JP2005144345A - Method of purifying polluted soil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of removing the pollutants from soil polluted with harmful pollutants which is characterized by causing a purifying solution against the pollutants to penetrate the soil deeply and efficiently and permitting purification of polluted soil in a short period. <P>SOLUTION: The method comprises drilling a hole in soil 5 with a drilling shaft 2 of a working machine 1 while pouring water and, after the drilling, rotating the shaft 2 while pouring a purifying solution 10, during pulling up of the shaft 2. The pouring of water and the solution is carried out by spraying into soil 5 under high pressure with a high-pressure pump 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for removing harmful pollutants in situ from soil contaminated with harmful pollutants and efficiently purifying the soil in a short period of time.

  In recent years, in the vicinity and ruins of chemical factories and dust incineration facilities, PCBs and dioxins and other harmful pollutants that have leaked and scattered from chemical factories and dust incineration facilities have penetrated deep into the ground, causing serious contamination of soil and groundwater. There is a need to remove harmful pollutants and clean up the soil.

Under such circumstances, as a conventional method for removing harmful pollutants in soil, for example, as disclosed in JP-A-2003-1236, a removal agent for removing harmful pollutants is sprayed on a contaminated soil layer. Or after spraying the removal treatment agent on the contaminated soil layer, water was spread or the removal treatment agent was dug up and contaminated with the soil.

  These methods are simple and inexpensive, and are effective removal treatment methods in a wide range of contaminated areas. However, the removal treatment agent is difficult to penetrate deeply into the ground and has a problem that it takes time to penetrate. .

  Further, as disclosed in Japanese Patent Application Laid-Open No. 2003-80221, in the contaminated soil position, the underground structure is left as it is, and iron powder as a soil purifier is directly supplied to the contaminated soil in the lower layer, and stirred and mixed. There is a construction method that purifies the contaminated soil by dispersing it in the ground near the contaminated soil.

However, this method involves excavation, agitation, and mixing while discharging iron powder from the end of each shaft such as a multi-axis auger, which has a problem in soil permeability.
JP2003-1236 JP 2003-80221 A

  In view of the above, the present invention, when removing harmful pollutants from soil contaminated with harmful pollutants, permeates the pollution processing solution of the harmful pollutants deeply and efficiently into the soil and purifies the contaminated soil in a short period of time. It is intended to provide a method for remediating contaminated soil that makes it possible.

  In order to solve the above-mentioned problem, the method for purifying contaminated soil according to the first aspect of the present invention is to drill a hole in the soil while pouring water at the excavation shaft of the construction machine when drilling, and after the drilling, when the excavation shaft is lifted The excavating shaft is rotated while the liquid is injected, and the excavating shaft is pulled up.

By adopting such a method, it is possible to inject the purification treatment solution deep into the soil in a short time, and to remove harmful pollutants by exerting functions such as decomposition and alteration to harmful pollutants.

  The injection of the purification treatment liquid is when the drilling shaft is pulled up after drilling with the excavation shaft. Is promoted, penetrates in a short time, expands the range of penetration, and penetrates evenly.

  Next, the purification method for contaminated soil of the present invention according to claim 2 is characterized in that, in the purification method according to claim 1, water injection and injection are injected into the soil at high pressure.

  By adopting such a method, the sprayed water and the purification treatment liquid are strongly sprayed on the soil, so that the lump of the soil is made fine, and the water and the purification treatment liquid penetrate into the soil in a wide range, and evenly. To penetrate.

  Next, the purification method for contaminated soil of the present invention according to claim 3 is the purification method according to claim 1 or 2, wherein the lifting speed of the excavation shaft is automatically measured while measuring the depth of the drilling hole and the flow rate of the purification treatment liquid. It is characterized by being performed.

  By setting it as such a method, a purification process liquid is supplied to soil in a uniform quantity.

  Next, the purification method of the present invention contaminated soil according to claim 4 is the purification method according to claim 1, 2, or 3, wherein the purification treatment liquid is a highly permeable water obtained by subdividing water molecule clusters, A high carbonaceous and highly porous fine powdery activated carbon mixed in the highly permeable water is a main constituent.

By using such a purification treatment liquid, the high permeability water combines the high permeability action and the internal structural action of the activated carbon to induce and disperse the fine powder of activated carbon widely in the soil. Deeply penetrate.
On the other hand, activated carbon fine powder dispersed widely and deeply in the soil takes in a large amount of harmful pollutants contained in the soil due to its internal structure and physical action, and decomposes or modifies the incorporated harmful pollutants to be harmless. Make it a proper substance.

According to the method for purifying contaminated soil according to the present invention, water is injected at the time of drilling the soil with the excavation shaft, and the purification treatment liquid is injected at the time of pulling up, so work is not wasted.
And at the time of injection of the purification treatment liquid, the permeability is increased because it is pre-injected into the soil, and in particular, in combination with the high penetration action of the purification treatment liquid, it penetrates uniformly in a wide range in a short time, The soil contaminated with harmful pollutants can be purified in a short period of time.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a front view of an apparatus used for carrying out the method for purifying contaminated soil of the present invention, and FIGS. 2 to 5 are process diagrams of the method for purifying contaminated soil of the present invention.
In the figure, 1 is a conventionally known construction machine such as a ground improvement excavator, 2 is a drilling shaft of the construction machine 1, the drilling shaft 2 is formed in a hollow tube body, and a high-pressure hose 3 is inserted therein.
In addition, the excavation shaft 2 penetrates vertically into the soil, and excavation blades 4 are fixed to the tip, and the excavation shaft 2 is driven to rotate and drill holes in the soil 5.

Water 8 is fed into the high pressure hose 3 by a high pressure pump 7 from a water tank 6 installed on the ground. Further, instead of the water 8, the purification treatment liquid 10 is fed into the high pressure hose 3 from the purification treatment liquid tank 9 via the high pressure pump 7 by a switching device (not shown) such as a valve.
Water 8 or purification treatment liquid 10 pumped to the high-pressure hose 3 by the high-pressure pump 7 is sprayed into the soil in a horizontal direction at a high pressure from a spout provided on the lower side surface of the excavation shaft 2 by the tip nozzle 11 of the high-pressure hose 3. Is done.
In the figure, 12 is an agitation plant and 13 is a generator.

The purification treatment liquid 10 is mainly composed of highly permeable water obtained by subdividing water molecule clusters, and high carbonaceous and highly porous finely powdered activated carbon mixed in the highly permeable water.
The ratio of the high permeability water and the fine powder of the high carbonaceous and highly porous activated carbon constituting the purification treatment liquid 10 is appropriately set according to the contamination degree and the penetration state of the contaminated soil. The mixing ratio of osmotic water and activated carbon is in the range of 5:10 to 100: 30.

Highly osmotic water is obtained by subdividing water molecule clusters, and is actually stabilized by fusing subdivided water molecule clusters into carbinols such as ethyl alcohol and isopropyl alcohol. is there.
This highly permeable water has a high osmotic effect due to the subdivided water molecule clusters, and also has a substance-inducing effect that induces various liquids and fine powder solids to the soil layer. .

  As an example of preparing this highly permeable water, an aqueous solution prepared by mixing 35 wt% to 55 wt% of carbinol having 2 to 4 carbon atoms with pure water, purified water, or general water treated with a strong magnetic field is treated. The water molecule clusters in the liquid to be treated are subdivided by stirring the liquid in a sprayed state at a temperature of 10 ° C. or lower, and then the water molecule clusters in the subdivided state are carbinol at a temperature in the range of 80 ° C. to 83 ° C. Fuse with molecules. As a result, highly permeable water is prepared in which the subdivided water molecule clusters are stably maintained for a long period of time.

On the other hand, the activated carbon in the form of high carbon and highly porous fine powder (activated carbon fine powder) has a carbonization rate of 90% or more, a specific surface area of 1000 m ² / g or more, and a pH of 9.0 to 11.0. Compared with general activated carbon, it has a high carbonization rate, a high specific surface area, a unique PH region, and an internal structure in which innumerable fine pores are continuous.

Therefore, according to this purification treatment liquid 10, the high permeability water combines the high permeability action and the internal structural action of the activated carbon to induce and disperse the activated carbon fine powder widely in the soil. Deeply penetrate.
On the other hand, activated charcoal fine powder widely and deeply dispersed in the soil takes in a large amount of harmful pollutants contained in the soil and decomposes or denatures the incorporated harmful pollutants by its internal structural and physical action. Use harmless substances.

  In addition, harmful pollutants in the soil in which the purification treatment liquid 10 effectively acts include polychlorinated biphenyls, dioxins, and other organic chlorine compounds such as dichloromethane, dichloroethane, carbon tetrachloride, trichloroethane, tetrachlorethylene, Examples include chloropropane, organic phosphorus compounds, cyanide compounds, cadmium, lead, arsenic, mercury, and the like.

Next, a method for purifying contaminated soil using the above apparatus will be described with reference to the drawings.
The construction machine 1 is placed on the ground surface of the contaminated soil, and the excavation shaft 2 is driven to rotate and penetrates into the soil 5. In parallel with this penetration, water 8 is pumped into the high-pressure hose 3 by the high-pressure pump 7 and the water is injected into the soil 5 from the spout of the rotating excavation shaft 2 so that the excavation shaft 2 penetrates and drills. (FIG. 2). When the tip of the excavation shaft 2 reaches the bottom of the contaminated area, the drilling is stopped (FIG. 3).
The depth of the drilling hole is preset according to the situation of the contaminated area and is not constant. By the injection of the water 8 at the time of drilling, the soil becomes soft and loosened.

When the drilling is completed, the purification treatment liquid 10 is pumped into the high-pressure hose 3 by the high-pressure pump 7 in place of the water 8, and this time, the purification treatment liquid is injected into the soil 5 after water injection from the jet port of the excavating shaft 2 that rotates in reverse. While 10 is injected, the excavation shaft 2 is pulled up in parallel with this (FIGS. 4 and 5).
The purification treatment liquid 10 penetrates into a region having a radius of 1000 mm around the excavation shaft 2 (below the environmental standard value), thereby extracting, decomposing and purifying harmful pollutants contained in the gas in the soil and groundwater.

  The excavation shaft 2 is lifted by adjusting the pulling speed while measuring the depth of the drilling hole and the flow rate of the purification treatment liquid 10 with a measuring instrument (not shown) provided in the construction machine 1. Thereby, the purification treatment liquid 10 is supplied in a uniform amount.

  In this way, the entire area of the area that needs to be cleaned is sequentially cleaned in a column shape, but the construction may be a lap type construction so that parts of the areas overlap each other, or parts of the areas may be mutually connected. It is good also as a contact circle type construction to touch.

It is a front view of the apparatus used in order to implement this invention method. It is process drawing which shows the operation | work order of this invention method. It is process drawing which shows the operation | work order of this invention method. It is process drawing which shows the operation | work order of this invention method. It is process drawing which shows the operation | work order of this invention method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Construction machine 2 Excavation shaft 3 High pressure hose 4 Excavation blade 5 Soil 6 Water tank 7 High pressure pump 8 Water 9 Purification processing liquid tank 10 Purification processing liquid 11 Nozzle 12 Stirring plant 13 Generator

Claims (4)

  Drilling water while pouring water at the excavation shaft of the construction machine into the soil during drilling, and after excavation, rotating the excavation shaft while injecting purification treatment liquid when pulling up the excavation shaft, and lifting the excavation shaft Purification method for contaminated soil.   2. The method for purifying contaminated soil according to claim 1, wherein the water injection and injection are carried out at a high pressure in the soil.   The method for purifying contaminated soil according to claim 1 or 2, wherein the lifting speed of the excavation shaft is automatically performed while measuring the depth of the drilling hole and the flow rate of the purification treatment liquid.   The clarification treatment liquid is mainly composed of highly permeable water obtained by subdividing water molecule clusters and high carbonaceous and highly porous activated carbon mixed in this highly permeable water. The method for purifying contaminated soil according to claim 1, 2 or 3.

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