DD297069A5 - METHOD AND DEVICE FOR CLEANING CONTAMINANT BOEDES - Google Patents

Abstract

The invention relates to a method of cleaning soils contaminated by pollutants. In this method, the soil structure, without transporting the soil to the surface, is progressively loosened in each case inside at least one largely cylindrical soil body by means of a liquid introduced under high pressure. Apart from loosening the soil, the liquid also serves as a carrier and transport medium for at least one effective substance working and/or transforming the respective pollutant in situ. In this way, the effective substances, even in inhomogeneous soil structures, are uniformly distributed inside the respectively treated soil body (B) and are taken to the pollutants. <IMAGE>

Description

For this 2 pages drawings ^ -

Method and device for cleaning polluted soils

The invention relates to a process for the purification of soil containing pollutants (anthropogenic and geogenic formation) in which, without transport of the soil to the soil surface, a loosening of the soil structure by means of a liquid introduced under high pressure proceeds progressively within at least one substantially cylindrical bottom body. The invention further relates to a device for carrying out a floor cleaning method with a drill bit provided with a drill bit (drill pipe) with a feed channel and at least one just above the drill bit arranged outlet nozzle for the high pressure liquid emerging.

Methods are already known for the purification of pollutant-containing soils in which the pollutants are separated from the soil particles in a kind of laundry by means of a jet of water or cleaning medium injected under high pressure into the soil. The entsteher.de mixture of cleaning medium, pollutants and some soil particles is then fully or partially promoted to the soil surface, where then takes place in a treatment station reprocessing of the used water or cleaning medium. The separated pollutants werdin then possibly stored on a suitable landfill. Since it is unavoidable in this known method that in addition to the laden with pollutants cleaning medium and soil particles are transported to the soil surface, these withdrawn from the soil components, eg. B. silt, sand, be returned to the ground after complete cleaning in the work station or replaced by additives.

Furthermore, in situ soil cleaning methods are known which make use of the possibility of microbiological degradation of certain pollutant groups, by means of a targeted infiltration of nutrients into the soil from the soil surface or from specially prepared infiltration wells, the microorganisms naturally present in the soil be stimulated to increased metabolic activity. In one embodiment of this known method, the microorganisms intended for the treatment are also infiltrated into the soil in addition to the nutrients.

In terms of its structure, naturally grown soil is said to be inhomogeneous and anisotropic. Transitions between different soil layers are mostly abrupt and discontinuous. The different permeabilities, anisotropic properties as well as affinities and adsorption tendencies of the soil layers against an impurity or its aqueous solution or suspension often cause considerable hindrance in the implementation of microbiological in situ processes or even their failure. Not infrequently, even those soil layers are particularly intensively polluted, which have the lowest permeability. Therefore, if soil zones of different permeability are present, substances and microorganisms infused in aqueous solution tend to move and stay in soil layers of high flow permeability, in which the highest pollutant load is not necessarily dominant.

Nearly impermeable soil layers can limit the success of in situ microbiological processes or even the Prevent contact between pollutants and microorganisms altogether. The invention is based on the invention of a process for the purification of soil containing pollutants, in which the Elimination or transformation of pollutants not after transport to the soil surface, but in place

in the ground (in situ), without the need to create a foreclosure against the surrounding Bodc.i.

In addition, a suitable device for carrying out the method is to be created. For the technical solution of this problem is proposed with respect to the method that at least one with the liquid

the respective pollutant in place degrading and / or converting active ingredient is introduced into the loosened soil structure.

By loosening up the soil structure results in a homogenization and increasing the permeability of the soil,

whereby a condition for a targeted and effective delivery of the active ingredient is created. The active ingredient itself is using the liquid as a carrier and transport medium in the uniformed by the loosening

Introduced soil structure, whereby a homogeneous distribution of the active ingredient is achieved in the soil. By "active ingredient is meant a substance which is a biological, chemical or physical elimination or transformation

of the pollutant or a combination thereof. In particular, it may be the active ingredients, for example

Clearing agents act. These include microorganisms, nutrients and nutrients to stimulate the growth of existing ones

and / or supplied microorganisms as well as chemicals that promote the chemical degradation or modification of

Effect pollutant compounds. In addition, an addition of solvents or substances to increase the Flow permeability of the soil possible. For pollutant mobilization can also gases including air in

bring in the soil. The physically active substances include solidifying agents for pollutant fixation on the respective soil particles. Finally, it is possible to inject into the soil to neutralize the contaminated soil grains active ingredients that form a coat encapsulating the respective soil grain.

The inventive method supports the introduction of such agents by the soil to be treated by means of

of the injected under high pressure in the Bodon liquid jet is homogenized. As a result, an isotropic and continuous distribution of the active ingredient is ensured, so that chemical, physical or biological processes are set in motion, which lead to a degradation of the pollutants or their conversion into harmless reaction products.

From the known in situ method for soil washing, the inventive method differs in that Soil components and pollutants must not be promoted to the soil surface, so that there are no residues

anfallon.

The advantage over known in situ methods by infiltration of nutrients and / or microorganisms bosteht in the Bypassing of the slow and often ineffective flow process and its replacement with a highly effective Transport mechanism for all the necessary agents, which at the same time by this transport mechanism Soil structure is loosened and homogenized. In one embodiment of the method, the loosening of the soil structure and the simultaneous introduction at least

an active substance to the pollutants located in the loosened soil several times in succession

performed. In this way it is possible, for example, to introduce microorganisms and these supplying nutrients one after the other into the already loosened soil. Another possibility of the application is to first inject solvent into the already loosened soil, and then to add the active substance acting on the already dissolved pollutants.

In a further development of the method is provided that the removal of the loosening of the arch structure and the Transport of the active ingredient serving liquid from the soil at least one water conservation measure to produce

a flow gradient is set up and operated. This drainage measure may for example consist of a recessed in the ground well pipe, which maintains a continuous, funnel-shaped flow gradient within the soil. Serving as a carrier and transport medium fluid, z. B. water, accumulates as a result of the underground

Flow field in the well and is transported from there to the soil surface. It may be advantageous to introduce the withdrawn liquid back into the injection circuit, if necessary after renewed Addition of active ingredient. Since the pollutants remain in place in the soil, a cleaning of the means of As a rule, it is not necessary to drain the liquid withdrawn from the drainage measure, as these are the only ones that have not yet been discharged Contains active substance components. With regard to the device, a further feed channel is proposed for the technical solution of the task, which with

at least one outlet opening for the respective pollutant degrading and / or converting active ingredient in

Connection stands. According to a first embodiment of the device, the outlet opening opens above or below the outlet nozzle in the Sediment. In this way, it is possible to deliver the substance delivered via the outlet opening near the outlet opening

vorzulagern and then on the emerging from the outlet nozzle under high pressure fluid under simultaneous

Distribute soil loosening. In an alternative embodiment, the outlet opening into the outlet nozzle, so that the active ingredient of the high Pressure from the outlet nozzle escaping liquid entrained similar to a water jet pump and evenly in the ground

is distributed.

Further details and advantages of the subject matter of the invention will become apparent from the following description of the

accompanying drawings in which a preferred embodiment of the method according to the invention and two to

Implementing the method suitable devices are shown. In the drawings show Fig. 1: in a plan view of a schematic representation of a progressive method for cleaning pollutant-containing

Soils with a drill pipe driven vertically into the ground as well as a drainage measure in the form of a well pipe;

FIG. 2 shows a vertical cross section through the soil formation according to FIG. 1 through the plane of the drill pipe and the well pipe; FIG.

3 shows a partially sectioned illustration of the drill pipe in a first embodiment, and FIG. 4 shows a partially sectioned illustration of the drill pipe in a further embodiment.

In the illustrated in Figure 2, vertical section through an -odenformation is loaded with pollutants Floor area (S) below the floor surface (O) shown in dashed lines. In the ground is a well pipe 1 embedded,

the water level 2 is maintained by pumping below the liquid level in the ground, so that a shown in Fig. 2 dash-dotted lines, subterranean flow gradient 3 in the form of the well pipe 1 surrounding funnel.

A drill pipe 4 is by means of a drill bit 5 attached to its tip with simultaneous rotation 6 in the ground

driven. Once a just above the drill bit 5 arranged, provided with outlet nozzles 7 section dos

Drill pipe 4 passes into the loaded with pollutants soil area (S), one by means of a high pressure pump through the Drill pipe 4 transported liquid injected under high pressure via the outlet nozzles 7 in the ground. The

preferably radially emerging from the drill pipe 4 liquid jet 8 sweeps as a result of the rotational movement of the 6

Bohrrohres 4 and its simultaneous lowering a cylindrical bottom body (B), in which by the cutting and

swirling effect of the liquid jet 8 loosening and homogenization of the soil structure occurs. In this case, the diameter of the roughly cylindrical bottom body (B) is determined by the range of the action of the liquid stalk 8.

The liquid is an active ingredient attached, the high-pressure liquid itself serves as a carrier medium and

transported the active ingredient within the soil body (B) and distributed homogeneously.

The drug or agent will then access and act on this catfish to contaminants adhering to the soil particles

by degrading the pollutants chemically, physically or biologically and / or converted. The only one to

Loosening and fluid serving as a carrier and transport medium is subject to the effect of the Well pipe 1 artificially maintaining flow gradient 3 and is continuously fed through the well pipe 1 to the Ground surface (O) returned. The recycled liquid still has those proportions of agents that are not yet

the pollutants have entered into operative connection. The liquid returned to the soil surface (0) is enriched or supplemented in a corresponding device with further active ingredient and in turn introduced via the drill pipe into the contaminated soil body (B).

In Fig. 1 it is shown that the method described above is carried out progressively by the drill pipe 4th

successively driven at different locations 9 in the ground, so that by the plurality of treated thereby

Bodenkörper (B ') a nationwide floor cleaning process arises. Of course it is possible to To accelerate the cleaning process at the same time to work with several drill pipes. In hard to reach Floor areas, for example, below buildings, the active ingredient can also be driven over an obliquely into the ground Distribute drill pipe. After the floor area to be cleaned is treated in the manner described, the method can with

the same or a different active substance in whole or in part.

As a water conservation measure comes next to the use of the well pipe 1 and the use of others Drainage measures, for example, a trench pulled around the polluted soil area are possible. The drill pipe 4 shown in detail in Figure 3 has an outer shell 10 and a concentric thereto Inner casing 11. The inner casing 11 encloses a cylindrical feed channel 12, while between inner casing 11 and Outer jacket 10 is an annular further feed channel 13. Just above the drill bit 5, the drill pipe 4 has a narrowed with respect to its cross-section 14, in the

radially open the outlet nozzles 7. In the embodiment according to Figure 3, the outlet nozzles 7 are each formed on a radially disposed sleeve 15, the bore opens into the central feed channel 12.

Below the outlet nozzles 7 are also radially to the drill pipe 4 aligned outlet openings 16 which are connected to the

annular further supply channel 13 are in communication.

If the drill pipe 4 shown in FIG. 3 is used to carry out the method described, the active ingredient becomes

or the agent over the annular further feed channel 13 to can outlet openings 16 out and from there into the

Bodenkörper initiated. Due to the continuous rotating propulsion of the drill pipe 4 i'ir gets into the ground in this way

then injected drug in the range of the exiting at high pressure from the outlet nozzle 7

Liquid jet 8, whereby the active substance parts already in the soil upstream of the exiting under high pressure Liquid are detected and distributed with simultaneous loosening of the soil evenly within the soil body. In the case of the drill pipe 4 according to FIG. 4, the active substance flowing in via the annular further feed channel 13 passes over

formed as mixing nozzles outlet openings 17 even before the mouth of the outlet nozzles 7 in the under high pressure funded liquid, so that similar to the principle of a water jet pump strong turbulence and mixing of the

Agent occurs within the serving as a carrier medium liquid.

Claims (7)

1. A method for the purification of soil containing pollutants (anthropogenic and geogenic formation), in which without transport of the soil to the soil surface loosening of the soil structure by means of a high pressure liquid progressively takes place in each case within at least one substantially cylindrical soil body, characterized in that the liquid is introduced into the loosened soil structure at least one of the pollutant in place degrading and / or converting active ingredient. 2. The method according to claim 1, characterized in that the loosening of the soil structure and the simultaneous introduction of at least one active substance to the pollutants located in the loosened soil is carried out several times in succession. 3. The method according to claim 1 or 2, characterized in that for the removal of the loosening of the soil structure and the transport of the active ingredient serving liquid from the soil at least one water conservation measure is set up and operated to produce a flow gradient. 4. The method according to claim 3, characterized in that the withdrawn liquid is introduced again into the injection circuit. 5. Apparatus for carrying out the method according to at least one of claims 1 to 4, comprising a drill bit (4) provided with a drill bit (4) with a feed channel (12) and at least one outlet nozzle (7) arranged just above the drill bit (5). for the exiting at high pressure liquid, gekennzelc inet by a further feed channel (13), which is in communication with at least one outlet opening (16,17) for the respective pollutant degrading and / or converting active ingredient. 6. Apparatus according to claim 5, characterized in that the outlet opening (16) above or below the outlet nozzle (7) in the bottom body (B) opens. 7. Apparatus according to claim 5, characterized in that the outlet opening (17) opens into the outlet nozzle (7).