Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
  • B09C—RECLAMATION OF CONTAMINATED SOIL
  • B09C1/00—Reclamation of contaminated soil
  • B09C1/10—Reclamation of contaminated soil microbiologically, biologically or by using enzymes
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
  • C12N1/00—Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
  • C12N1/20—Bacteria; Culture media therefor
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
  • C12N1/00—Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
  • C12N1/20—Bacteria; Culture media therefor
  • C12N1/205—Bacterial isolates
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12R—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES C12C - C12Q, RELATING TO MICROORGANISMS
  • C12R2001/00—Microorganisms ; Processes using microorganisms
  • C12R2001/01—Bacteria or Actinomycetales ; using bacteria or Actinomycetales

Definitions

• the invention relates to a method for the microbiological decontamination of materials contaminated with pollutants, in particular permeable soils, which among other things. may be contaminated with polychlorodibenzodioxins, polychlorodibenzofurans, polychlorinated biphenyls, halogenated diphenyl ethers, chlorinated phenols and benzenes and with hexachlorocyclohexane.
• the method can be used for the remediation of soils, for example from old locations in the chemical industry.
• the pollutants leading to toxic soil contamination can encompass a wide range of substances.
• mineral oil hydrocarbons aromatic or polycyclic aromatic hydrocarbons, volatile chlorinated hydrocarbons, phenol compounds, chlorophenols and non-volatile chlorine compounds as well as polychlorinated biphenyls, dioxins and furans should be mentioned here.
• impurities are mixed contaminants, i.e. the soil is loaded with a variety of chemical substances to varying degrees.
• Pollutants can accumulate in soils e.g. spread through elution and remobilization, and some of them are also enriched in the soil, so that these contaminants pose a high risk potential.
• contaminated sites refers to old sites and old deposits, provided that they pose or are expected to pose a threat to the environment, particularly human health.
• thermal processes, chemical-physical processes, soil air extraction processes and biological processes are used for cleaning floors.
• the pollutants contained in the soil are oxidized by direct or indirect action of thermal energy or transferred into the gas phase and destroyed in the thermal aftertreatment.
• the thermal processes are particularly suitable for the disposal of highly concentrated organic pollutants in soils, they lead to less than 1% residual products that have to be disposed of in a special way.
• the chemical-physical processes for soil remediation include processes for extracting pollutants by means of floor washing, they differ from one another primarily by the selected classification and separation processes and by different washing media. However, this results in 10 to 30% highly contaminated residues that are difficult to dispose of.
• REPLACEMENT LEAF Bodenlufl suction methods are only suitable for the remediation of soils that are contaminated with volatile organic substances, e.g. B. with chlorinated hydrocarbons, which have been widely used as solvents in the past.
• the contaminated soil air is extracted in-situ by vacuum and cleaned on site using an activated carbon filter.
• Microbiological processes are expected to have a wide range of applications in the decontamination of soils. They aim to accelerate the breakdown of organic compounds by activating and optimizing existing bacteria and by adding specially bred microorganisms.
• the desired end products of aerobic degradation of organic substances are carbon dioxide and water.
• Physico-chemical properties of the pollutants such as water solubility, lipophilicity or volatility, as well as the structure of the molecules that determine the biological vulnerability and the extent of their degradation, are just as important as soil-specific conditions such as grain composition, homogeneity, pore volume and permeability.
• the biological treatment of the soil is usually carried out in such a way that contaminated soils are prepared and rented on a sealed surface.
• the boxed floor is covered with organic matter, e.g. ground pine bark (Shell BIOREG process) or straw mixed in order to offer the microorganisms favorable development conditions (Chem.-Ing. -Tech. 59 (1987), No. 6, p. 461).
• organic matter e.g. ground pine bark (Shell BIOREG process) or straw mixed in order to offer the microorganisms favorable development conditions (Chem.-Ing. -Tech. 59 (1987), No. 6, p. 461).
• the object of the invention is to develop a method for microbiological decontamination of materials contaminated with pollutants, in particular permeable soils, which makes it possible to redevelop large-scale company premises which are mainly contaminated with pesticides or intermediate products of crop protection and pesticide products.
• microorganism suspension for decontamination which preferably contains at least 3 representatives of the following microorganisms in equal proportions:
• microbiological decontamination of permeable soils takes place in such a way that the autochthonous microorganisms present in the soil, adapted to the pollutants, are activated in a manner known per se by setting suitable milieu conditions and the named microorganism suspension is sprayed over the loosened soil to be rehabilitated or infiltrated into the soil , whereby in the case of the in-situ method, at least 80 g of biomass per square meter of soil are used in the appropriate nutrient medium and in the case of the on-site or off-sweet method, at least 250 g of biomass are used per square meter of soil in the appropriate nutrient.
• a modified culture solution according to Meyer and / or a modified glucose nutrient broth are mainly used as culture media for growing the microorganism suspension.
• chlorinated phenoxy compounds are added to the nutrient medium for growing the microorganism suspension using a conventional carbon source and, if appropriate, with the addition of the main contaminants of the soil as an additional carbon source and inducer.
• the smooth microbial degradation of the dioxins, in particular the "Seveso" poison 2,3,7,8-tetrachlorodibenzo-p-dioxin, by the microbial mixed population according to the invention is extremely surprising. It is well known that these substances are problematic in terms of their biodegradability. They are practically insoluble in water, are very strongly adsorbed in the soil and are difficult to attack due to their structure.
• Another advantage of the process according to the invention is the fact that it is also possible to microbiologically break down the ⁇ -hexachlorocyclohexane. As is known, this substance has hitherto been considered difficult or not at all degradable (J.E.M. Beurskens et al., Ecotoxicology and Environmental Safety 21, 128-136 (1991)).
• the process also allows highly contaminated material, such as heaped-up heaps, to be mixed with building rubble, for example, and then to be decontaminated in rents.
• the mixed microorganism population is grown using the submerged method at 25 ° C in the following nutrient solutions:
• REPLACEMENT LEAF c 20 ml of a methanolic soil extract from 100 g of contaminated soil or
• Another possibility of modification consists in growing the microorganisms in a standard nutrient solution with the following composition (glucose nutrient broth):
• the 240 mg / 1 2,4-dichlorophenoxyacetic acid are added. If necessary, the peptone portion can be replaced by an appropriate amount of NH4CI or urea.
• the mixed culture is cultivated as such or, after the individual microbes have been grown separately, the mixed population is produced in appropriate media.
• microorganism suspension used according to the invention preferably contains, in equal proportions, at least 3 representatives of the following microorganisms
• the soil samples were taken on the site of a company whose most important production lines include the production of pesticides.
• the floors are primarily contaminated with polychlorodibenzodioxins, polychlorodibenzofurans, halogenated diphenyl ethers, chlorinated phenols and benzenes, and hexachlorocyclohexane.
• Dibenzodioxins (total) Dibenzo relationane (total) TCDD (toxicity equivalent according to BGA)
• Tetrachlorobenzenes (total) Hexachlorobenzene Hexachlorocyclohexane ⁇ -HCH ß-HCH ⁇ -HcH ⁇ -HCH 2,4-dichlorophenol
• REPLACEMENT LEAF The basic nutrient solution used for cultivation was used to activate the autochthonous microflora.
• Soil which was mainly contaminated with the pollutants named under 3, was treated with the mixed population according to the invention in the greenhouse.
• 350 ml of soil were mixed with 40 ml of the microorganism suspension, which contained 3 g of solid substance / 100 ml.
• test vessels were set up in the dark at changing temperatures (10 to 25 ° C). The surface of the floor was moistened daily. After 4 weeks, the pollutants were analyzed again in comparison to an untreated control. The breakdown rates are summarized in Tables II to IV.
• Table II Reduction in the content of diphenyl ether, chlorophenols and chlorobenzenes through microbial degradation after a single treatment
• Table HE Reduction in the content of hexachlorocyclohexane due to microbial degradation after a single treatment
• Table IV Reduction of the levels of dioxins and furans by microbial degradation after a single treatment
• Soil temperature from + 5 ° C to + 49 ° C (1 cm soil depth)
• Air temperature from + 3 ° C to + 32 ° C (1.50 m height) average rainfall: 250 l / m 2 / year approx. 461 in the test period
• Soil temperature from + 5 ° C to + 49 ° C (1 cm soil depth)
• Air temperature from + 3 0 C to + 32 ° C (1.50 m height) average rainfall: 250 lm 2 / year

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Biotechnology (AREA)
• Organic Chemistry (AREA)
• Zoology (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Genetics & Genomics (AREA)
• Wood Science & Technology (AREA)
• General Health & Medical Sciences (AREA)
• Biomedical Technology (AREA)
• Microbiology (AREA)
• Tropical Medicine & Parasitology (AREA)
• Biochemistry (AREA)
• General Engineering & Computer Science (AREA)
• Virology (AREA)
• Medicinal Chemistry (AREA)
• Molecular Biology (AREA)
• Mycology (AREA)
• Soil Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• Processing Of Solid Wastes (AREA)
• Micro-Organisms Or Cultivation Processes Thereof (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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• 1992
  • 1992-04-21 DE DE4213019A patent/DE4213019C1/de not_active Expired - Fee Related
• 1993
  • 1993-03-16 SK SK237-94A patent/SK282987B6/sk unknown
  • 1993-03-16 EP EP93905192A patent/EP0596051A1/fr not_active Withdrawn
  • 1993-03-16 WO PCT/DE1993/000238 patent/WO1993020679A2/fr not_active Application Discontinuation
• 1994
  • 1994-02-21 FI FI940822A patent/FI940822A/fi not_active Application Discontinuation

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