Das Projekt "Biologische Sanierung organisch kontaminierter Boeden in einem Biorottezellenreaktor" wird vom Umweltbundesamt gefördert und von Landkreis Gießen durchgeführt. Objective: The project is to clean up phenol-contaminated soil from an industrial waste dump. Cleaning is performed in a sealed composting container in which oxygen injection, air leaking, and recirculation of percolate water can be controlled. The contaminated soil is mixed with compost; phenol digestion taking place in natural organic material whenever lignin is decomposed, one expects that the microbial population of compost will be fairly well adapted to removing the contamination. Air emissions from the reactor can be controlled by either a carbon or a compost filter. General Information: Hydrocarbon-contaminated soil may be incinerated in order to clean it up. At low hydrocarbon concentrations, however, this method is too expensive to be taken into account. 'Soft' treatment technology, such as biological treatment, is an inexpensive solution which, however, takes long time when applied in situ. Therefore, on-site treatment within a bioreactor is an alternative to in-situ treatment. The Commission of the European Communities has granted assistance, within its ACE 89 programme on clean technology demonstration plants, to the LANDKREIS GIESSEN, Germany, for the treatment of phenol-contaminated soil in a biological rot-cell reactor. The project which was limited to the period of August, 1990, through October, 1992, performed successfully; all of the contaminated soil scheduled for treatment was satisfactorily cleaned up. The technology uses aerated rot cells the potential emissions of which are absorbed by a biofilter. The contaminated soil is mixed with compost which provides the necessary microbes capable of digesting phenol, as well as organic material and nutrients the microbes might need. Reactor retention time is less than two weeks. After this time, the soil contaminants are reduced to negligible concentrations; bad odours are totally removed. The soil may be used for landfilling. The economical assessment showed that the cost of the system was approximately 170 ECU/ton of soil treated. The project has shown that rather fast microbial treatment of phenol-contaminated soil is possible; as a side-effect, it was found that phenol out gassing from the compost-soil mixture and reduction of phenols during storage of the mixture on a heap were already significant, although requiring more time for odour removal than by the use of the bioreactor. Without the use of a bioreactor, treatment costs are approximately halved. Achievements: Phenol contaminated soil was treated in a biological rot cell reactor. The reactor performed successfully; all of the contaminated soil scheduled for treatment was satisfactorily cleaned up. The technology uses aerated rot cells, the potential emissions of which are absorbed by a biofilter. The contaminated soil is mixed with compost which provides the necessary microbes capable of digesting phenol, as well as organic material and nutrients the microbes might need...
Das Projekt "Biotrocknung" wird vom Umweltbundesamt gefördert und von Universität Bochum, Fakultät XII für Bauingenieurwesen, Lehrstuhl für Siedlungswasserwirtschaft und Umwelttechnik durchgeführt. Zur Behandlung von Abwasser-Klaerschlamm ist die Verfahrenskette Voreindickung, Stabilisierung, Nacheindickung sowie nunmehr auch Trockung und vollstaendige thermische Stabilisierung erforderlich. Durch die Ausnutzung der im organischen Material des (vorstabilisierten) Klaerschlammes gebundenen Energie soll der Anteil an Fremdenergie reduziert werden. Dazu kommen nur aerobe Behandlungsverfahren - fuer die Kompostierung - infrage, da bei diesen biochemischen Stoffumsetzungen eine erhebliche Energiemenge freigesetzt wird. Diese soll gezielt dazu genutzt werden, a) durch Selbsterhitzung des Materials eine entseuchende Wirkung zu erzielen und b) eine moeglichst weitgehende Trocknung des Ausgangsmaterials zu erreichen. Die Kompostierung des Klaerschlamms erfolgt in beluefteten, waermeisolierten Containern im grosstechnischen Massstab.