JP6161408B2 - Contaminated soil mixing method - Google Patents

Description

  The present invention relates to a contaminated soil mixing method in which a nutrient for activating at least microorganisms in the contaminated soil is added to and mixed with the contaminated soil.

As a contaminated soil purification method that activates microorganisms in the contaminated soil and purifies the contaminated soil,
(1) Biosti that purifies the contaminated soil by activating the microorganisms in the contaminated soil by adding nutrients to activate the microorganism to the indigenous microorganisms originally inhabiting the contaminated soil Simulation.
(2) Bioaugmentation that purifies contaminated soil by activating microorganisms in contaminated soil by adding microorganisms, nutrients, and the like that have been recognized in advance to the contaminated soil.
It has been known.
Then, as a specific method of the contaminated soil purification method, a nutrient is added to the contaminated soil, and these are kneaded and mixed to form a biopile in which the contaminated soil is raised in an embankment form. In addition, there is known a biopile construction method that activates microorganisms in the biopile to promote the decomposition of the pollutants in the contaminated soil (see, for example, Patent Document 1).
There is also a land farming method that adds nutrients to contaminated soil and mixes them by agitation, switching, etc., and activates microorganisms in the contaminated soil to promote the decomposition of contaminants in the contaminated soil. ing.

JP 2006-255633 A

In order to activate microorganisms in the contaminated soil, the water permeability and air permeability of the contaminated soil are important. In particular, when the microorganism is an aerobic bacterium, the air permeability of the contaminated soil is extremely important.
However, in the case of contaminated soil that contains a lot of silty or viscous soil such as the Kanto Loam Formation and Okinawa's red soil, the soil is also poorly breathable and water permeable, and water and nutrients are added to the contaminated soil. When mixed, a fist-sized lump of contaminated soil is generated, making it difficult for nutrients and oxygen to enter the lump and activating microorganisms in the contaminated soil. There was a problem that the decomposition of was not promoted.
The present invention can prevent agglomeration of contaminated soil, improve air permeability and water permeability of the contaminated soil, and activate microorganisms in the contaminated soil when at least nutrients are added to and mixed with the contaminated soil. Provide a contaminated soil mixing method.

Contaminated soil mixing method according to the present invention, it Nodules prevention materials and the addition by Ru polluted soil mixing mixing for preventing Nodules of the nutrients for activating the contaminating soil microbial polluted soil polluted soil In this method, after the agglomeration preventing substance is introduced into the container, the contaminated soil and nutrients are introduced into the container and mixed while operating the agitation means in the container into which the agglomeration preventing substance is introduced . Therefore, the agglomeration of the contaminated soil can be prevented, the air permeability and water permeability of the contaminated soil can be improved, and the microorganisms in the contaminated soil can be activated.
Also, because rice husk is used as an agglomeration-preventing substance, the contaminated soil can be prevented from agglomeration, the air permeability and water permeability of the contaminated soil can be improved, and the microorganisms in the contaminated soil can be activated. The method can be realized at low cost .

The flowchart which shows the contaminated soil mixing method.

Embodiment 1
The contaminated soil mixing method according to the first embodiment is shown in FIG. 1 in which the nutrient for activating microorganisms in the contaminated soil and the agglomeration preventing substance for preventing the agglomeration of the contaminated soil are added to and mixed with the contaminated soil. Thus, the rice husk throwing step S1 and the kneading step S2 are provided.

In the rice husk charging step S1, rice husk (rice chaff) as an example of an agglomeration preventing substance is charged into a kneading work container as a container in which the kneading work is performed in the kneading apparatus.
A plurality of kneading rods as stirring means are provided in the kneading work container.
The kneading rod has, for example, a stirring blade on the circumferential surface of the rod, and both ends of the rod are rotatably supported on opposite side walls of the kneading work container so as to be able to rotate around the center line of the rod. It is a configuration. That is, when a plurality of kneading rods configured to rotate by rotation output of a motor or the like as a rotation drive source rotate in the kneading work container, the kneading object accommodated in the kneading work container Is agitated by a stirring blade and kneaded.
In the rice husk charging step S1, the rice husk in an amount of about 10% or less (for example, 1% to 2%) by weight based on the mixed contaminated soil created by the kneading operation is placed in the kneading work container.

In the kneading step S2, while rotating a kneading rod with a plurality of stirring blades in the kneading work container into which the rice husks are charged (that is, while kneading), microorganisms such as contaminated soil, moisture, and decomposing bacteria, Nutrients or the like for activating the microorganisms are kneaded and put into a working container and kneaded. The kneading time may be about several minutes (for example, about 2 to 3 minutes).
Examples of microorganisms include oils in contaminated soil contaminated with fuel oils (jet fuel, gasoline, light oil, heavy oil, etc.) and machine oils (lubricant oil, etc.), and solvents (eg, trichloroethylene, tetrachloroethylene, etc.) Decomposing bacteria (for example, petroleum degrading bacteria, VOC degrading bacteria, etc.) that decompose volatile organic compounds in the contaminated soil contaminated with) may be used. Moreover, nutrient salts, compost, etc. may be used as nutrients.

  In the first embodiment, before the kneading work, the rice husks are put into the kneading work container and then the kneading work is performed. Aggregation of contaminated soil is prevented by adsorbing particles to rice husk. In other words, before the contaminated soil is agglomerated in the process of kneading, the rice husk prevents the soil particles of the contaminated soil from being bonded to each other, thereby preventing agglomeration of the contaminated soil.

In Embodiment 1, as an auxiliary material when kneading contaminated soil, moisture, microorganisms, nutrients, etc., rice husks that prevent the agglomeration of the contaminated soil and retain the breathability and water permeability of the contaminated soil are used. Mixing that can reduce the particle size of contaminated soil to several millimeters, improve the air permeability and water permeability of the contaminated soil, activate microorganisms in the contaminated soil, and promote the decomposition of contaminants in the contaminated soil It will be possible to create contaminated soil.
In addition, since the rice husk in an amount of about 10% by weight or less based on the mixed contaminated soil created by the kneading operation is put into the kneading work container, the amount of rice husk can be reduced and the rice husk is not bulky. The kneading operation can be easily performed.
In addition, since cheap rice husks are used, mixed contaminated soil having good air permeability and water permeability can be produced at low cost.

Embodiment 2
The contaminated soil is dried before being kneaded and put into a working container and kneaded.
Then, mixed contaminated soil is prepared by adding dried kneaded soil, moisture, microorganisms, nutrients, and the like into a kneading work container in which rice husk is added and empty kneading operation is performed.
When the contaminated soil has a high water content, the contaminated soil is likely to agglomerate by kneading. Thus, after the contaminated soil is dried and kneaded as in the second embodiment, the contaminated soil agglomerates. Create mixed contaminated soil that can increase the prevention of contamination, improve the air permeability and water permeability of the contaminated soil, activate microorganisms in the contaminated soil, and promote the decomposition of contaminants in the contaminated soil Will be able to.

In addition, in this application, even if contaminated soil, a water | moisture content, microorganisms, a nutrient, etc. are knead | mixed and polluted soil is agglomerated, it does not have an effect. Therefore, the timing of adding rice husks as an agglomeration-preventing substance may be before the contaminated soil is agglomerated. For example, contaminated soil, moisture, microorganisms, nutrients, and the like and rice husk may be kneaded at the same time and placed in a working container to perform the kneading operation.
However, if contaminated soil and rice husks are added at the same time, lumps may be generated at that time, so add rice husks in advance as much as possible and pour contaminated soil, moisture, microorganisms, nutrients, etc. Better.

  A substance other than rice husk may be used as the agglomeration preventing substance. For example, plant materials such as straw, sawdust, and sugarcane pomace (bagasse) may be used.

In addition, the contaminated soil mixing method of this invention should just be the method of adding and mixing at least a nutrient and the agglomeration prevention substance for preventing agglomeration of contaminated soil to contaminated soil.
That is, in the contaminated soil purification method of the present invention, in order to improve the air permeability and water permeability of the contaminated soil, at least nutrients and agglomeration preventing substances are added to the contaminated soil, and these are kneaded, stirred, and switched. Any method can be used as long as they are mixed together. In other words, in biostimulation, indigenous microorganisms that originally inhabit contaminated soil are mixed with nutrients to activate the microorganisms, or in bioaugmentation. When adding and mixing microorganisms, nutrients, etc. that have been confirmed to be effective in advance to the soil, mixing with an agglomeration-preventing substance as in the present invention can prevent agglomeration of the contaminated soil and contaminate it. Since the air permeability and water permeability of the soil can be improved and microorganisms in the contaminated soil can be activated, the decomposition of the contaminants in the contaminated soil can be promoted.
As a means for mixing, a dedicated stirring machine, a machine such as a backhoe or a stabilizer, human power, etc. may be used.

S1 Rice husk charging step, S2 kneading step.

Claims (2)

A nutrient with Nodules prevention materials and the addition Ru mixed polluted soil mixing method for preventing the baby boom of polluted soil in order to activate the contaminating soil microbial contaminated soil,
After the agglomeration preventing substance is introduced into the container, the contaminated soil and nutrients are introduced into the container and mixed while operating the agitation means in the container into which the agglomeration prevention substance is introduced. Contaminated soil mixing method. The contaminated soil mixing method according to claim 1, wherein rice husk is used as the agglomeration preventing substance .

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