TWI450745B - Additives for cleaning mineral oil-contaminated medium and cleaning method - Google Patents

Description

Additive and purification method for purifying medium contaminated by mineral oil

The present invention relates to a harmless agent for mineral oil and a method for detoxifying mineral oil which are added to a medium such as soil, ground water or ground soil in a contaminated area.

As a method of purifying an environment contaminated with harmful chemicals, a method of purifying by microorganisms has attracted attention. Compared with the conventional physical and chemical treatment methods, this method has lower energy and equipment costs, and can be easily purified in situ as a major advantage. Such bioremediation can be divided into: bio-augmentation by adding foreign microorganisms having high decomposition ability of pollutants, and fertility by supplying nutrients to microorganisms. Bio-stimulation for purifying the metabolic power of pollutants.

The bio-enhancement method using foreign microorganisms is progressing toward practical use while considering the microbial mutations and spreading to the outside of the region. On the other hand, the biostimulation method can utilize indigenous microorganisms, and it is only necessary to add nutrients and other materials to the target environment, and is increasingly used in the in-situ purification project of most polluted places.

In order to solve the problem of the conventional biological rejuvenation agent for the organochlorine compound, the present inventors have disclosed the use of the organic chlorine compound by the anaerobic microorganism in the purification of the organic chlorine compound, and disclosed in Patent Document 1 and Patent Document 2 Additives used in the repair of contaminated soil, groundwater or sessile soils. These additives have high water solubility as a nutrient source and energy source, and have good biodegradability, so they are easily diffused in the soil and cause no dissolved oxygen (DO: Dissolved Oxygen (hereinafter referred to as "DO"). The step of bonding the oxygen (the O of NO _x ) to the anaerobic state allows the step of decomposing and purifying the organochlorine compound to proceed rapidly.

As a result, the interval between the wells for injecting the nutrient can be increased, and the effect can be spread over a wide range by injecting from a small number of places. Further, the organic chlorine compound can be decomposed and purified before the influence of the substance is disturbed, so that the amount of work in the purification can be reduced, and the shortening of the purification period can be achieved. Furthermore, since the component having high biodegradability in the environment is selected, the material becomes carbon dioxide and water after the purification is completed, and does not remain on site.

[Previous Technical Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-185870

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2005-288276

As described above, in the biological re-cultivation of a conventional organochlorine compound, for example, in the case where bioremediation is applied to in situ purification, a technique using anaerobic microorganisms is mainstream. On the other hand, it is effective to use a biological rejuvenation method using aerobic microorganisms as a mineral oil represented by benzene, gasoline, or the like.

The object of the present invention is to provide a harmless agent for mineral oil and a harmless method for mineral oil, which is characterized in that soil, ground water or bottom soil is contaminated by mineral oil, and the mineral oil is purified in situ and effectively. In the method, a detoxifying agent which purifies contaminants by a local microorganism for a short period of time is applied, whereby the burden on the environment is reduced and the environment before use can be quickly restored.

The harmless agent for mineral oil of the present invention is characterized by comprising more than one peptone, yeast extract, arginine, histidine, isoleucine, lysine, threonine, guanamine Acid, more than one of manganese, zinc, iron, magnesium, cobalt, nickel, copper, molybdenum, sodium, potassium, calcium, and the like, more than one thiamine, p-aminobenzoic acid, choline, ascorbic acid Pantothenic acid, pyridoxine, riboflavin, nicotinic acid, biotin, inositol, folic acid, lipoic acid, cyanocobalamin, more than one ammonium salt, and more than one phosphoric acid Made up of salt.

Further, the method for detoxifying a mineral oil according to the present invention is characterized by the steps of: subjecting a target medium to an aerobic state; and supplying more than one type of sputum, yeast extract, arginine, group Amine acid, isoleucine, lysine, threonine, valine, more than one of manganese, zinc, iron, magnesium, cobalt, nickel, copper, molybdenum, sodium, potassium, calcium and the like , more than one thiamine, p-aminobenzoic acid, choline, ascorbic acid, pantothenic acid, pyridoxine, riboflavin, nicotinic acid, biotin, inositol, folic acid, lipoic acid, cyanocobalamin, A step of treating a mineral oil of the present invention with one or more ammonium salts and one or more phosphates.

The mineral oil detoxifying agent of the present invention further comprises one or more kinds of fatty acid sodium, monoalkyl sulfate, alkyl polyoxyethylene sulfate, alkylbenzenesulfonate, monoalkyl phosphate, alkyl di Methylamine oxide, alkylcarboxybetaine, polyoxyethylene alkyl ether, fatty acid sorbitan ester, alkyl glycan, fatty acid diethanolamine, alkyl monoglyceride, potassium fatty acid, α-sulfo group Sodium fatty acid ester, sodium linear alkylbenzene sulfonate, sodium alkyl sulfate, sodium alkyl ether sulfate, sodium α-olefin sulfonate, sodium alkyl sulfonate, sucrose fatty acid ester, sorbitan fat Acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid alkanolamine, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, alkyl amino fatty acid sodium, alkyl betaine, alkyl Amine oxides, alkyltrimethylammonium salts, dialkyldimethylammonium salts, rhamnolipids, mannosyl erythritol esters.

Pressure can be applied if the water permeability of the target medium is less than 10 ^-4 cm/sec. Further, the step of setting the target medium to an aerobic state is preferably a step of subjecting the target medium to a pH range of 5.5 to 9.0 and injecting water having a DO concentration of 5 mg/L or more.

The step of making the target medium into an aerobic state may be such that the target medium has a DO concentration of 2 mg/L or more and an Oxidation-reduction Potential (ORP) (hereinafter referred to as "ORP") of 0 mV or more. The steps of the aerobic state.

【effect】

The harmless agent of the mineral oil of the present invention and the method for detoxifying the mineral oil using the same are used to supply the substance as a target medium, and the microorganism is activated and proliferated as a nutrient source or a respiratory source, thereby making the mineral oil harmless. Chemical.

In this way, considering the functional role of all the microorganisms constituting the microbial group involved in the process of decomposing the mineral oil, a plurality of substances having different properties are supplied as an additive, whereby bioremediation which is efficient and does not easily residue harmful substances can be achieved. method.

Further, by matching the soil quality of the repaired object, the blending ratio of each substance constituting the additive can be set to improve the repairing effect.

According to the detoxifying agent of mineral oil and the detoxifying method of mineral oil of the present invention, the mineral oil can be purified quickly and at low cost.

Hereinafter, the best form of the mineral oil detoxifying agent of the present invention and the method for detoxifying the mineral oil of the present invention will be described.

The "one or more ammonium salts" used in the mineral oil detoxifying agent of the present invention are, for example, one or more kinds of ammonium sulfate, diammonium hydrogen phosphate, etc., and all substances which are structurally identified or evaluated as ammonium salts can be used as This ammonium salt is used. The water solubility is preferably higher, and when the target medium is supplied, it is more effective to improve the effect of the present invention by being more mobile from the supply place.

Further, the "one or more phosphates" used in the mineral oil detoxifying agent of the present invention are, for example, one or more kinds of diammonium hydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, etc., and all of them may be structurally A substance identified or rated as phosphate is used as the phosphate. The water solubility is preferably higher, and when the target medium is supplied, it is more effective to improve the effect of the present invention by being more mobile from the supply place.

The target medium in the detoxifying agent of the mineral oil of the present invention and the detoxification method of the mineral oil, for example, the soil, the groundwater or the bottom soil in which the indigenous microorganisms are present, as long as the medium is an environment in which the microorganisms can survive, even by The same effect can be obtained by adding microorganisms from the outside.

The harmless agent for mineral oil of the present invention is added to a medium such as soil, ground water or sumpy soil in a polluted area. The compounding ratio of each substance constituting the harmless agent of the mineral oil of the present invention can be improved by the nature of the medium to improve the repairing effect.

Further, the form of the additive is a solid form, a liquid form, a slurry form, or the like, and is determined depending on the geological state of the stratum in the contaminated area or the pollution state of the contaminated area. The supply method is usually a method in which it is dissolved in water and then supplied to a medium, but the same effect can be obtained by a method of mixing with a machine or a medium.

The object to be harmlessly used in the present invention is a mineral oil, for example, a substance such as benzene, toluene, xylene, ethylbenzene or the like, gasoline, kerosene or light oil, but generally only those substances which are identified as mineral oil or mineral oil Yes, it is not limited to this.

The microorganism used in the detoxification of the mineral oil detoxifying agent of the present invention is present in contaminated soil, and the microorganism which can be proliferated by the same method as the general microorganism can contain inorganic salts, nitrogen sources, and other nutrient sources. A microorganism which is proliferated in an inorganic nutrient medium, an organic nutrient medium or the like to detoxify mineral oil. Alternatively, it may be applied to the detoxifying agent and the detoxifying method of the contaminant of the present invention by mixing a foreign microorganism, or using a recombinant microorganism extracted from the microbial gene, or immobilizing the microorganism on the monomer.

More than one type of sputum, yeast extract, arginine, histidine, isoleucine, lysine, threonine, valine, more than one of manganese, zinc, iron, magnesium, cobalt, nickel, Copper, molybdenum, sodium, potassium, calcium and these salts, more than one thiamine, p-aminobenzoic acid, choline, ascorbic acid, pantothenic acid, pyridoxine, riboflavin, nicotinic acid, biotin , inositol, folic acid, lipoic acid, cyanocobalamin, one or more ammonium salts, and an additive composed of one or more phosphates, as a nutrient source for the activation and proliferation of microorganisms that decompose pollutants The type and amount of the substance to be used can be selected depending on the type and concentration of the target pollutant, the type of the medium, and the type of microorganism to be used.

From more than one of sodium fatty acid, monoalkyl sulfate, alkyl polyoxyethylene sulfate, alkyl benzene sulfonate, monoalkyl phosphate, alkyl dimethyl amine oxide, alkyl carboxy betaine, poly Oxyethylene vinyl ether, fatty acid sorbitan ester, alkyl glycan, fatty acid diethanolamine, alkyl monoglyceride, potassium fatty acid, sodium α-sulfo fatty acid ester, sodium linear alkylbenzene sulfonate , sodium alkyl sulfate, sodium alkyl ether sulfate, sodium α-olefin sulfonate, sodium alkyl sulfonate, sucrose fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester , fatty acid alkanolamine, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, alkyl amino fatty acid sodium, alkyl betaines, alkyl amine oxides, alkyl trimethyl ammonium salts, two An additive composed of an alkyldimethylammonium salt, a rhamnolipid, and a mannose erythritol ester is a substance group for facilitating the migration of mineral oil adsorbed in the soil to the aqueous phase. The material that moves the soluble substance to the water, and is used to improve the harm of the microorganism to make the target substance harmless. Of (Bioavailability) effective lines, is visible in the food industry as a harmful substance having low use of food additives and the like.

The oxygen supply or the kneading with the soil is not limited. The method of dissolving in water and supplying it to the medium in the form of DO is preferable in terms of the diffusion in the medium and the influence of the surface. As an optimum method, a DO concentration of 2 mg/L or more is formed by injecting water having a DO concentration of 5 mg/L or more, from the viewpoint of activation and proliferation of an aerobic microorganism for decomposing a target pollutant. An aerobic state having an ORP value of 0 mV or more is desirable.

In the case where water in which the detoxifying agent or oxygen of the present invention is dissolved is supplied to the medium, the injection method is preferably selected in accordance with the water permeability coefficient indicating the index through which water easily passes. That is, when the water permeability coefficient is less than 10 ^-4 cm/sec, it is appropriately supplied by natural flow by applying pressure and a water permeability coefficient of 10 ^-4 cm/sec or more.

In the present invention, since the mineral oil is quickly detoxified by the use of microorganisms, it is used in an environment which is generally suitable for the survival of microorganisms, or it is necessary to form an environment and manage it. In this regard, it is preferred to have a pH in the range of 5.5 to 9.0.

Under the above conditions, the present invention makes the mineral oil harmless. Therefore, even in the case of a contaminated medium which is difficult or time consuming to use the conventional purification method, the present invention is a purification method which can be harmless while reducing the environmental burden, shortening the construction period, and reducing the cost.

Hereinafter, the detoxifying agent for mineral oil and the method for detoxifying mineral oil of the present invention will be described in more detail by way of Examples, but the technical scope of the present invention is not limited to the examples.

[Example 1]

An example of detoxifying benzene in groundwater by the detoxifying agent of mineral oil of the present invention and the detoxification method of mineral oil is exemplified.

In order to actually verify the purification effect of the additive in the in-situ purification of benzene-contaminated groundwater, a small test was carried out where the groundwater was confirmed to be contaminated with benzene. The plane area of the small test site is 10m long × 10m wide, and the groundwater level is 2.2m. The thickness of the object layer from the surface is 5m. In this test, the concentration of benzene (benzene, toluene, xylene), the DO concentration (mg/L), and the ORP value (mV) were measured as parameters.

The concentration of benzene was determined by a gas chromatography mass spectrometer based on a public analysis method (JIS-K0125). The additives used in this test were a mixture of 2 kg of yeast extract, 2 kg of arginine, 1 kg of ascorbic acid, 350 kg of diammonium phosphate, 50 kg of potassium chloride, 5 kg of sodium chloride, 50 kg of dipotassium hydrogen phosphate, and 20 kg of sucrose fatty acid ester.

50 tons of tap water at the site, the additive was mixed into the groundwater while being mixed in the tank, and the oxygen was dissolved in the tap water at an average of 20 mg/L. The flow rate in minutes is continuously injected into the groundwater. The soil permeability coefficient of the site was 5.1×10 ^-3 cm/sec, so it was injected into the well by natural flow.

As a comparative example, a method of injecting air into the well water is performed on the same site.

In both cases, an observation well was placed at a position 0.5 m and 3 m downstream of the groundwater flow from the injection well, and the DO concentration (mg/L) in the groundwater was periodically measured.

Further, in the present embodiment, the concentration of benzene and the ORP value (mV) in the groundwater were periodically measured.

The measurement results of the respective parameters in the above Example 1 and Comparative Example are shown in Table 1.

As can be seen from Table 1, by the injection of the additive, the DO and ORP in the contaminated area become suitable conditions for aerobic decomposition by microorganisms, and a decomposition environment for pollution is formed, which is maintained during the test period. The concentration of the target benzene was reduced to the extent of meeting the environmental standard after 15 to 30 days from the start of the test. On the other hand, in the case of the aeration method of the prior art shown in the comparative example, the oxygen concentration is temporarily observed at an initial stage of 0.5 m from the injection well, but thereafter it is reduced to 2 mg/L or less and cannot be supplied. Adequate oxygen required for aerobic microbial activity. The reason for this is that the aeration of the injection well causes the bubbles to accumulate around the well, which hinders the subsequent movement of water and oxygen. From the above results, it was confirmed that the detoxifying agent of the mineral oil of the present invention and the detoxifying method of the mineral oil are effective in purifying the mineral oil (especially benzene) in the groundwater by microorganisms.

[Example 2]

An example of detoxifying benzene in groundwater by the detoxifying agent of mineral oil of the present invention and the detoxification method of mineral oil is exemplified.

In order to actually verify the purification effect of the additive in the in-situ purification of groundwater contaminated with mineral oil, a small test was carried out where the groundwater was confirmed to be contaminated by mineral oil. The plane area of the small test site is 10m long × 10m wide, and the groundwater level is 1.5m. The thickness of the object layer from the surface is 3m.

In this test, the mineral oil was measured using a concentration of total petroleum hydrocarbon (hereinafter referred to as TPH), a DO concentration (mg/L), and an ORP value (mV) as parameters. The concentration of TPH was measured using a gas chromatograph (hereinafter referred to as GC-FID) equipped with a hydrogen flame ionization detector. The additives used in this test were 2 kg of peptone, 2 kg of sulphate, 1 kg of riboflavin, 220 kg of diammonium hydrogen phosphate, 30 kg of potassium chloride, 5 kg of sodium chloride, 5 kg of magnesium chloride, 30 kg of dipotassium hydrogen phosphate, and sorbose. A mixture of alcoholic anhydride fatty esters of 20 kg.

30 tons of tap water at the site, the additive was mixed into the groundwater while being mixed in the tank, and the oxygen was dissolved in the tap water at an average of 30 mg/L. The flow rate in minutes is continuously injected into the groundwater. The soil permeability coefficient of the site is 1.4×10 ^-3 cm/sec, so it is injected into the well by natural flow. An observation well was placed at a position 2 m downstream of the groundwater flow from the injection well, and the TPH concentration, the DO concentration (mg/L), the ORP value (mV), and the pH were periodically measured. The measurement results of the respective parameters in Example 2 are shown in Table 2.

As can be seen from Table 2, by the injection of the additive, the DO and the ORP in the contaminated area become suitable conditions for aerobic decomposition by microorganisms, and a decomposition environment for the pollution is formed, which is maintained during the test period. The target mineral oil is reduced to below the lower limit of quantitation 30 days after the start of the test. From the above results, the detoxifying agent for mineral oil and the method for detoxifying mineral oil of the present invention have proven to be effective for purifying mineral oil in groundwater by microorganisms.

Claims (5)

A harmless agent for detoxifying mineral oil in a contaminated medium, which is composed of more than one type of peptone, yeast extract, arginine, histidine, isoleucine, lysine, threonine, Lysine; more than one of manganese, zinc, iron, magnesium, cobalt, nickel, copper, molybdenum, sodium, potassium, calcium, and the like; more than one thiamine, p-aminobenzoic acid, choline , ascorbic acid, pantothenic acid, pyridoxine, riboflavin, nicotinic acid, biotin, inositol, folic acid, lipoic acid, cyanocobalamin; more than one ammonium salt; more than one phosphate; and more than one Sodium fatty acid, monoalkyl sulfate, alkyl polyoxyethylene sulfate, alkyl benzene sulfonate, monoalkyl phosphate, alkyl dimethyl amine oxide, alkyl carboxy betaine, polyoxyethylene alkyl Ether, fatty acid sorbitan ester, alkyl glycan, fatty acid diethanolamine, alkyl monoglyceride, potassium fatty acid, sodium α-sulfo fatty acid ester, sodium linear alkylbenzene sulfonate, alkyl sulfate Sodium ester, sodium alkyl ether sulfate, sodium α-olefin sulfonate, sodium alkyl sulfonate, sucrose fatty acid ester, mountain Sugar anhydride fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid alkanolamine, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, alkyl amino fatty acid sodium, alkyl beet It is composed of a base, an alkylamine oxide, an alkyltrimethylammonium salt, a dialkyldimethylammonium salt, a rhamnolipid, and a mannose erythritol ester. A method for detoxifying mineral oil in a contaminated medium consisting of the steps of: subjecting the target medium to an aerobic state; and supplying more than one such extract, yeast extract, arginine, histidine , isoleucine, lysine, threonine, valine; more than one of manganese, zinc, iron, magnesium, cobalt, nickel, copper, molybdenum, sodium, potassium, calcium, and the like; The above thiamine, p-aminobenzoic acid, choline, ascorbic acid, pantothenic acid, pyridoxine, riboflavin, nicotinic acid, biotin, inositol, folic acid, lipoic acid, cyanocobalamin; one or more Ammonium salt; more than one phosphate; and more than one sodium salt, monoalkyl sulfate, alkyl polyoxyethylene sulfate, alkyl benzene sulfonate, monoalkyl phosphate, alkyl dimethyl amine Oxide, alkylcarboxybetaine, polyoxyethylene alkyl ether, fatty acid sorbitan ester, alkyl glycan, fatty acid diethanolamine, alkyl monoglyceride, potassium fatty acid, α-sulfofatty acid ester Sodium, sodium linear alkylbenzene sulfonate, sodium alkyl sulfate, alkyl ether sulfate Sodium, sodium α-olefin sulfonate, sodium alkyl sulfonate, sucrose fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid alkanolamine, polyoxyethylene alkyl Ether, polyoxyethylene alkylphenyl ether, sodium alkylamino fatty acid, alkyl betaines, alkylamines The step of detoxifying a mineral oil composed of an oxide, an alkyltrimethylammonium salt, a dialkyldimethylammonium salt, a rhamnolipid, and a mannose erythritol ester. A method for detoxifying mineral oil in a contaminated medium as described in claim 2, wherein pressure is applied when the water permeability coefficient of the target medium is less than 10 ^-4 cm/sec. The method for detoxifying mineral oil in a contaminated medium according to the second aspect of the invention, wherein the step of making the target medium into an aerobic state is such that the pH range of the target medium is between 5.5 and 9.0, and the injection is performed. A step of dissolving oxygen at a concentration of 5 mg/L or more. A method for detoxifying a mineral oil in a contaminated medium according to the second aspect of the invention, wherein the aerobic state is such that the target medium has a dissolved oxygen concentration of 2 mg/L or more and an oxidation-reduction potential value of 0 mV or more. .