0

with growth

Translocation upwards in the xylem

Transpiration stream concentration factor TSCF

RW

RW

RWW

R

W

Xy KkM

KQ

QKCC

CC

TSCF //+

===

0

0.4

0.8

1.2

-1 0 1 2 3 4 5 6

log Kow

TSC

F

Briggs B+S CXy

Tree model

Influx with xylem = Q x CW x TSCF

Q is transpired water (m3/a)

Loss with xylem = Q × CStem /KWood

WoodStemWStem KCQTSCFCQ

dtdm

/×−××+=

Sorption to wood

Kwoodlog

KWood = CWood / Cw

log KWood = – 0.27 + 0.632 log KOW(oak)

log KWood = – 0.28 + 0.668 log KOW(willow)

Lignin is a good sorbent for lipophilic chemicals!

Movement in stem relative to water Delayed due to retention in the stem

Source: Trapp, Miglioranza, Mosbæk Env. Sci. Technol. 2001

Conclusion from modeling

Only

persistent

non-volatile and

water-soluble chemicals

will be efficiently translocated to stem and leaves !

Promising indicator compounds

Heavy metals: copper, cadmium

Many herbicides & other pesticides

TCE and its metabolite TCAA

IRON for FexCNy

Naphthalene as only PAH

RDX explosive

For diesel & gasoline ??

All results are preliminary – this project has just started!

SummaryMonitoring of subsurface pollution by use of vegetation

... might be more difficult as it seems at firstbut provides the chance to save many boreholes!

Thanks for your interest

stt@er.dtu.dk

The End