PhD opportunities

Source tracing of industrial and urban pollution in the Scarpe River catchment: from mfield work to mass balanced mixing modeling

Thesis proposal

Area of expertiseGeoscience and Geoengineering
Doctoral SchoolGRNE - Gosciences, Ressources Naturelles et Environnement
SupervisorMme Christine FRANKE
Research unitGeosciences
ContactFRANKE Christine
Starting dateOctober 1st 2020
Keywords., .
AbstractRiver systems represent the sink for particles that origin from different sources such as from erosion, precipitation run off, urban or industrial activity as well as water treatment stations. The particulate matter is the transfer vector for anthropogenic pollutants that can be observed in the river sediments/deposits. In the Haute de France Region the hydrographic network is strongly characterized by the navigable waterways, that have to be highly functional and that are managed by VFN (Voies Navigables de France). For the mprovement of the sediment quality and the efficiency of sediment management (e.g. treatment of sewage sludge) a good knowledge of the pollutant sources is necessary, to limit their input and drain.

The sedimentary fraction presents a high spatial heterogeneity in terms of the distribution of the present contaminants, their respective concentrations, the importance and type of their input source. Thus, a delimitation of the input source(s) and a better characterization of the pollutant mixture are needed. In a given river section, the analysis of the contaminant cortege in the context of the suspended particulate matter (SPM) and upstream to downstream sediment deposits presumably result in specific signatures that can be used for finger printing of the different input pathways and sources of pollutants. This approach will also be used to attempt the quantification of
the respective contribution of the sources along the river profile. Statistic methods allow analyzing the spatial variability of concentrations and help to explain observed pollution peaks in sediments taking into account preidentified sources (Alary & Demougeot-Renard, 2009).

The thesis focalizes on the study of polycyclic aromatic hydrocarbon (PAH), polychlorinated biphenyl (PCB), and metal concentrations in the river sediments and on the source tracing of the pollutants in the Scarpe River catchment in northern France, for which a data base is available.

The comprehension on the deposit dynamics and thus the extension of the contaminant mixture and the evolution of the concentrations in respect with the SPM flux and source location will be refined. Sampling campaigns (sediment and SPM) will be conducted to systemize the data set on the cortege of the pollutants and to precise the extension of the mixtures, taking into account the possible concentration variations along the width of the river section. Physico-chemical methods will permit the precision of the link between the hydro-sedimentary processes
and the carrier phases (e.g. Kayvantash et al., 2017; Franke et al., 2009, Franke et al., in rev.).

The concentrations in the sediments will be examined appropriate to their nature and relation to the SPM flux, that are the vectors of the contamination. Multivariate analysis (MVA) of the concentration (in the sediment and SPM) in combination with statistic methods such as mass balanced mixing modeling (Patault et al., 2019) will be applied to the data set to search the tracer signature(s) for the spatial evolution of the signal. Concentration mapping of the pollutants at different spatial scaling and, if possible, an estimation of the level of source contributions will be
established.
ProfileThis multi-disciplinary thesis subject needs a good motivation and operational readiness of the candidate to complete the knowledge in the respective disciplines. The candidate should have a higher university degree
( ingnieur gnraliste , M.Sc. in Geosciences, or equivalent) a solid geochemical and sedimentology training and an interest for physics modeling. The ability for numerical programming are necessary. Skills in geophysics, a strong interest in environmental topics, and a sense for practical field work are highly appreciated. Since the project associates several working groups, a good autonomy and communication skills are expected.
FundingFinancement d'un Etablissement d'enseignement suprieur