Fractionation of trace metals in a contaminated freshwater stream using membrane filtration, ultrafiltration, DGT and transplanted
aquatic moss
Björn Öhlander
Jerry Forsberg
Heléne Österlund
Johan Ingri
Frauke Ecke
Lena Alakangas
10.6084/m9.figshare.3453173.v1
https://geolsoc.figshare.com/articles/journal_contribution/Fractionation_of_trace_metals_in_a_contaminated_freshwater_stream_using_membrane_filtration_ultrafiltration_DGT_and_transplanted___aquatic_moss/3453173
<p>Four metal speciation and fractionation techniques – DGT (diffusive gradients in thin films), 1-kDa ultrafiltration, 0.22-µm
membrane filtration and aquatic moss – were simultaneously applied to a small, contaminated freshwater stream in northern
Sweden to investigate differences and similarities between the methods regarding trace metal speciation and their dependence
on geochemical water properties. The investigated metals comprise Al, Cd, Co, Cu, Fe, Mn, Ni, and Zn. The normal DGT devices
with Chelex cation exchanger were used. Shoots from the aquatic moss <em>Fontinalis antipyretica</em> L ex Hedw. were collected in a non-polluted brook and transplanted to the sampling site for exposure. It was evident that
0.22-µm membrane filtration, 1-kDa ultrafiltration and DGT generally measured different metal fractions where <1-kDa ultrafiltered
concentrations were lower than DGT labile concentrations which in turn were lower than <0.22-µm concentrations. The differences
between DGT and <1-kDa concentrations indicate the occurrence of labile colloids discriminated by ultrafiltration. Strong
correlations between DGT and <1 kDa concentrations were found for Al, Cu, Cd, Co and Zn. Despite a rigorous sample cleaning,
retention of particulate matter on the moss samples was revealed by a significant correlation between metal concentrations
in moss and particulate Fe. Generally, elevated trace metal concentrations were found in moss exposed at the sampling site
compared to reference moss from the non-polluted brook. No significant correlations were found between DGT-labile concentrations
and moss concentrations.
</p>
2016-06-21 11:11:40
Chelex cation exchanger
lt
geochemical water properties
trace metal concentrations
ultrafiltration
DGT
moss Fontinalis antipyretica L
sampling site
trace metal speciation
Geology