Erprobung und Erfolgskontrolle eines Phytoremediations-verfahrens zur Sanierung Sprengstoff-kontaminierter B?den

Zusammenfassung  Die Befunde des in seiner Konzeption in Teil I dargestellten Freilandexperimentes dokumentieren die TNT-Abreicherung und Erholung des Standortes im Laufe der Phytoremediation. Das Monitoring umfasst Erhebungen im Feld (Nitroaromatengehalte in Boden, Sickerwasser und Pflanzen; Erfassung von Bodenorganismen und Streuabbau) und den Einsatz einer Biotestbatterie mit 6 Einzeltests. Die Daten belegen die hohe Heterogenit?t der TNT-Kontamination, eine rasche initiale Abreicherung und eine geringe Verlagerung von Nitroaromaten in Pflanzen und Sickerwasser. Die anf?nglich rasche Transformation des TNT zu Aminodinitrotoluolen l?sst nach 3 Monaten deutlich nach. Mit Hilfe der Biotestbatterie wird die Toxizit?t des Bodens differenziert beurteilbar; die boden-biologischen Befunde lassen Langzeitwirkungen der TNT-Belastung wahrscheinlich werden. Eine Gesamtbeurteilung des Projekts wird im dritten Teil der Artikelserie erfolgen. OnlineFirst: 10. 09. 2001     

Idiothetic orientation of a wandering spider: Compensation of detours and estimates of goal distance

Summary The wandering spider Cupiennius salei Keys uses idiothetic orientation, i.e., memorized information about its own previous movements, to retrieve lost prey. Spiders, having been chased away from a prey fly, return to the capture site (the goal) over a distance of more than 75 cm even though all external orientation cues were precluded. This behavior and its sensory basis were examined by varying the proprioceptive and motor command inputs to the memory and by ablating particular lyriform slit sense organs on the legs of the spider.The success rate of returns to the goal after rectilinear chases over 6 discrete distances ranging from 20 cm to>41 cm declines with increasing distances. At distances>41 cm, more than 50% of the performances of intact spiders are nevertheless successful, in that the animals approach the capture site as close as 5 cm (or less).Animals that have been operated on (lyriform organs on all femora destroyed) are much less successful even at short distances. The mean starting angles of the returns by intact spiders and by those operated on do not differ signficantly. Walking error e _n for each segment of the entire return path shows that intact animals deviate little from the ideal return route and correctly estimate the distance to the goal. The operated spiders tend to drift off the ideal return route, while their distance estimates remain largely accurate.Returns after curvilinear chases through a semicircular corridor do not retrace the curved path; instead the spiders take a shortcut. Of all performances by intact and by control spiders (with sham operations) 85% are successful. By contrast, most of the 8 groups with sensory ablations have a success rate of less than 50%.Compensation for the semicircular detours is not quite complete: the mean starting directions of returns are biased, pointing to the corridor, and the shape of many return paths reflects the curved corridor shape. Spiders with unilateral ablations of their femoral lyriform organs show low success rates only if the operated legs are on the inner curve perimeter during the chase, while their return parameters resemble those of the intact group in the reverse situation (operated legs on outer perimeter). These side-specific ablation effects, which are correlated with the geometrical situation existing while idiothetic information is gathered and memorized, suggest that the idiothetic memory depends at least partly on input from proprioceptors.     

Impact of photocatalytic remediation of pollutants on urban air quality

In the recent years, photocatalytic self-cleaning and “depolluting” materials have been suggested as a remediation technology mainly for NO _x and aromatic VOCs in urban areas. A number of products incorporating the aforementioned technology have been made commercially available with the aim to improve urban air quality. These commercial products are based on the photocatalytic properties of a thin layer of TiO₂ at the surface of the material (such as glass, pavement, etc.) or embedded in paints or concrete. The use of TiO₂ photocatalysts as an emerging air pollution control technology has been reported in many locations worldwide. However, up to now, the effectiveness measured in situ and the expected positive impact on air quality of this relatively new technology has only been demonstrated in a limited manner. Assessing and demonstrating the effectiveness of these depolluting techniques in real scale applications aims to create a real added value, in terms of policy making (i.e., implementing air quality strategies) and economics (by providing a demonstration of the actual performance of a new technique).

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Perfluorooctanoic acid and perfluorooctane sulfonate released from a waste water treatment plant in Bavaria, Germany

Purpose

Perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and precursors and derivatives thereof have been employed as surfactants and anti-adhesives. PFOA and PFOS are environmentally persistent and the discharge of municipal waste waters is one of the principal routes of these compounds into the aquatic environment. In a previous study, the concentrations of PFOA and PFOS in grab samples collected from the waste water treatment plant (WWTP) of Bayreuth, a city of 72,000 inhabitants in Bavaria, Germany, during two periods showed considerable variability. For a better estimate of average mass flows, the surfactants were monitored (five samplings) from 16 March to 18 May 2007. In a second campaign, river water receiving the WWTP effluent was sampled twice a day for five consecutive days.

Methods

Quantitative analysis was done by stable-isotope dilution, pre-cleaning, and pre-concentration by solid-phase extraction, and liquid chromatography followed by electrospray ionization/tandem mass spectrometry.

Results

The mass flows of PFOA and PFOS through the WWTP were determined. PFOA is fully discharged into the river, while about half of PFOS is retained in the sewage sludge. The average daily mass load of the river Roter Main by the WWTP of Bayreuth is about 1.2?±?0.5 g PFOA and 5?±?2 g PFOS, with variations of up to 140% within one day.

Conclusion

Overall, the total annual release to the rivers of Germany may be in the range of several hundred kilograms of PFOA and several tons of PFOS.     

Bleiverunreinigung von trinkwasser durch leitungssysteme in Berlin

There are many acute and chronic adverse effects of lead on human beings. This is especially true for infants and children. In Germany, the intake of lead through drinking water is commonly due to metal corrosion of the user’s plumbing. In the last years and decades, many lead pipes in Germany were replaced by pipes made of alternative materials. The aim of this study was to assess the present state of drinking water contamination and the resulting lead exposure in infants, the most sensitive population group. For this purpose, mothers of newborn babies were offered a free examination of their drinking water. After a written declaration of consent had been received, two composite samples collected during the day were obtained from the families. The samples were analyzed for their lead concentration using atomic absorption spectrometry. A total of 2109 samples from house holds in the area of Berlin, Germany were collected. From the first composite samples 5.6% and 7.0% of the second composite samples demonstrated lead concentrations higher than 0.01 mg/l (recommended limit of the WHO). 0.95% of the first composite samples and 1.3% of the second composite samples had concentrations above the limit of the German drinking water regulation (0.04 mg/l). The highest measured lead concentrations is the first and second composite samples were 0.19 and 0.13 mg/l, respectively. By region, the suburbs of Charlottenburg, Neukölln, Schöneberg, Wilmersdorf and Zehlendorf were particularly severley affected with more than 10% and their samples being elevated above 0.01 mg/l.     

Perfluorooctanoic acid and perfluorooctane sulfonate in the sediment of the Roter Main river, Bayreuth, Germany

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are widely distributed in aquatic ecosystems. Their sources are known but few studies about their accumulation potential in river sediments exist. The aim of this study is to assess the concentrations of PFOA and PFOS in sediments in relation to their levels in river water receiving effluent from a waste water treatment plant (WWTP). PFOS accumulates by a factor of about 40 relative to river water, PFOA only up to threefold. In contrast to previous suggestions, in this case the enrichment on sediment is not correlated to the total organic carbon contents.     

Pesticide fate in tropical wetlands of Brazil: an aquatic microcosm study under semi-field conditions

A contamination of off-site aquatic environments with pesticides has been observed in the tropics, yet only sparse information exists about pesticide fate in such ecosystems. The objective of our semi-field study was to elucidate the fate of alachlor, atrazine, chlorpyrifos, endosulfan, metolachlor, profenofos, simazine, and trifluralin in the aqueous environment of the Pantanal wetland (MT, Brazil). To this aim, water and water/sediment microcosms of two sizes (0.78 and 202 l) were installed in the outskirts of this freshwater lagoon environment and pesticide dissipation was monitored for up to 50 d after application. The physical-chemical water conditions that developed in the microcosms were reproducible among field replicates for both system sizes. Pesticide dissipation was substantially enhanced for most pesticides in small microcosms relative to the large ones (reduced DT(50) by a factor of up to 5.3). The presence of sediment in microcosms led to increased persistence of chlorpyrifos, endosulfan, and trifluralin in the test systems, while for polar pesticides (alachlor, atrazine, metolachlor, profenofos, and simazine) a lesser persistence was observed. Atrazine, simazine, metolachlor, and alachlor were identified as the most persistent pesticides in large water microcosms (DT(50) > or = 47 d); in large water/sediment systems endosulfan beta, atrazine, metolachlor, and simazine showed the slowest dissipation (DT(50) > or = 44 d). A medium-term accumulation in the sediment of tropical ecosystems can be expected for chlorpyrifos and endosulfan isomers (11-35% of applied amount still extractable at 50 d after application). We conclude that the persistence of the studied pesticides in aquatic ecosystems of the tropics is not substantially lower than during summer in temperate regions.