Ph. D. Paul BOIS

Development of a treatment system to decontaminate herbicide polluted vineyard matrices using bioaugmentation together with phytoremediation: selection of a bacteria – sorbent – plant triplet and test in microcosm experiments

Thesis defended in May 2010

Under the direction of Thierry LEBEAU

Abstract

This study aims at developing a depollution system for vineyard sediments and passing water. Glyphosate, diuron and 3,4-dichloroaniline (3,4-DCA) have been chosen, taking a copper load into account. Strategical choices are increased pollutant hydraulic retention time and the use of bioaugmentation together with phytoextraction. Each item on this « sorbent-bacterial inoculum-plant » triplet has been beforehand selected in the laboratory and implemented in microcosm experiments under semi-controlled sorbent material conditions selection in different liquid matrices with pollutants alone or in combination shows that material sorption capacities change with the type of pollutant. It has also been shown that these capacities vary with formulation (alone or in combination) and liquid matrix chosen. Sediment is awarded the best sorbent for glyphosate, sand the best sorbent for diuron and 3,4-DCA.Dissipation performances from isolated colonies are strongly related to the nature of the compound. Elected consortium degrades glyphosate, diuron and 3,4-dichloroaniline (3,4-DCA) in liquid culture as well as it complexes copper microcosm experiments show that hydraulic retention time weighs on pollutant concentration in water at the system outlet. Sorbents prove to be efficient. Dissipation performances are satisfactory. Bio augmentation does not impact on glyphosate and 3,4-DCA dissipation performances significantly, but enhances diuron dissipation in average. Suitable process efficiency requires increased action time within the solid matrix.