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151.
152.
Carsten Vogt Albin Alfreider Helmut Lorbeer Joerg Ahlheim Bernd Feist Olaf Boehme Holger Weiss Wolfgang Babel Lothar Wuensche 《Water, Air, & Soil Pollution: Focus》2002,2(3):161-170
The SAFIRA in situ pilot plant in Bitterfeld, Saxonia-Anhalt, Germany, currently serves as the test site for eight different in situ approaches to remediate anoxic chlorobenzene (CB)-contaminated ground water. Two reactors, both filled with originallignite-containing aquifer material, are designed for themicrobiological in situ remediation of the ground water bythe indigenous microbial consortia. In this study, thehydrogeological, chemical and microbiological conditions of theinflowing ground water and reactor filling material are presented,in order to establish the scientific basis for the start of thebioremediation process itself. The reactors were put intooperation in June 1999. In the following, inflow CB concentrationsin the ground water varied between 22 and 33 mg L-1; achemical steady state for CB in both reactors was reachedafter 210 till 260 days operation time. The sediments werecolonized by high numbers of aerobic, iron-reducing anddenitrifying bacteria, as determined after 244 and 285 days ofoperation time. Furthermore, aerobic CB-degrading bacteria weredetected in all reactor zones. Comparative sequence analysis of16S rDNA gene clone libraries suggest the dominance of Proteobacteria (Comamonadaceae, Alcaligenaceae, Gallionella group, Acidithiobacillus) and members of theclass of low G+C gram-positive bacteria in the reactorsediments. In the inflowing ground water, sequences withphylogenetic affiliation to sulfate-reducing bacteria andsequences not affiliated with the known phyla of Bacteria, were found. 相似文献
153.
Helmut Karl 《Environmental management》1994,18(4):617-621
environmental auditing must be rejected if the aim is to make companies introduce a specific management concept. Rather, it
is preferable to leave the search for effective environmental protection strategies to the competitive system, especially
since the criteria for environment-oriented management in the European Community audit proposal are without substance. Environmental
auditing can, however, assume a complementary function in the framework of an overall environmental policy if it is designed
as an information tool with which companies provide information on the development of environmental problems deriving from
their manufacturing processes and products. However, the model required to establish a framework of quantity and evaluation
criteria is not available. Further, auditing does not cover products. Similarly, there are no proposals defining the evaluation
procedure for ecological resource scarcity. Thus, the attempt of the Commission of the European Communities to create the
elementary prerequisites for consistent and verifiable environmental auditing in the corporate sector has failed. 相似文献
154.
Infrared (IR) receptors are so far known only in boid and crotalid snakes and in three genera of pyrophilous beetles that seek out forest fires. Pyrophilous insects can also be found in other orders, however, so it can be hypothesised that IR receptors also occur in some of these species. We investigated the pyrophilous Australian flat bug Aradus albicornis and found a small number of dome-shaped sensilla (diameter 13 microm) on the prothorax, which have previously not been described. Ultrastructural investigations revealed that the sensilla are characterised by a fluid-filled inner compartment enclosed in a round cuticular shell. The cuticular apparatus is innervated by the dendrite of a ciliary mechanoreceptor, which is fluidically coupled to the inner compartment. Electrophysiological recordings demonstrated that the sensilla respond to brief warming by red laser light or to broadband IR radiation. Depending on the radiation intensity (4.4-549 mW/cm(2) tested, threshold measured as 11.3 mW/cm(2)), first spike latencies varied between 3.4 and 7.5 ms. Thus, our findings demonstrate that A. albicornis most probably possesses photomechanic IR sensilla resembling the metathoracic IR sensilla of buprestid beetles of the genus Melanophila. In the Melanophila sensillum, IR radiation causes thermal expansion of a fluid, which rapidly deforms the dendritic membrane of a mechanosensory cell. The existence of photomechanic IR receptors in both beetles and bugs demonstrates a remarkable convergent evolution towards this particular biophysical transduction mechanism and suggests that it provides selective advantages over other possible solutions. 相似文献
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Klaus-Michael Wollin Helmut Höring Hermann H. Dieter 《Environmental Sciences Europe》1996,8(5):261-266
Risk assessment of contaminated sites from abandoned ammunition plants follows a multi-stage procedure with its own specific requirements for the toxicological assessment of chemical contaminants. Thus, the 22 explosives and related compounds (STVs) were classified according to carcinogenicity, genotoxicity and evaluation numbers for their toxicological potential (ENs). These characteristics permit a specific toxicological assessment and ranking at the stage of “historical reconnaissance”, independent of an evaluation of the contaminant concentrations. With a view to “orientative site evaluation” for the assessment of explosives and related compounds in groundwater and drinking water, toxicologically related guide values based on the ENs of toxicological potential as well as TDI-based guide values for STVs in soil were derived as based on toxicologically safe body doses and lifelong exposure (TDI=Tolerable Daily Intake). For regulatory purposes, substance related precautionary values are defined for probable carcinogens and contaminants with essential lacks in the toxicological data base. 相似文献
157.
Jürgen Maguhn Helmut Selinger Alexander Ziegler-Jöns Dietmar Knoppik 《Environmental Sciences Europe》1994,6(3):123-130
The effect of short-time fumigation with the peroxidic photooxidants ozone, peroxyacetyl nitrate (PAN), and hydrogen peroxide (H2O2) on the gas exchange of wheat leaves was investigated. Two types of experiments are to be distinguished:
- Fumigation is carried out at atmospheric CO2 partial pressure (350 μbar) and the assimilation and transpiration rates are followed simultaneously.
- The alteration of CO2-response curves by fumigation is determined; from this, characteristic photosynthetic parameters can be calculated.
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