Field Studies on the Fate and Transport of Pharmaceutical Residues in Bank Filtration

Bank filtration and artificial ground water recharge are important, effective, and cheap techniques for surface water treatment and removal of microbes, as well as inorganic, and some organic, contaminants. Nevertheless, physical, chemical, and biological processes of the removal of impurities are not understood sufficiently. A research project titled Natural and Artificial Systems for Recharge and Infiltration attempts to provide more clarity in the processes affecting the removal of these contaminants. The project focuses on the fate and transport of selected emerging contaminants during bank filtration at two transects in Berlin, Germany. Several detections of pharmaceutically active compounds (PhACs) in ground water samples from bank filtration sites in Germany led to furthering research on the removal of these compounds during bank filtration. In this study, six PhACs including the analgesic drugs diclofenac and propyphenazone, the antiepileptic drugs carbamazepine and primidone, and the drug metabolites clofibric acid and 1-acetyl-1-methyl-2-dimethyl-oxamoyl-2-phenylhydrazide were found to leach from the contaminated streams and lakes into the ground water. These compounds were also detected at low concentrations in receiving public supply wells. Bank filtration either decreased the concentrations by dilution (e.g., for carbamazepine and primidone) and partial removal (e.g., for diclofenac), or totally removed PhACs (e.g., bezafibrate, indomethacine, antibiotics, and estrogens). Several PhACs, such as carbamazepine and especially primidone, were readily transported during bank filtration. They are thought to be good indicators for evaluating whether surface water is impacted by contamination from municipal sewage effluent or whether contamination associated with sewage effluent can be transported into ground water at ground water recharge sites.     

The significance of fixed ammonium in Palaeozoic sediments for the generation of nitrogen-rich natural gases in the North German Basin

In contrast to predominantly hydrocarbon-rich natural gases in the western part of the Central European Basin (CEB), accumulations of natural gases from the eastern part of the North German Basin (NGB) are nitrogen-rich with up to 90% N₂. This study is focused on the behaviour of fixed ammonium in clay minerals of organic-rich Palaeozoic sediments in the eastern part of the NGB as a major source of nitrogen-rich natural gases. Carboniferous shales have been investigated for a better understanding of nitrogen fixing during diagenesis, storage during burial and release during devolatilization processes or fluid–rock interactions. The total nitrogen contents in the studied Carboniferous shales of the NGB reach up to 2700 ppm with an inorganic fixed portion (in the form of NH₄ ⁺–N) of more than 60%. The results of this study indicate an increasing proportion of the mineralogically fixed ammonium with increasing thermal maturity and storage up to catagenetic conditions. The isotopic composition of fixed-NH₄ is relatively homogeneous in the majority of the shales and ranges from +1 to +3.5‰. In contrast, samples from the basin centre show a significant decrease in ammonium contents down to 460 ppm coupled with a shift in δ¹⁵N up to +5.6‰ suggesting a release of nitrogen on a large scale. Calculation of nitrogen loss and isotopic fractionation indicate that more than 30% of nitrogen was released as ammonium probably as a consequence of fluid-rock interaction with highly saline brines.     

Nitrate temporal and spatial patterns in 12 water-supply wells, Yucatan, Mexico

 The nitrate concentration in 12 water-supply wells were monitored for the period April 1992 to March 1993. Each water-supply well was sampled once a month. The nitrate concentrations in the 12 wells ranged from 7 to 156 mg/l. Two water-supply wells (Chacsinkin and Peto) showed concentrations that reached 3.5 times the maximum permissible limit for the Drinking Water Standard (45 mg/l). A third water-supply well (Akil) exceeds the norm for 7 out of 12 months. The use of nitrogen-rich fertilizers are responsible for high nitrate concentrations in groundwater in the southern part of Yucatan, Mexico where intensive agricultural practices exist. Received: 14 December 1999 · Accepted: 2 May 2000     

A case study of Kelvin-Helmholtz waves within an off-shore stable boundary layer: Observations and linear model

A case study of Kelvin-Helmholtz waves which were observed by two aircraft in a warm off-shore stable boundary-layer flow over the North Sea is presented. During the one-hour flight mission within an area of 40 × 40 km², the waves were intermittent both in space and time. They were centered around two levels, at 90 and 330m, where inflection points in the mean profile of the cross-wave wind component occurred together with Richardson numbers smaller than the critical value of 0.25. Observed wave amplitudes were on the order of 0.1 K for the potential temperature, 0.15ms^-1 for the vertical wind component, 0.3ms^-1 for the cross-wave wind component and 0.15ms^-1 for the along-wave wind component. Horizontally averaged vertical wave transports were down-gradient.Based on the observed wind and temperature profiles, wave simulations with a linear model are performed. Different diffusion coefficient estimates are tested. The model produces two types of Kelvin-Helmholtz waves with maximum amplitudes at the above mentioned two heights. The modeled wavelengths are about 30% shorter than the observed ones. Adjusting the modeled to the observed temperature variations, the modeled vertical wind variance and the vertical transports agree well with the observations, whereas the modeled horizontal wind variances are smaller than the observed ones.     

New insights into lake responses to rapid climate change: the Younger Dryas in Lake Gościąż, central Poland

The sediment profile from Lake Gościąż in central Poland comprises a continuous, seasonally resolved and exceptionally well-preserved archive of the Younger Dryas (YD) climate variation. This provides a unique opportunity for detailed investigation of lake system responses during periods of rapid climate cooling (YD onset) and warming (YD termination). The new varve record of Lake Gościąż presented here spans 1662 years from the late Allerød (AL) to the early Preboreal (PB). Microscopic varve counting provides an independent chronology with a YD duration of 1149+14/–22 years, which confirms previous results of 1140±40 years. We link stable oxygen isotopes and chironomid-based air temperature reconstructions with the response of various geochemical and varve microfacies proxies especially focusing on the onset and termination of the YD. Cooling at the YD onset lasted ~180 years, which is about a century longer than the terminal warming that was completed in ~70 years. During the AL/YD transition, environmental proxy data lagged the onset of cooling by ~90 years and revealed an increase of lake productivity and internal lake re-suspension as well as slightly higher detrital sediment input. In contrast, rapid warming and environmental changes during the YD/PB transition occurred simultaneously. However, initial changes such as declining diatom deposition and detrital input occurred already a few centuries before the rapid warming at the YD/PB transition. These environmental changes likely reflect a gradual increase in summer air temperatures already during the YD. Our data indicate complex and differing environmental responses to the major climate changes related to the YD, which involve different proxy sensitivities and threshold processes.     

Sediment sequences and paleosols in the Kyichu Valley, southern Tibet (China), indicating Late Quaternary environmental changes

Abstract The Tibetan Plateau is highly sensitive to environmental changes and affects the settings of a far larger territory in Central Asia and beyond. Thus, knowledge on past environmental changes in that area is essential. Even though the Kyichu (Lhasa River) Valley and its tributaries is an easily accessible area, the Late Quaternary landscape evolution of southern Tibet is in general scarcely known. Therefore, 12 sedimentary sections in the middle and lower catchment were subjected to multidisciplinary analyses (sedimentology, paleopedology, AMS ¹⁴C and luminescence dating, and charcoal determination) aiming at results on regional paleoenvironmental changes. At the altitude studied (3600–4000 m above sealevel), no glacial relics could be detected, indicating that the valley positions have been unglaciated since the Last Interglacial. The lack of fluvial–lacustrine structures above the floodplain is due to the aggradational character of this tectonically (sub‐)active valley, which caused an alluvial burying of older valley bottoms. During the Late Pleistocene the mouth area of the Kyichu was occupied by a lake which was part of a larger dam‐lake in the superordinate Yarlung Zhangbo Valley. On the valley flanks, loesses were predominantly deposited before the Last Glacial Maximum (LGM), whereas eolian sands were predominantly deposited around and after the LGM. Paleosols of Last Interglacial, Last Glacial and Holocene ages regularly occur at terrestrial sites representing temperate to cool and humid to semiarid conditions during soil formation. Ages of colluvial sediments indicate that the widespread barren valley slopes were primarily formed by Late Pleistocene erosion followed by a secondary Holocene erosion phase. Charcoal spectra indicate a Late Holocene change from a forest environment to a pastoral environment with sparse grasses, herbs and dwarf shrubs. It is assumed that the Late Holocene environmental changes, such as loss of forests/woodlands and erosion, have at least been reinforced by humans, enhancing a regional climatic aridification and cooling trend.     

Climate change impacts on runoff in the Ferghana Valley (Central Asia)

The main freshwater source of arid/semi-arid Central Asia is stored in its high mountain glaciers. Water for the downstream countries is mainly supplied through the Syrdarya River that originates at the confluence of the Naryn and Karadarya rivers in the Ferghana Valley. Runoff generation from glaciers plays a crucial role, although a considerable number of small tributaries supply the river with additional runoff from snowmelt and rain in the mountains surrounding the Ferghana Valley. Observations of rising air temperature and accelerated glacier shrinkage make it most likely that the relative contributions of the smaller tributaries will increase. Hitherto, assessments of climate change effects on the water resource availability have largely neglected the growing importance of the runoff from smaller tributaries. We used a dynamically downscaled A1B SRES scenario for climate change effects for the period 2071–2100 in relation to the reference period of 1971–2000 and a version of the conceptual hydrological Hydrologiska Byråns Vattenavdelning model (HBV-light) to estimate runoff contributions with particular respect to the small tributaries. The simulations showed a 12–42% decrease in summer runoff; and a 44–107% increase in winter-spring runoff. This indicates the hydrological regime is shifting towards a runoff from snowmelt earlier in the year. The study suggests that actions for climate change adaptation should be complemented by land management configured to secure optimal runoff supplement from the smaller catchments.     

Calibration facility for airborne imaging spectrometers

A new facility designed to perform calibration measurements of airborne imaging spectrometers was established at the German Aerospace Center (DLR) in Oberpfaffenhofen. This Calibration Home Base (CHB) is optimized to characterize radiometrically, spectrally, and geometrically the APEX (Airborne Prism Experiment) imaging spectrometer, which is currently being developed under the authority of the European Space Agency (ESA). It however can be used for other optical sensors as well. Computer control of major laboratory equipment allows automation of time consuming measurements. In APEX configuration (wavelength range: 380 to 2500 nm, instantaneous field of view: 0.48 mrad, field of view: ±14) spectral measurements can be performed to a wavelength uncertainty of ±0.15 nm, geometric measurements at increments of 0.0017 mrad across track and 0.0076 mrad along track, and radiometric measurements to an uncertainty of ±3% relative to national standard. The CHB can be adapted to similar sensors (including those with thermal infrared detectors) by exchanging the monochromator’s lamp, the gratings and the filters, and by adjusting the distance between the sensor and folding mirror.     

Remote sensing of terrestrial impact craters: The TanDEM‐X digital elevation model

With the TanDEM‐X digital elevation model (DEM), the terrestrial solid surface is globally mapped with unprecedented accuracy. TanDEM‐X is a German X‐band radar mission whose two identical satellites have been operated in single‐pass interferometer configuration over several years. The acquired data are processed to yield a global DEM with 12 m independent posting and relative vertical accuracies of better than 2 m and 4 m in moderate and mountainous terrain, respectively. This DEM provides new opportunities for space‐borne remote‐sensing studies of the entire sample of terrestrial impact craters. In addition, it represents an interesting repository to aid in the search for new impact crater candidates. We have used the TanDEM‐X DEM to investigate the current set of confirmed impact structures. For a subsample of the craters, including small, midsized, and large structures, we compared the results with those from other DEMs. This quantitative analysis demonstrates the excellent quality of the TanDEM‐X elevation data. Our findings help to estimate what can be gained by using the TanDEM‐X DEM in impact crater studies. They may also be beneficial in identifying the regions and morphologies where the search for currently unknown impact structures might be most promising.