Suchergebnisse

Im Runoff-Projekt wurde ein mehrstufiges experimentelles Design verfolgt, das Labortests und Testplot-Experimente einschließt, um das Rückstandsverhalten von Veterinärpharmaka in Gülle und güllegedüngten Böden zu untersuchen. Zusätzlich wurden ökotoxikologische Tests mit terrestrischen und aquatischen Testspezies durchgeführt. Testsubstanzen waren Sulfadiazin, Sulfadimidin, Sulfamethoxazol, Acetyl-Sulfamethoxazol, Flubendazol, Fenbendazol und Ivermectin. Auf der Basis von Stabilitätstests in Gülle, wurde Testgülle mit kurzfristig gealterten Rückständen hergestellt und in Labortests zu Abbau und Sorption in Böden eingesetzt, um bereits hier den realen Eintragspfad durch die Gülleausbringung zu berücksichtigen. In den Testplot-Experimenten wurden die Runoff-Austräge der Testsubstanzen von Acker- und Grünlandflächen nach Gülleausbringung und Intensivberegnung ermittelt. [...] (Quelle: Verf.)

AbstractMicroplastics are the new emerging pollutants ubiquitously detectable in aquatic and terrestrial ecosystems. Fate and behavior, as well as ecotoxicity, are of increasing environmental concern, particularly in sediments and soils as natural sinks. For a global environmental risk assessment, reliable and easy to apply analytical methods are mandatory to obtain comparable data. This is based on the isolation of microplastics out of the solid sample matrices prior to instrumental detection. Thus, this study provides an easy to apply approach for density separation. The technique emerged from a comparative study using different salt solutions to isolate conventional, and for the first time biodegradable, microplastics from different solid sample matrices, i.e., sand, artificial soil, and compost. Four solutions (water, sodium chloride, sodium hexametaphosphate, and sodium bromide) of different densities were applied followed by oxidizing digestion. Finally, the impact of the procedures on size and surface properties of microplastics was tested. Dependent on the sample matrix, the highest recovery rates of 87.3–100.3% for conventional polymers, and 38.2–78.2% for biodegradable polymers, were determined with sodium bromide. It could be shown that the type of solid sample matrix influences the recovery rates and has to be considered when choosing a sample preparation technique.
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AbstractFor a novel approach of resource-efficient water reuse, a municipal wastewater treatment plant was extended at pilot scale for advanced wastewater treatment, i.e., ozonation and biological activated carbon filtration, and a hydroponic system for reclaimed water driven lettuce cultivation. The treatment specific wastewater lines with the corresponding lettuce plants, differentiated into roots and shoots, were monitored for priority wastewater micropollutants, i.e., acesulfame (sweetener), caffeine (stimulant), carbamazepine, diclofenac, ibuprofen, sulfamethoxazole with acetyl-sulfamethoxazole (human pharmaceuticals), 1H-benzotriazole, and 4/5-methylbenzotriazole (industrial chemicals). As clearly demonstrated, conventional tertiary treatment could not efficiently clean up wastewater. Removal efficiencies ranged from 3% for carbamazepine to 100% for ibuprofen. The resulting pollution of the hydroponic water lines led to the accumulation of acesulfame, carbamazepine, and diclofenac in lettuce root systems at 32.0, 69.5, and 135 μg kg−1 and in the uptake of acesulfame and carbamazepine into lettuce shoots at 23.4 and 120 μg kg−1 dry weight, respectively. In contrast, both advanced treatment technologies when operating under optimized conditions achieved removal efficiencies of > 90% also for persistent micropollutants. Minimizing the pollution of reclaimed water thus met one relevant need for hydroponic lettuce cultivation.
Graphical abstract