IJUP08 - Universidade do Porto

Influence of organic pollutants on phytoremediation of copper by
a salt marsh plant
A. C. M. Dias 1,2* , C. M. R. Almeida 2 , A. P. Mucha 2 and M. T. S. D.Vasconcelos 1,2
1 Department of Chemistry, Faculty of Sciences, University of Porto, Portugal.
2 CIMAR/CIIMAR - Centre of Marine and Environmental Research, University of Porto, Portugal
* ana.lau.dias@gmail.com
Metal-contaminated soil can be remediated or cleanup by chemical, physical or biological
techniques [1].
Plants may participate in decontamination either directly, by the uptake of pollutants and
their immobilization, degradation or transformation within the plant, or indirectly by
creating a rhizosphere environment (region where the soil and the roots of the plants come
in contact) which promotes degradation by bacterial or fungal species.
Sites contaminated with trace metals are frequently and unfortunately also contaminated
with organic pollutants of different families. The simultaneous presence of pollutants of
different groups might cause antagonisms or synergisms effects on the biological
remediation processes, because different chemicals may interact among themselves and
with the organisms present at rhizosphere, thus changing remediation efficiency. Studies of
metal accumulation in plants from estuarine sediments contaminated with a mixture of
inorganic and organic pollutants are scarce, although deserve investigation because
estuaries are often considered sinks for varied pollutants.
This study aims to investigate the effect of some organic compounds which are frequently
present in polluted environments, like PAHs, pesticides and organotins, on the uptake of
metals, like copper (Cu), by the salt marsh plant Halimiones portulacoides. This plant was
selected because it is commonly found in Portuguese temperate salt marshes and is capable
of accumulating several metals, including Cu [2]. For this purpose, ex-situ and in
hydroponics experiments are being carried out using sediment and water from a salt marsh
from Cávado River estuary. Sets of plants collected at the same site are being exposed to
known concentrations of both Cu and a specific organic pollutant, during 6 days.
Afterwards, Cu will be determine in the media and in plant dried tissues (roots, stems and
leaves) by atomic absorption spectrometry, after digestion assisted by high pressure
microwave.
Whether the results indicate antagonistic or synergistic effects, the simultaneous presence
of pollutants of different families should be taken in consideration in future studies of
suitability of plants for remediation, including phytostabilization.
References:
[1] McEldowney S., Hardman D. J., Waite S. (1993). Treatment technologies, in S. McEldowney
S., Hardman D. J., Waite S (Eds.). Pollution, ecology and biotreatment, Singapore pp. 48-58,
Longman Singapore Publishers Pvt. Ltd.
[2] Caçador, I., Vale, C., Catarino, F., (2000). Seasonal variation of Zn, Pb, Cu and Cd
concentrations in the root-sediment system of Spartina maritima and Halimione portulacoides
from Tagus estuary salt marshes. Marine Environmental Research 49, 279-290.
Acknowledgement: This work was partially funded by Fundação para a Ciência e Tecnologia
(FCT), Portugal, through project POCTI/CTA/48386/2002.
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