JP3815464B2 - Soil and groundwater purification composition - Google Patents

Description

  The present invention relates to a soil / groundwater purification composition as a carbon source used for soil and groundwater purification.

Conventional soil and groundwater treatment methods using in-situ microorganisms, such as those disclosed in Patent Document 1 and Patent Document 2, microbial carbon source (also referred to as carbon source, electron donor) in liquid soil, It was added to the ground water.
Japanese Patent Laid-Open No. 9-276894 Japanese Patent Application Laid-Open No. 11-90484

  In these conventional technologies, there is a problem that liquid carbon moves in the flow of groundwater, deviates from the target pollution source, and does not achieve the original purpose.

  The present invention effectively solves these conventional problems, and provides a soil for purifying purposes, a soil for supplying carbon for a long period of time by stopping the carbon source in a gel form at the groundwater position, and a groundwater purifying composition. is there.

  In order to solve these conventional problems, the present inventors have intensively researched and found that the following means can be used to effectively solve the problems of the present invention, and the present invention has been completed.

The present invention, soil consisting of fatty number particle size within a 1mm at 12 or more carbon atoms, alcohol, or, at least one or more organic material is selected or fatty acids and alcohols ester Le et al., Polyhydric alcohols, groundwater Consists of a purification composition.

ADVANTAGE OF THE INVENTION According to this invention, the soil and groundwater purification composition which supply carbon for a long period with respect to the soil and groundwater for purification purposes can be provided.

Hereinafter, the best mode for carrying out the present invention will be described in detail.
In this embodiment, any one of sorbitol, glycerin, and mannitol is used. These are polyhydric alcohols having a plurality of alcohol groups at the terminal, and gradually undergo biodegradation in an anaerobic atmosphere while generating hydrogen. It is thought that it will eventually become carbon dioxide and methane gas.

  The hydrogen generated at this time causes an exchange reaction between the chlorine atom of the organic chlorine compound to be purified and hydrogen, and is converted into harmless ethylene or ethane having no chlorine, thereby achieving purification.

In addition, organic substances selected from sorbitol, glycerin, and mannitol are liquid, so they are fluid and can easily move in soil and groundwater to reach the target pollution source, contributing to purification at that location. Is possible.

  Furthermore, by mixing in advance an organic substance selected from sorbitol, glycerin, and mannitol with another solid substance that contributes to purification, it is possible to transport the other solid substance that contributes to the pollution source.

  As the polyhydric alcohol used in the present embodiment, it is most preferable to use any one of organic substances selected from sorbitol, glycerin, and mannitol. However, those having low or no toxicity for environmental purification. If there is, it can be used similarly.

  The fatty acid, alcohol, ester of fatty acid and alcohol, and biodegradable resin used in this embodiment must have 12 or more carbon atoms. When the number of carbon atoms is less than 12, it is generally not preferable because it becomes liquid at room temperature, soil or groundwater environment, and it is difficult to stop at a pollution source. Further, the upper limit of the carbon number is not particularly specified, but about 22 which is commercially available and easily available as an industrial material is preferable.

  These fatty acids, alcohols, esters of fatty acids and alcohols, and biodegradable resins themselves are solid and have no fluidity, but are premixed with organic substances selected from sorbitol, glycerin, and mannitol, and holes provided from the ground such as wells. Can be easily reached by adding to the soil and groundwater, and then stays at the source for a long period of time, and continues to biodegrade as long as the organic matter selected from sorbitol, glycerin, and mannitol is used. It occurs over a period of time and contributes to purification.

  Examples of these fatty acids, alcohols, esters of fatty acids and alcohols, and biodegradable resins include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, lignoceric acid, behenic acid, and mixtures of these fatty acids. , Salts, hydrogenated products and the like.

  As the fatty acid mixture, simple fatty acids may be artificially mixed, or natural mixtures such as beef tallow fatty acid, coconut oil fatty acid, palm oil fatty acid, and rapeseed oil fatty acid may be used.

Further, beef tallow, pork tallow, cacao butter, coconut oil, palm oil, palm kernel oil, rapeseed and the like containing the fatty acid are also included.
Further, beef tallow, pork tallow, cacao butter, coconut oil, palm oil, palm kernel oil, rapeseed and the like containing the fatty acid are also included.

  Next, examples of the alcohol include lauryl alcohol, myristyl alcohol, stearyl alcohol, cetyl alcohol, behenyl alcohol, and mixtures and salts of these alcohols.

  As a mixture of alcohols, a simple alcohol may be artificially mixed or a natural mixture may be used.

Examples of fatty acid and alcohol esters include myristyl myristate, cetyl palmitate, stearyl stearate, methyl stearate, butyl stearate, cholesteryl stearate, batyl stearate, octyldodecyl behenate, behenyl behenate, and these Mixtures of esters and distearyl phthalates whose fatty acids are dibasic acids, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, sorbitan tristearate, sorbitan monobehenate, polyoxy Ethylene sorbitan monostearate, polyethylene glycol monostearate, polyethylene glycol distearate, sorbitan sesquistearate, sorbitan tristearate Hexostearic acid polyoxyethylene sorbite and mixtures of these esters, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene behenyl ether, glycerin cetyl ether, glycerin stearyl ether, polyoxyethylene Ethers such as polyoxypropylene cetyl ether, polyoxyethylene polyoxypropylene decyl tetradecyl ether, polyoxyethylene octyl phenyl ether, stearic acid monoglyceride, palmitic acid stearic acid monoglyceride, oleic acid monoglyceride, stearic acid monodiglyceride, stearic oleate Acid monodiglyceride, oleic acid stearate monoglyceride Ride, monoglyceride behenate, tetraglyceryl monostearate, tetraglyceryl tristearate, tetraglyceryl pentastearate, hexaglyceryl monostearate, hexaglycerate pentastearate, monostearic acid decaglycel, distearic acid decaglycel, tristearic acid decaglyceride, pentastearic acid decaglycerin, Examples include heptastearic acid decaglycel, decastearic acid decaglyceryl, monostearic acid polyoxyethylene glycerin, monostearic acid propylene glycol, and a mixture of these esters.

  Furthermore, examples of biodegradable resins include lactic acid polymers, copolymers of hydroxybutyric acid and hydroxyvaleric acid, condensation polymers of polyols and aliphatic dicarboxylic acids, poly (ε-caprolactone), and the like.

  Of the above organic substances, fatty acids which can be expected to be gelled by an ester reaction with an alcohol group are preferable, and stearic acid is particularly preferable because it is inexpensive and generates a large amount of hydrogen per unit weight.

  Linoleic acid and linolenic acid used in the present embodiment are unsaturated fatty acids having 18 carbon atoms, which are gradually biodegraded in soil and groundwater to release hydrogen, and are usually used in soil and groundwater. It is thought to exist as a liquid.

  The calcium compound used in the present embodiment is an inorganic calcium compound, which is used for preventing the early departure of organic substances in soil and groundwater by appropriate alkalinity and thickening action optimal for the growth of microorganisms. is there.

  From this viewpoint, it is preferable to select calcium carbonate having a particle size within 50 μm from the viewpoint of thickening action, alkalinity, and cost.

  Here, the greatest feature of the present embodiment is that when a specific organic substance having an alcohol group, a solid organic substance group having a particle diameter of 1 mm or less, and a calcium compound having a particle diameter of 50 μm or less coexist, The technical problem is to be solved effectively.

  In other words, solid fatty acids are gradually esterified by the ester reaction of carboxyl groups and alcohol groups, forming gel-like substances in soil and groundwater, and further increasing the production of calcium carbonate with a particle size of 50 microns or less. Due to the viscous action, it contributes to purification by stopping for a long time in the environment.

  In addition, solid organic substances other than fatty acids contribute to purification by limiting the fluidity in soil and groundwater due to the thickening action produced by calcium carbonate with a particle size of 50 microns or less, and stopping for a long time in the environment It is.

  Since sorbitol, glycerin, and mannitol are all polyhydric alcohols, there are many alcohol groups that contribute to the ester reaction, high thickening effect by inorganic substances such as calcium carbonate within 50 micron millimeters, safety The main reason is that it is highly biodegradable.

  These sorbitol, glycerin, and mannitol are not preferable unless 30% or more of the entire composition is present, because the fluidity of the entire composition and gel formation at a contamination source are insufficient. The upper limit is not particularly required, but is preferably about 90% in order to obtain effective hydrogen generation and thickening produced by other substance groups added to the composition.

  Nutrient salts of microorganisms other than organic substances (nitrogen, phosphorus, etc.) may be added and injected separately from the organic substance group used in the present invention, but by mixing and adding in advance to the composition of the present invention, Even if the nutrient salt is water-soluble, fluidization is restricted at the same position as the organic matter, and elution can be controlled, which is preferable.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.
Example 1
A total of 45 kg was weighed in a proportion of 100 parts by weight of glycerin, 10 parts by weight of stearic acid having an average particle diameter of 105 microns and 20 parts by weight of average particle size of 12 microns and calcium carbonate, and stirred with a blade having a rotation speed of 150 rpm (diameter 30 cm). A uniform soil, groundwater purification composition was obtained.

  The composition showed a gel state in which the components were uniformly dispersed, no sedimentation or separation phenomenon of the components was observed, and the fluidity was good.

  45 kg of this composition was added directly to the 22m underground aquifer (saturated aquifer) using a pump through a 16 cm diameter enbi pipe inserted into a well dug (20 cm in diameter). Easy.

  Next, as a result of analyzing the water quality of the aquifer at the point where the composition was added after 110 days, it was found to be 14.1 mg / L in the initial stage. Trichlorethylene was reduced to 0.4 mg / L.

  This is because the microorganisms decomposed trichlorethylene by biodegrading the added composition and generating hydrogen.

  In addition, no increase in organic matter (measured by TOC) was observed from the observation well provided on the downstream side of the groundwater flow of 1.5 m from the point of addition, and the composition of this example was soil, groundwater No phenomenon deviating from the source of contamination due to maintaining the gel state in the environment or the progress of gelation was not observed.

(Example 2)
100 parts by weight of sorbitol, 5 parts by weight of lauric acid having an average particle size of 85 microns, 8 parts by weight of myristyl alcohol having an average particle size of 40 microns, 5 parts by weight of calcium carbonate having an average particle size of 25 microns, and an average particle size of 15 microns A total of 50 kg was weighed at a ratio of 0.1 part by weight of potassium dihydrogen donor for phosphorus, and stirred with wings (diameter 30 cm) at a rotation speed of 150 rpm to obtain a uniform soil and groundwater purification composition.

This composition shows a gel state in which the components are uniformly dispersed, and there is no sedimentation or separation phenomenon of the components.
The fluidity was good.

  45 kg of this composition was added directly to an aquifer (saturated aquifer) 5 m underground through a 16 cm diameter enbi pipe inserted into a well dug (diameter 20 cm). Easy.

  Next, as a result of analyzing the water quality of the aquifer at the point where the composition was added after 180 days, it was found to be 3.0 mg / L in the initial stage. Trichlorethylene was reduced to 0.02 mg / L.

  This is because the microorganisms decomposed trichlorethylene by biodegrading the added composition and generating hydrogen.

In addition, no increase in organic matter (measured by TOC) was observed from the observation well provided on the downstream side with respect to the flow of groundwater of 1.5 m from the added point, and the composition of this example was soil, groundwater No phenomenon deviating from the source of contamination due to maintaining the gel state in the environment or the progress of gelation was not observed.
Example 3
50 kg in total at a ratio of 100 parts by weight of mannitol, 5 parts by weight of a lactic acid polymer having an average particle diameter of 200 μm, 5 parts by weight of stearyl stearate having an average particle diameter of 20 μm, and 5 parts by weight of calcium carbonate having an average particle diameter of 25 μm Weighed and stirred with wings (diameter 30 cm) with a rotation speed of 150 rpm to obtain a uniform soil and groundwater purification composition.

  The composition showed a gel state in which the components were uniformly dispersed, no sedimentation or separation phenomenon of the components was observed, and the fluidity was good.

  45 kg of this composition was added directly to a 8.5-m underground aquifer (saturated aquifer) through a 16 cm diameter enbi pipe inserted into a well dug (diameter 20 cm), but continuously added. Was very easy.

  Next, it was left to stand in a state where the well opening was provided with a lid, and the water quality of the aquifer at the point where the composition was added after 144 days was analyzed. As a result, 6.3 mg / L was initially present. Trichlorethylene was reduced to 0.09 mg / L.

  This is because the microorganisms decomposed trichlorethylene by biodegrading the added composition and generating hydrogen.

  In addition, no increase in organic matter (measured by TOC) was observed from the observation well provided on the downstream side of the groundwater flow of 1.5 m from the point of addition, and the composition of this example was soil, groundwater No phenomenon deviating from the source of contamination due to maintaining the gel state in the environment or the progress of gelation was not observed.

In addition, the addition amount and combination of various materials shown in this Example are examples, and the main points of the present invention are not impaired depending on various conditions such as target soil, groundwater environment, cost, etc. Needless to say, the range can be changed.
Example 4
A total of 55 kg was weighed in a ratio of 100 parts by weight of glycerin, 5 parts by weight of linoleic acid, 2 parts by weight of linolenic acid, and 10 parts by weight of an average particle size of 10 microns, and stirred with feathers (diameter 30 cm) at a rotation speed of 150 rpm. A uniform soil and groundwater purification composition was obtained.

  The composition showed a gel state in which the components were uniformly dispersed, no sedimentation or separation phenomenon of the components was observed, and the fluidity was good.

  50 kg of this composition was added directly to a 4.5-m underground aquifer (saturated aquifer) using a pump through a 16 cm diameter enbi pipe inserted into a well dug (diameter 20 cm). Was very easy.

  Next, as a result of analyzing the water quality of the aquifer at the point where the composition was added after 110 days after standing naturally with a cover provided on the ground opening of the well, 0.72 mg / L was initially present. Trichlorethylene was reduced to 0.02 mg / L.

  This is because the microorganisms decomposed trichlorethylene by biodegrading the added composition and generating hydrogen.

  In addition, no increase in organic matter (measured by TOC) was observed from the observation well provided on the downstream side of the groundwater flow of 1.5 m from the point of addition, and the composition of this example was soil, groundwater No phenomenon deviating from the source of contamination due to maintaining the gel state in the environment or the progress of gelation was not observed.

  In the examples of the present invention, the addition to the soil and groundwater is exemplified by the direct addition from the well, but the addition method is not limited to this, for example, excavating contaminated soil on the ground, A method of mechanically stirring and backfilling with the composition of the present invention, a method of adding to a groove formed by a civil engineering machine instead of a well, and a method of adding simultaneously while digging a well can be arbitrarily selected. Not too long. According to this embodiment, organic chlorine compounds such as trichlorethylene can be purified in situ by microbial reaction under anaerobic conditions.

The purification composition according to the present invention can be used for purification of soil or groundwater containing an organic chlorine compound.

Claims (5)

Sorbitol, glycerin, and at least one or more organic material selected from mannitol, at least one or more organic material the number of carbon atoms particle size of 12 or more fatty acids within 1 mm, alcohols are selected or fatty acids and alcohols ester Le et al And a soil or groundwater purification composition comprising a calcium compound having a particle size of 50 microns or less. Soil composed of at least one organic substance selected from sorbitol, glycerin, and mannitol, at least one organic substance selected from oleic acid and linolenic acid, and a calcium compound having a particle size of 50 microns or less, or Groundwater purification composition. The soil or groundwater purification composition according to claim 1, wherein the fatty acid is stearic acid. The soil or groundwater purification composition according to claim 1, wherein the calcium compound is calcium carbonate. The soil or groundwater purification composition according to claim 1, wherein the content of at least one organic substance selected from sorbitol, glycerin, and mannitol is 30% by weight or more.