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.     

Geoelectrical methods for monitoring geological CO2 storage: First results from cross-hole and surface–downhole measurements from the CO2SINK test site at Ketzin (Germany)

The feasibility of monitoring CO₂ migration in a saline aquifer at a depth of about 650 m with cross-hole and surface–downhole electrical resistivity tomography (ERT) is investigated at the CO₂SINK test site close to Ketzin (Germany). The permanent vertical electrical resistivity array (VERA) consists of 45 electrodes (15 in the injection well Ktzi201 and 15 in each of the two observation wells Ktzi200 and Ktzi202), successfully placed on the electrically insulated casings, in the depth range of about 590–740 m with a spacing of about 10 m. The three Ketzin wells are arranged as perpendicular triangle with distances of 50 and 100 m.First synthetic modelling studies indicate an increase of the electrical resistivity of about 200% caused by CO₂ injection, corresponding to a bulk CO₂ saturation of 50%, which is in good agreement with laboratory studies. Finite difference inversion of field data delivers three-dimensional resistivity distributions between the wells which are consistent with the reservoir modelling studies.To increase the limited observation area provided by the cross-hole measurements, additional surface–downhole measurements were deployed. A main CO₂ migration in SE–NW direction is deduced from surface to downhole resistivity experiments.The first cross-hole time-lapse results show that the resolution and the coverage of the electrode array in the Ketzin setting are sufficient to resolve the expected resistivity changes on the characteristic length scale of the electrode array. Significant resistivity changes could be measured, however, detailed information on the CO₂ plume could not be resolved yet by VERA under the existing geological circumstances.     

Erprobung und Erfolgskontrolle eines Phytoremediations-verfahrens zur Sanierung Sprengstoff-kontaminierter Böden

Results of a field experiment (please refer to Warrelmann et al. 2000a) document TNT-degradation and regeneration after the establishment of a phytoremediation. Various approaches are included in a complex monitoring system, which are conducted in the field (nitroaromatics in soil, seepage water, and plants; soil fauna; soil fungi; decomposition) as well as in the lab (a battery of 6 biotests). The data document a high heterogeneity of the TNT-contamination, a rapid initial decrease and a mediocre displacement of nitroaromatics in plants and seepage water. The initial rapid transformation of TNT to aminodinitrotoluenes ceases significantly after 3 months. Results of the biotest battery allow a sophisticated assessment of soil toxicity; the results from the soil ecological field investigations make the long-term effects of TNT-contamination likely. In a third part of the series of articles, a synopsis and judgement of the project will be delivered.     

Validation of spectral gas radiation models under oxyfuel conditions—Part B: Natural gas flame experiments

Combustion of hydrocarbon fuels with pure oxygen results in a different flue gas composition as combustion with air. Standard CFD spectral gas radiation models for air blown combustion are out of their validity range. The series of three articles provides a common spectral basis for the validation of new developed models. Part B of the series presents spectral measurements in the spectral range of 2.4–5.4 μm of a 70 kW turbulent natural gas flame in air blown combustion and in wet and dry oxyfuel combustion. The experimentally measured intensity spectra were compared with simulated spectra based on measured gas atmospheres. The line-by-line database HITEMP2010 and the two statistical-narrow-band models EM2C and RADCAL were used for the numerical simulation. The measured spectra showed large fluctuations due to turbulence. The up to 75% increased averaged experimental intensity compared to the simulated intensity pointed out the importance of the effect of turbulence-radiation-interaction in combustion simulations.     

Description and evaluation of a sampling system for long-time monitoring of PAHs wet deposition

In this paper a new electronically controlled year-round wet-only sampler for wet deposition of trace organic compounds (e.g. airborne PAHs) is described. The sampler provides in situ filtration of the precipitation as well as preconcentration of nonpolar organic compounds by means of a C18-PAH modified silica gel cartridge. The whole assembly is insulated and equipped with heating elements which permit collection of wet deposition as ice or snow and insure correct function of the sampling system even during cold weather. Concurrent chemical analysis of both the particulate and the dissolved phases is performed by high resolution gas chromatography with flame ionization detection or HPLC with fluorescence detection. The reliability of the method was proved by analyzing PAH spiked water (simulated rain) and using NIST SRM 1649 ('urban dust') as certified material for particle-bound PAHs in precipitation. This study proved satisfactorily recoveries of as both particle-bound and unbound aqueous PAH, with only small losses to collector surfaces. It was proved that this new wet-only precipitation sampler can successfully be used for long-time monitoring of PAH in wet depositions in urban areas.     

Schadstoffbelastung von Stra?enkehricht und Sedimenten der Regenwasserkanalisation durch den Stra\enverkehr am Beispiel von G?ttingen

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