Salome Julia Laake
The continuous accumulation of micropollutants in water is a growing problem for our water resources. Currently, most conventional wastewater treatment plants (WWTP) are not able to remove them efficiently. Several pharmaceuticals, for which the measured concentrations in German surface water might have an effect on some living organisms, are included in this pollutant class, as for example sulfamethoxazole (SMX), carbamazepine (CBZ) and diclofenac (DFC). Phytoremediation is known as an emerging and advantageous technique for soil and water remediation. The potential of using horseradish hairy root cultures (HR) as a plant model for the study of SMX phytoremediation has already been pointed out in a previous work and was tested again in this work, with the addition of a temporal scale (1, 2 and 6 days of contamination). The experiment confirmed the potential of using horseradish HR for SMX phytoremediation, with a disappearance rate from the medium around 90% already after 1 day and close to 100% after 6 days. A novel metabolite (SMX-Glycoside) was also detected in the medium as well as in the HR (concentration measurement with LCMS). Moreover, an enhancement of detoxifying enzymes and no enzymatic stress symptoms could be observed (enzymatic activity measurements with a spectrophotometer). Given that, in real life, SMX is not the only pharmaceutical present in WWTP influents, a second experiment was carried out with a mix contamination (SMX, CBZ and DFC). Although some differences of the SMX fate and of the enzymatic activity were observed, the potential for SMX phytoremediation could be confirmed also in this case (disappearance rate higher than 80% after 1 day and close to 100% after 6 days). DFC was also taken up and metabolized in the analyzed time period, whereas a lower disappearance rate was observed for CBZ. This experiment permitted thus to confirm the potential of using horseradish HR for SMX phytoremediation and to extend it also to a mix contamination (SMX and DFC).