Encadrement

François Bordas et Alexandra Courtin-Nomade

Context

The research is focused on contaminated sediments from a dam reservoir located downstream of a former mining area. The processing of lead and silver has resulted in increased concentration of risk metals in the sediments. Therefore, representative samples have been collected from different sites of the dam to be characterised from chemical and mineralogical points of view. The main objective is to investigate the mobility of metals and assess the potential risks of contamination for water reservoirs.

Methods

As a first step, the bulk chemical composition and the mineralogy of the sediments will be determined. The following aspects will be mainly addressed:

• chemical speciation of metals based on sequential extraction method,
• solid speciation of metals based on instrumental methods for mineral characterisation such as XRD, SEM, TEM or Raman spectroscopy.

The sediments will be subjected to various laboratory experiments in order to evaluate the stability of the material under different experimental and/or environmental conditions. The basic leaching behaviour of the sediments will be assessed according to standardised procedures, namely Toxicity Characteristic Leaching Procedure (TCLP) and EN 12457 protocols.

Moreover, the effect of several key-controlling parameters on the remobilisation of metals will be investigated including solid/liquid ratio, pH and Eh using laboratory batch experiments. The results will provide essential information for evaluation of the potential mobility of contaminants.

Contact

Martina Vitkova

vitkovam@fzp.czu.cz

  SEM image of sediment particles.