Phytomanagement - Tavaux (F-39)

The site is located in Western Europe along a major river and surrounded by several urban aggregates. Production at the chlor- alkali facility began in 1950 with wastewater discharged directly to a stream. In 1964 a dam was constructed downstream of the discharge. A 12-ha area with dikes 5-m high was constructed adjacent to the mitigation pond for disposal of the sediment removed by a hydraulic dredge. Wastewater treatment at the plant facility was installed in 1987, which reduced Hg concentrations in sediments settling in the mitigation pond. Chlorine production at the facility was eventually converted to a non-Hg technology in 2004 and the disposal area, now known as the landfill, ceased receiving sediments the same year. At this site several projects have been implemented:
- to investigate the historical evolution of Hg concentrations in tree rings from trees growing on and near the landfill that received dredged sediments from the Hg cell chlor-alkali facility. The objective was also to determine whether the sediments are currently a source of Hg emissions
- to delineate subsurface CE contamination using phytoscreening within the research and development project SILPHES-ADEME,
- to study the relative abundance and composition of microbial groups across poplar habitats that may improve our understanding of the microbial ecology of these environments (FREIDI-Hg CNRS and BIOFILTREE-ANR)
- to study Hg uptake and biomagnification through an original and specific soil -plant- terrestrial insect system in a Hg-contaminated area in France and to estimate the extent to which insect-related factors affected Hg uptake
- to investigate the potentialities of nettle fibres growing spontaneously under poplar for material application (ERA-NET NETFIB and ADEME-PHYTOFIBER).