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The world's domestic cats carry patterns of sequence variation in their genome that reflect a history of domestication and breed development. A genetic assessment of 979 domestic cats and their wild progenitors—Felis silvestris silvestris (European wildcat), F. s. lybica (Near Eastern wildcat), F. s. ornata (central Asian wildcat), F. s. cafra (southern African wildcat), and F. s. bieti (Chinese desert cat)—indicated that each wild group represents a distinctive subspecies of Felis silvestris. Further analysis revealed that cats were domesticated in the Near East, probably coincident with agricultural village development in the Fertile Crescent. Domestic cats derive from at least five founders from across this region, whose descendants were transported across the world by human assistance.

The in situ stabilization of old deposits aims for a lasting and controlled reduction of pollutant emissions from the deposited waste in order to diminish expenditure and the duration of landfill aftercare measures. The stabilization operation so far, observed over a period of 1-2 years at three landfills in Germany, shows that leachate contamination is permanently reduced, biodegradation processes are significantly accelerated and main settlements take place within a short period of time.

For the treatment of contaminated sites, securing as well as remediation methods are applied. While remediation achieves decontamination or reduction of pollutants, securing sets up technical barriers for the protection of the environment. Since the source of contamination remains in place and the technical barriers are subject to aging and environmental influences, securing measures often represent only a time restricted solution and future remediation activities become necessary. Remediation methods are classified according to their operation location as well as to processing aspects. Thus, ex situ and in situ processes are available on the one hand, and thermal, chemical, physical, and biological processes on the other. The ex situ processes require excavation of the contaminated soil and soil treatment either at the site (on-site remediation) or at an external soil treatment plant (off-site remediation). In contrast, in situ treatment takes place at the site in the contaminated soil itself, without any soil excavation. Thermal processes are used for the treatment of highly concentrated organic pollutants, but they are suitable only to a small extent for the elimination of heavy metals. With soil scrubbing, the coarse-grain fraction >63 μm is purified, transferring the pollutants into the water phase and/or into the fine-grain fraction. This fine fraction is highly loaded with pollutants and thus has to be treated and disposed of afterwards. The biopile process is applied on a large scale as a state-of-the-art technology. It is an effective process for the treatment of biologically degradable pollutants such as mineral oil and its derivatives, aliphatic hydrocarbons, phenols, formaldehyde, and other soil contaminants. In remediation practice, there is a trend toward actions with a minimum of requirements. Contaminated sites are remediated or secured, depending on the intended after-use, e.g., housing, development of commercial or industrial facilities, or as recreational areas. Depending on the kind of use, specific target values have to be met after treatment. If the contaminated site is not being used and so far no major dangerous contamination of the groundwater, surface water, etc. has occurred, 259

For the set-up of a remediation concept, suitable field simulation pre-tests on a laboratory, as well as on a technical scale, should principally be carried out. The application of test systems and laboratory reactors is also necessary for basic examination and a general understanding of the degradation processes within soils. When conceptualising biological remediation measures the respective laboratory scale pre-tests should be designed in a way, that answers the questions posed concerning the possibility to comply with the respective microbial, physiochemical and process-geological conditions. The most important, but also most difficult, task is the evaluation of the possibility for remediation of soils. Laboratory results about microbial degradation of relevant contaminants in problem sites have to be transferable into practice and consequently provide data about degradation. This includes degradation rates, final concentrations that can be yielded, formed metabolites and end products respectively. They should be selected between different, complex test systems according to the initial question.

Biological treatment of contaminated soil is the most common method of soil treatment during the redevelopment of old sites (ITVA 1997). Biopiles in particular are frequently used due to the simple handling involved and process realisation. The significance of the bioremediation of old sites depends on the reutilisation of the soil material to be treated. The objective should be an increase in the amount of decontaminated soil for ecological and economic reutilisation e.g. as a culture medium in landscape architecture.

In 1989 the research centre “Treatment of Contaminated Soils” was set up by the Deutsche Forschungsgemeinschaft (DFG=German Research Foundation). Within the framework of this special programme the Technical University of Hamburg-Harburg (seat of chair) and the University of Hamburg began to investigate basic methods for the treatment of contaminated soils in 16 projects. The first two research periods ran from Jan. 1st, 1989 up until Dec. 31st, 1994. The third research period will end on the 31st of Dec. 1997.

In 1989 the research center, 'Treatment of Contaminated Soils' was set up by the Deutsche Forschungsgemeinschaft (DFG equals German Research Foundation). Within the framework of this special program the Technical University of Hamburg-Harburg (seat of chair) and the University of Hamburg investigate basic methods for the treatment of contaminated soils in 17 projects. The first research periods ran from Jan. 1, 1989 up until Dec. 31, 1994. The third research period will end on 31 Dec. 1997. It is the aim of the research center not just to investigate, develop and optimize decontamination methods but simultaneously to perfect both analytical and measuring techniques thus enabling the swift and comprehensive description of all processes. The primary objective of all projects within the SFB 188 is the clarification and description of mechanisms which either result in decontamination or prevent decontamination. In the following methods and results regarding preinvestigations and enhancement are presented. Preinvestigations are seen as a very important tool to optimize a biological treatment of a contaminated soil. By this means, the possibilities and limitations (how far can the pollutants be degraded) for the specific polluted soil can be predicted. Balances show what actually happens to the pollutants. In order to practice preinvestigations specific test systems must be available. Using these methods the remediation can be realized more cost effectively. Optimizing and enhancing the degradation processes is another measure for cost reduction.

In the course of the remediation of a PAH-contaminated site in Hamburg-Veringstrase (1) we evaluated the use of two different remediation strategies: 1. Stimulation of PAH degradation by activation of the autochthonous microflora. 2. Stimulation of the PAH degradation by supplementation of the soil with either the white rot fungus Pleurotus ostreatus (1), straw or compost (2).

Im Beitrag wird auf die Gefahren von mikrobiellem Befall von Dieselkraftstoffen hingewiesen. Die hier zugrunde liegende Studie befasste sich in der Hauptsache mit der Vermeidung einer solchen Kontamination. Daher werden in diesem Bericht stichpunktartig Massnahmen aufgefuehrt, die der Prophylaxe beim Bezug des Treibstoffes, der Prophylaxe bei der Lagerung des Treibstoffes und der Prophylaxe speziell fuer landwirtschaftliche Maschinen dienlich sind.