Partner und Internationale Organisationen
(Englisch)
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A, B, BG, CY, CZ, DK, FIN, F, D, GR, H, IRL, IL, I, NL, N, PL, P, RO, SK, SI, E, S, CH, GB
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Abstract
(Englisch)
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Sulphonated aromatic compounds are still largely released in the effluents of dye and textile industry, because of inappropriate wastewater treatments. The present study is a first approach towards the development of a phytotreatment of effluents contaminated with these recalcitrant chemicals using higher plants, especially Rheum (rhubarb) and Rumex. These plants produce natural anthraquinones and were thought to be able to remove sulphonated aromatic pollutants from industrial wastewater. The goals of the present project were thus: · To know if rhubarb plants as well as other anthraquinone producing or non-producing plants were able to accumulate and transform sulphonated anthraquinones. · To perform a small scale study to evaluate the feasibility of a phytotreatment for textile and dye industrial wastewater. · To characterize the mechanisms leading to the accumulation, transformation and/or degradation of sulphonated anthraquinones in whole plants. To achieve this project, an analytical method was developed to analyse simultaneously the five sulphonated anthraquinones, as well as metabolites derived from them, by capillary electrophoresis. All plant species under investigation were successfully adapted to hydroponic culture, chosen as model conditions for this study. The evaluation of the phytotreatment potential shows that rhubarb and related species were much more efficient to remove sulphonated anthraquinones from model effluents than maize or celery (anthraquinone non-producing species). The uptake of sulphonated anthraquinones and their translocation to the shoots was demonstrated in all plants tested. Phytotransformation of these xenobiotics was also likely to occur in all tested species. The direct injection of sulphonated anthraquinones in the shoots of maize and rhubarb did not allow the retrieval of the same metabolites as in the whole plant, indicating that their metabolism probably took place in the roots of the different plants or needed the presence of the roots, even if the participation of the rhizosphere could not be totally excluded. In order to determine if sulphonated anthraquinones might be transformed by an enzyme of the classical detoxification pathways, enzymatic investigations were performed. However, glutathione S-transferases from the leaves of three tested species did not show any activity with the five chemicals under investigation. Finally, the partitioning of one of the sulphonated anthraquinones inside rhubarb leaves was investigated. The results strongly suggest that the xenobiotic was not accumulated as is in the vacuole, but is rather partitioned between the cytoplasm and the cell wall (apoplast). On the basis of the promising results obtained with Rheum and Rumex genera, pilot-studies should be performed. The enzymatic pathways, either classical detoxification or specific to anthraquinone producing plants, leading to the metabolism of sulphonated anthraquinones in the plants should also be investigated.
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