3.4 Contribution of EfDOM from Seine-Aval WWTP to the Copper-Binding Site Flux
in the Seine River Downstream of Paris . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
3.5 Modelling of Trace Metal Speciation in the Seine River Upstream and Downstream
of the Paris Conurbation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
3.6 Evaluation of the Role of DOM on Copper Bioavailability Toxicity to Daphnia
magna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
3.7 Effect of EfDOM on Trace Metal Sorption by Mineral Particles in Aquatic Systems
Subjected to Strong Urban Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
3.8 Effect of EfDOM on PAH Adsorption by Mineral Particles in Aquatic Systems
Subjected to Strong Urban Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
4 Conclusions and Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Abstract This research has been conducted over the last 10 years to characterise
the spatio-temporal variability of aquatic organic matter (OM) composition in the
Seine River watershed upstream and downstream of Paris Megacity and its effect
on micro-pollutants. For this purpose, a large number of samples were collected
under different hydrological conditions, and, over 1 year, three representative
sites were monitored monthly. Furthermore, the evolution of the OM composition
along an urbanisation gradient, from upstream to downstream of the Paris agglomeration, was characterised, highlighting the very strong impact of urban discharges,
especially during low-water periods. Substantial differences in the chemical composition are emphasised relative to the urban or natural origin of the organic matter.
Dissolved organic matter (DOM) interactions with metallic and organic micropollutants were studied, allowing us to (1) identify the key role of DOM on their
speciation and bioavailability in aquatic systems and (2) demonstrate that these
interactions depend on DOM composition and origin. The essential role of urban
DOM on the speciation of trace metals in the Seine River downstream of the
Paris agglomeration is also shown.
Keywords Adsorption, Complexation, Dissolved organic matter, EEM
fluorescence spectroscopy, eLTER, Monitoring campaigns, PAHs, Particulate
organic matter, PIREN-Seine, Snapshot campaigns, Trace metals, Water, Zone
Atelier Seine
1 Introduction
In freshwater environments, organic matter (OM), including particulate (POM)
and dissolved (DOM) forms, is a highly complex and dynamic mixture of organic
compounds derived from both natural sources and anthropogenic inputs [1–3]. The
allochthonous (terrestrial plant detritus and soils) or autochthonous (in situ aquatic
production) origin of natural organic matter (NOM) determines its composition and
properties driving microbial processing, carbon cycling and its reactivity in aquatic
ecosystems [4, 5]. NOM is mainly formed by biogeochemical processes such as
photosynthesis, excretion or secretion by organisms, biomass decay or diagenesis
[1]. The concentration and composition of both DOM, including colloidal OM, and
218
G. Varrault et al.
in the Seine River Downstream of Paris . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
3.5 Modelling of Trace Metal Speciation in the Seine River Upstream and Downstream
of the Paris Conurbation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
3.6 Evaluation of the Role of DOM on Copper Bioavailability Toxicity to Daphnia
magna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
3.7 Effect of EfDOM on Trace Metal Sorption by Mineral Particles in Aquatic Systems
Subjected to Strong Urban Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
3.8 Effect of EfDOM on PAH Adsorption by Mineral Particles in Aquatic Systems
Subjected to Strong Urban Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
4 Conclusions and Perspectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Abstract This research has been conducted over the last 10 years to characterise
the spatio-temporal variability of aquatic organic matter (OM) composition in the
Seine River watershed upstream and downstream of Paris Megacity and its effect
on micro-pollutants. For this purpose, a large number of samples were collected
under different hydrological conditions, and, over 1 year, three representative
sites were monitored monthly. Furthermore, the evolution of the OM composition
along an urbanisation gradient, from upstream to downstream of the Paris agglomeration, was characterised, highlighting the very strong impact of urban discharges,
especially during low-water periods. Substantial differences in the chemical composition are emphasised relative to the urban or natural origin of the organic matter.
Dissolved organic matter (DOM) interactions with metallic and organic micropollutants were studied, allowing us to (1) identify the key role of DOM on their
speciation and bioavailability in aquatic systems and (2) demonstrate that these
interactions depend on DOM composition and origin. The essential role of urban
DOM on the speciation of trace metals in the Seine River downstream of the
Paris agglomeration is also shown.
Keywords Adsorption, Complexation, Dissolved organic matter, EEM
fluorescence spectroscopy, eLTER, Monitoring campaigns, PAHs, Particulate
organic matter, PIREN-Seine, Snapshot campaigns, Trace metals, Water, Zone
Atelier Seine
1 Introduction
In freshwater environments, organic matter (OM), including particulate (POM)
and dissolved (DOM) forms, is a highly complex and dynamic mixture of organic
compounds derived from both natural sources and anthropogenic inputs [1–3]. The
allochthonous (terrestrial plant detritus and soils) or autochthonous (in situ aquatic
production) origin of natural organic matter (NOM) determines its composition and
properties driving microbial processing, carbon cycling and its reactivity in aquatic
ecosystems [4, 5]. NOM is mainly formed by biogeochemical processes such as
photosynthesis, excretion or secretion by organisms, biomass decay or diagenesis
[1]. The concentration and composition of both DOM, including colloidal OM, and
218
G. Varrault et al.