4th EucheMs chemistry congress

tuesday, 28-Aug 2012
s644
chem. Listy 106, s587–s1425 (2012)
Environment and Green Chemistry
Mining and the Environment – Assessing environmental
impacts
o - 1 5 3
the iMPACt of MetAL MininG on SeLeCted
river SySteMS in roMAniA
M. SiMA 1 , J. zoBriSt 2 , G. Bird 3 , B. doLd 4 ,
M. SeniLA 5 , d. BALteAnu 1
1 Romanian Academy, Institute of Geography, Bucharest,
Romania
2 Eawag, Water Resources and Drinking Water, Duebendorf,
Switzerland
3 Bangor University, School of Environment Natural Resources
and Geography, Bangor, United Kingdom
4 University of Chile, Geology Department, Santiago de Chile,
Chile
5 Research Institute for Analytical Instrumentation, Donath
Street, Cluj-Napoca, Romania
Base and precious metal mining is one of the human
activities with significant impact on the rivers, introducing large
quantities of heavy metals and other contaminants into the river
drainage. Romania has a long tradition in metal mining, the ore
exploitation and processing being now closed, which impose a
new perspective on sustainable long-term management of mine
waste and mining site rehabilitation, as many such deposits
continue to produce acid drainage with adverse effects on the
environment.
The paper aims to provide an overview of the most
contaminated river systems in Romania, assessing their behavior
in time, starting from the year 2000, when two tailings dam
failures in Maramures County strongly affected the Tisza-Danube
river systems. The study utilizes geochemical data to assess the
dispersal of metal contaminants from the mining source along the
river systems by assessing metal concentration in several
environments: surface and underground water, channel and
floodplain sediments and mine tailings. An example of acid mine
drainage formation within an active mine tailings dam (e.g. Mialu,
Certej catchment) will be given, this being an importance source
of mining-related contaminants in the fluvial system. Lead
isotopes ( 204Pb, 206Pb, 207Pb and208Pb) have been utilized as
geochemical tracers of the anthropogenic activities in the lower
Danube Basin (mainly from Romania, Serbia and Bulgaria) in
order to identify the isotopic signature of different ore deposits
and to characterize mining affected river catchments, representing
important information for the management and remediation
practices. Even the metal mining is now closed in Romania, the
improperly managed mine deposits continue to introduce large
quantities of metal contaminants into the river systems, and thus
a robust ecological remediation programme is needed, also
considering that several mining sites have proved to be
economically viable to be re-opened in the near future.
4 th EucheMs chemistry congress
Mining and the Environment – Assessing environmental
impacts
o - 1 5 4
PASt And Current MetAL And MetALLoid
ContAMinAtion froM ABAndoned MininG
SiteS in the SurfACe wAterS of the GArdon
river wAterShed (SoutheAStern frAnCe)
e. reSonGLeS 1 , C. CASiot 1 , r. freydier 1 ,
L. deziLeAu 2 , f. eLBAz-PouLiChet 1 , J. vierS 3
1 Hydrosciences UMR 5569, CNRS Universités Montpellier I
and II IRD, Montpellier, France
2 Géosciences UMR 5243, CNRS Université Montpellier II,
Montpellier, France
3 Géosciences Environnement Toulouse UMR 5563, CNRS
Université Paul Sabatier IRD, Toulouse, France
The Gardon River basin, located in the southeast of the
Massif Central (France), drains many disused mine sites. Metalrich
wastes remaining at these sites represent potential sources of
metals and metalloids to the Gardon River. Besides post-mining
related pollution, current industrial and urban activities may also
contribute to metal enrichment. Considering the important cost of
remediation efforts, it is important to determine the relative
contribution of abandoned mining sites to contaminant loads in a
river system.
In this study, metal and metalloid concentrations were
determined in water (dissolved and particulate phases) and
sediment samples collected during high and low flow conditions
throughout the Gardon watershed. Element concentration ratios
were used to identify the main contaminant sources. Zinc isotopic
composition in suspended particulate matter and sediment
samples was also determined in order to evaluate the possible use
of Zn isotopes as tracers of anthropogenic contaminations in this
context of multiple pollution sources. Current metal
contamination status of the Gardon River was compared to
historical record. For this, metal and metalloid concentration,
element ratios and Zn isotopic composition were determined in
flooding layers of a sediment core sampled on the river bank in
downstream Gardon River.
The sediment core has recorded an increase of metals and
metalloids enrichment from the late 19th century, in association
with the beginning of the industrial era. This core also reveals high
levels of contamination in 1976 related to the breaking of a tailing
dam. Nowadays, some tributaries remain severely impacted by
old mining sites and constitute an important input of contaminants
to the Gardon River mainly during floods. However, other
tributaries impacted by urban and industrial areas are emerging
as significant pollution sources for the Gardon River.
Keywords: Mine-affected river; Metal and metalloid
contamination; Zinc isotopy; Sedimentary archive;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc