KR100559166B1 - Method of Biological Restoration of Soil Pollution with Oil with Peat Moss - Google Patents

Abstract

The present invention is a biological restoration method of oil-contaminated soil using pitmos,

Iii) measuring the oil concentration of the contaminated soil and the initial fertility index (nutritionality) of the soil;

Ii) adjusting the pH of the soil by adding quicklime (CaO) or calcium carbonate (CaCO ₃ ) so that the pH of the soil is 7;

Iii) mixing 20 to 60% by weight of the oil adsorbent made of pitmoss with the contaminated soil;

Iii) adding 18-22 kg of nutrient medium and 45-55 g of corrosion promoter to 1 m 3 of soil for activation of indigenous oil oxidizing microorganisms inhabiting contaminated soil;

Iii) re-adjusting the pH of the soil so that the pH of the soil is set to 7 by adding CaO to the soil in the same manner as in step ii);

Iii) inverting the soil twice a month to supply sufficient oxygen to the indigenous oil oxidizing microorganisms and injecting the nutrient medium and the corrosion promoter according to the method of step iv) from time to time so that the pH of the soil is maintained;

It relates to a biological restoration method of oil-contaminated soil using pitmoss, characterized in that it comprises a.

The present invention shows an excellent oil adsorption power from the soil contaminated with oil using the oil adsorbent manufactured using pitmoss, quickly adsorbs oil, etc., in particular, indigenous oil oxidizing microorganisms using nutrient medium and corrosion promoter It is a soil pollution restoration method that biologically decomposes the adsorbed oil by activating it, and it is excellent in decomposing effect of oil, so that the soil can be restored in a short time, thereby minimizing the loss of economic activity area. Since it plays a role as an excellent manure after the final restoration to the material, it is not only environmentally friendly but also does not incur secondary treatment costs, thereby reducing costs.

Oil adsorbent, soil pollution, restoration method, peat moss, peat, peat, microbial materials, nutrient medium, corrosion promoter

Description

Method of Biological Restoration of Soil Pollution with Oil with Peat Moss}

      The present invention relates to a method for biological restoration of oil-contaminated soil using pitmoss, and more particularly, by using an oil adsorbent composed of lipophilic peat moss together with nutrients such as nitrogen, phosphorus and potassium, and corrosion accelerators. The present invention relates to a biological restoration method of oil-contaminated soils using pitmoss, which inactivates indigenous oil-oxidizing microorganisms in contaminated soils, decomposes oils contaminated with soils, and restores contaminated soils.

In general, the contamination of oil in soil causes changes in the morphological, physical, chemical and microbiological properties of the soil, which not only threaten ecosystems, but also result in loss of fertile land and loss of economic activity. Done.

As a method of treating soil contaminated with oil, the contaminated soil is collected and sent to a landfill or cleaned in a special area, which is expensive and additional environmental is needed in another region. There is a possibility of loss.

Currently, the oil adsorbent mainly used is an inorganic adsorbent, a natural organic adsorbent, or a method of removing oil using a synthetic adsorbent.

As the inorganic adsorbent, vermiculite (biotite), perlite, perlite, silicate, clay particles and the like are used, which can absorb oil up to 4 to 8 times its own weight. Natural organic adsorbents include cotton, straw, bales, corncobs, moss, sawdust, etc., which absorb oil three to six times their own weight. Synthetic adsorbents use synthetic plastic fibers (polyethylene, polypropylene) or plastic foam (polyurethane) and can absorb oil up to 20 to 25 times its own weight.

However, such oil adsorbents must be recovered after adsorbing oil contaminated with soil or sea, and the recovered oil adsorbents must be incinerated, resulting in the generation of soot and harmful gases, as well as economic losses. It also causes other air pollution.

Therefore, recently, a method of removing oil contaminated with sea or soil using a porous material, pit moss, has been newly adopted as a solution for solving the above problems.

Peat moss is peat and plants such as moss, reeds, and sedges, and sometimes woody fluids such as pine and birch are thickly deposited in the basin and undergo biochemical changes such as fungus in the presence of water. Decomposed and altered, it is also called peat. Unlike the wood, which is buried underground like coal, is produced by long-term pressure and geothermal action (called coalification), the main component of plant material. Phosphorus ligline, cellulose, etc. are mainly produced by decomposition of the surface. Such pit moss is a porous material, which can absorb water close to 20 times its maximum weight, and is highly used as an oil adsorbent as well as a soil improving agent because of its excellent breathability.

Therefore, in recent years, an environmentally friendly method for removing oil pollution, which can be decomposed in nature by using an oil adsorbent using pitmos and microorganisms having the above characteristics, has been proposed.

In the Republic of Korea Patent Publication No. 2003-24230, which is filed with the above-mentioned proposal and published on March 26, 2003, the invention related to a biological biodegradable adsorbent comprising a matrix in which oil-decomposing microorganisms are fixed to overdried peat moss is known. The present invention is not only inconvenient to separately culture microorganisms having oil resolution, but also has to be inconvenient to work separately, such as soil cover for the cultivation of land even after the adsorption removal of oil.

The microorganisms separated from the laboratory are often inadequate to the actual natural environment, and especially when the microorganisms are injected into oil-contaminated soils, it is difficult to compete with indigenous microbial communities and lose the on-site adaptation. Easy to do In addition, most microbial agents tend to have low oil degradation efficiency in areas with high concentrations of oil, due to the lack of oxygen or the influencing substances required for microbial growth, unlike laboratory conditions.

In particular, when using a combination of microorganisms of different genera to complement the oil decomposition ability, the microbial degradation of the microorganisms of different genera may not be complementary to each other, so the ability of oil degradation of each microorganism may be rather deteriorated. Relying only on identified oil decomposing capabilities can lead to risks of secondary pollution and disrupting the ecological balance.

Therefore, to solve the above problems,

The present invention relates to a biological restoration method of oil-contaminated soil using peat moss, wherein the oil adsorbent for adsorbing the contaminated oil is composed of pit moss having a lipophilic property, and uses an indigenous oil oxidizing microorganism inhabiting the oil adsorbent in the soil. The purpose is to provide a biological restoration method of oil-contaminated soil using peat moss, characterized in that environmentally friendly decomposition.

Another object of the present invention is to administer the oil adsorbent composed of lipophilic phytmos to the soil and then to the soil by administering nitrogen, phosphorus, kali, etc., nutrients of microorganisms, to the active activity of indigenous oil oxidizing microorganisms inhabiting the soil. The present invention provides a method for biologically restoring an oil-contaminated soil using pit moss, characterized by improving the decomposition ability of the adsorbed oil.

Another object of the present invention is to supply a corrosion accelerator after administering an oil adsorbent composed of lipophilic peat moss, thereby promoting the rapid decomposition of the oil adsorbent adsorbing the contaminated oil, thereby quickly restoring the contaminated soil. The present invention provides a method for biological restoration of oil-contaminated soil using peat moss.

The present invention relates to a biological restoration method of oil-contaminated soil using peat moss, and more specifically, using an oil adsorbent made of lipophilic lip moss together with a nutrient medium composed of nitrogen, phosphorus, potassium, etc. The present invention relates to a biological restoration method of oil-contaminated soil using peat moss, which activates indigenous oil oxidizing microorganisms in contaminated soil to decompose oil contaminated with soil and promptly restores the contaminated soil.

Hereinafter, the present invention will be described in detail.

The present invention is a biological restoration method of oil-contaminated soil using pitmos,

Iii) measuring the oil concentration of the contaminated soil and the initial fertility index (nutritionality) of the soil;

Ii) adjusting the pH of the soil by adding quicklime (CaO) or calcium carbonate (CaCO ₃ ) so that the pH of the soil is 7;

Iii) mixing 20 to 60% by weight of the oil adsorbent made of pitmoss with the contaminated soil;

Iii) adding 18-22 kg of nutrient medium and 45-55 g of corrosion promoter to 1 m 3 of soil for activation of indigenous oil oxidizing microorganisms inhabiting contaminated soil;

Iii) re-adjusting the pH of the soil so that the pH of the soil is set to 7 by adding CaO to the soil in the same manner as in step ii);

Iii) inverting the soil from time to time to supply sufficient oxygen to the indigenous oil oxidizing microorganisms and injecting the nutrient medium and the corrosion promoter according to the method of step iv) from time to time so that the pH of the soil can be maintained;

It relates to a biological restoration method of oil-contaminated soil using pitmoss, characterized in that it comprises a.

In step ii), since the initial pH of the general soil is 3 to 4, an appropriate amount of quicklime (CaO) or calcium carbonate (CaCO ₃ ) is added to adjust pH 6.0 to 7.5, which is an optimal habitat condition of microorganisms. In this case, the amount of quicklime (CaO) or calcium carbonate (CaCO ₃ ) added to the soil depends on the initial pH value of the general soil.

Pitmos used as an oil adsorbent in the step iii) is prepared by modifying pitmos originally having hydrophilicity to have lipophilic properties.

The oil adsorbent using peat moss used in the present invention has an organic material content of 97% by weight, and is a brown to dark brown fine granular material with a spraying density of 250 to 300 kg / m 3. In the present invention, the peat moss used as an oil adsorbent uses pit moss produced in the region of Pale Moss, Russia, because the oil absorption amount of the oil adsorbent processed with peat moss collected in Canada is about 4 times its own weight. In contrast, oil adsorbents processed from peat moss from Russia have the ability to adsorb oil up to six to eight times their own weight.

The amount of oil adsorbent added to the soil is mixed with contaminated soil by adding 20 to 60% by weight of the contaminated oil. The amount of oil adsorbent is contaminated in case of bunker-C oil and general waste oil depending on the type of pollutant. 30 to 60% by weight of the oil, and 20 to 40% by weight of the contaminated oil in the case of diesel and engine oil, respectively. In this case, when the amount of the oil adsorbent to be added to the soil is less than the range of the input amount, the oil contaminated with the soil is not sufficiently adsorbed to the oil adsorbent, and if it is added beyond the range of the input amount, the economical efficiency is reduced.

In the step iii), the indigenous microorganisms are microorganisms that decompose oil and restore soil, and the types thereof are Pseudomonas sp. , Rhodococcuc sp. , And Flavobacterium sp. Fusarium sp. , Pocclimuces sp .

The optimum growth conditions of the indigenous microorganisms include soil pH of 6.0 to 7.5, humidity of 60 to 80%, temperature of 8 ° C or higher, but generally high activity at 25 to 35 ° C. The indigenous microorganisms become active and propagate well when the nutrients such as nitrogen, phosphorus and potassium are supplied sufficiently.

The nutrient medium to be added to the soil in the step iii) is a compound fertilizer such as compounding fertilizer, chemical fertilizer, etc., which is generally commercially available in the market, and 18 to 22 kg is added to 1 m 3 of soil. When it is less than ㎏, the activity of indigenous microorganisms that break down oil is not enough, and soil restoration is not performed smoothly. When the input amount exceeds 22 kg, the pH of the soil rises, so the optimum habitat condition of indigenous microorganism is not achieved. Do not.

Corrosion accelerators and potassium corrosion accelerators and sodium corrosion promoters are used alternately once a month. The role of corrosion promoters is alkali extracts from peat with high degradability and high humic acid content (about 60% by weight of dry matter), the biologically active carbon double bonds, active groups, essential amino acids and lipid bonds of these extracts. Contribute to this enrichment.

In this case, the amount of corrosion accelerator to be added to the soil is 45 to 55 g per 1 m 3 of soil. When the amount is less than 45 g, the rate of decomposition of microorganisms in oil decreases, and when the amount exceeds 55 g. The rate of oil decomposition no longer increases significantly.

     These corrosion promoters include sodium and potassium, the chemical composition of which is shown in the following Table 1, and sodium promotes the growth of living organisms and terrestrial higher plants, and potassium increases the growth of plant roots. Promotes actively.

TABLE 1

division Content (% by weight) Sodium type Potassium type Organic matter 91.28 90.81 Fe ₂ O ₃ 0.25 0.50 Al ₂ O ₃ 0.67 1.32 CaO 0.13 0.18 MgO 0.10 0.23 Na ₂ O 5.54 0.35 K ₂ O 0.08 4.71 Other 1.95 1.90 system 100.0 100.0

The step iii) is about 10 days after the step iii), in which case the pH of the soil is lowered, which means that the microorganisms in the soil are activated. In order to adjust to the quick lime (CaO) is added again according to the method of step ii). When the nutrient medium is added to the soil, the pH of the soil is lowered. At this time, the soil is sprayed with water to control the pH of the soil. In addition, when the pH of the soil is lower than 5.0 and the fertilization index is 3.5 or more, calcium carbonate (CaCO ₃ ) is used instead of quicklime (CaO).

Step iii) may be repeated several times until the restoration of the soil, depending on the conditions of the contaminated soil and the activation of microorganisms.

In step iii), the soil is inverted twice a month to supply oxygen to the oil oxidizing microorganism, and the nutrient medium and the corrosion promoter are administered according to the method of step iii) about once a month.

Typically, the fertility index rises over time. When the fertilization index is 3.0 or more, the soil restoration is considered complete, and when the fertilization index is 4.0 or more, the fertilization index is lowered to 3.0 by spraying water. The complete restoration of the soil according to the invention takes about 60 days.

The biological restoration method of the oil-contaminated soil using the peat moss is applicable not only in the soil but also in the ocean, and when applied to the seabed of the ocean, the process of inverting the soil of step iii) is omitted.

The theoretical dose of oil adsorbent using peat moss according to the present invention is shown in Table 2 below. However, the amount of oil adsorbent actually used is mixed by adding enough oil to adsorb the oil so that oil does not come out when the soil is touched by hand.

TABLE 2

division Oil Adsorbent Input (kg / kg of Oil) Sodium corrosion accelerator (g / ㎥) Nutrient medium (fertilizer) (㎏ / ㎥) B-C oil 0.3 to 0.6 45 to 55 18 to 22 Via 0.2 to 0.4 45 to 55 18 to 22 Engine oil 0.2 to 0.4 45 to 55 18 to 22 Waste oil 0.3 to 0.6 45 to 55 18 to 22

Hereinafter, the present invention will be described in detail with reference to Examples.

(Examples 1 and 2 and Comparative Examples 1 and 2)

Example 1 Loam Layer Area

Ⅰ) Contamination of 100kg diesel oil to 1ton (0.48㎥) of loam with specific gravity 2.1: (average pollution 100mg diesel oil / 1g loam)

Ii) measuring diesel pollution and initial fertilization index of the contaminated soil;

Iii) adjusting the pH of the soil by adding quicklime (CaO) so that the pH of the soil is 7;

Iii) crushing 20 kg of oil adsorbent to mix with contaminated loam;

Iii) crushing the soil with 9 kg of nutrient medium and 22 g of corrosion promoter;

Iv) inverting and crushing the loam at 20-day intervals, and administering the nutrient medium and the corrosion promoter in liquid form to measure the pH to maintain a value of 7;

The experiment was carried out for 60 days, and the measurement was performed at 10 day intervals.

Example 2 Sand Layer Area

Iii) contaminating 60 kg of diesel oil with 1 ton (0.56 m 3) of sand having a specific gravity of 1.8; (Average pollution 60mg diesel / 1g sand)

Ii) measuring diesel pollution and initial fertilization index of the contaminated soil;

Iii) adjusting the pH of the soil by adding quicklime (CaO) so that the pH of the soil is 7;

Iii) crushing 24 kg of oil adsorbent to mix with contaminated sand;

V) administering 12 kg of nutrient medium and 31 g of corrosion promoter and crushing the sand;

Iii) inverting and crushing the sand at 20 day intervals, and administering the nutrient medium and the corrosion promoter in the liquid phase so as to measure the pH to maintain the measured value of 7;

The experiment was carried out for 60 days, and the measurement was performed at 10 day intervals.

Comparative Example 1 Loam Layer Area

According to the same method as in Example 1, a conventional oil adsorbent using pitmoss was administered, and no nutrient medium and a corrosion accelerator were administered.

Comparative Example 2: Sand Layer Area

According to the same method as in Example 2, a conventional oil adsorbent using pitmos was administered, and a nutrient medium and a corrosion accelerator were not administered.

TABLE 3

division Hours 0 10 20 30 40 50 60 Example Diesel pollution One 100.0 95.4 81.1 50.8 37.6 11.2 0.9 2 60.3 53.6 40.0 20.2 15.4 5.1 1.0 pH One 4.0 4.8 5.3 5.8 6.0 6.3 6.5 2 3.8 4.0 4.5 5.0 5.7 5.8 6.0 Fertility index One 0.21 0.25 0.61 1.00 1.82 2.16 2.50 2 0.46 0.61 1.42 2.00 2.51 2.63 2.74 Comparative example Diesel pollution One 100.0 95.3 93.8 92.5 92.2 91.5 90.1 2 60.3 58.5 57.3 56.1 52.7 52.2 51.8 pH One 4.0 4.0 4.1 4.2 4.1 4.2 4.3 2 3.8 3.9 3.9 4.0 4.1 4.1 4.2 Fertility index One 0.21 0.22 0.21 0.23 0.23 0.24 0.26 2 0.46 0.48 0.48 0.47 0.48 0.50 0.50

* Diesel pollution

Example 1 and Comparative Example 1: mg number of diesel oil contained per 1 g of loam

Example 2 and Comparative Example 2: mg number of light oil contained per 1 g of sand

1) diesel pollution

Analysis of the diesel fuel concentration in the soil samples was measured by weight of carbon tetrachloride extracted. Component analysis of the extracted hydrocarbons was carried out using a device of gas chromatography GC-7A (column filler 5% SE-30).

At the time of extraction, organic compounds (such as soil lipids) in the soil entered the solution in addition to the hydrocarbons of the diesel fuel. Samples were prepared to rule out the effects of the hydrocarbons, including uncontaminated soils and oil adsorbents and soil added in proportion to corrosion promoters in the two regions. The amount of soil hydrocarbons is calculated by subtracting the total amount of hydrocarbons in the quantity from the diesel.

2) pH

Measure with a pH meter. The measurement method is to add a small amount of distilled water to the sample taken from the contaminated soil, make it into a thin porridge, and measure it with a pH meter.

3) fertility index

Salted soils with fertility index> 3.5

Fertility Index = 3.0 to 3.5 Optimum Nutritional Status

Fertility Index = 2.5-3.0 moderate fertilized soil conditions

Fertility index = 2.0-2.5 poor soil conditions;

Fertility index <2 very poor soil conditions

Oxidation Index = 7 Neutral Soil (index of oxidation index corresponds to pH of aqueous extract).

As shown in [Table 3], in the case of Examples 1 and 2, the soil after 60 days showed a moderate fertilized soil state with a fertility index of 2.5 or more, and Example 2 was used for The biological reconstruction method provides a smooth oxygen supply, resulting in a better fertilization index than the loam layer of Example 1. However, Comparative Examples 1 and 2 did not apply the biological restoration method of the oil-contaminated soil according to the present invention showed a level of a slight increase in fertility index over time.

In addition, the diesel pollution degree showing the change in the diesel decomposition of the soil and the treated soil after the contaminated soil restoration method of the present invention, after 60 days, the diesel pollution in the soil in the two regions of Examples 1 and 2, respectively 0.9, 1.0, 99.1% and 98.3% of the gasoline decomposition results compared to the initial gasoline pollution degree, which was much better than the 9.9% and 14.1% gasoline decomposition results of the regions of Comparative Examples 1 and 2.

The present invention exhibits excellent adsorptive power from contaminated soil using pitmoss that adsorbs oil, etc., and rapidly adsorbs oil, etc., in particular, by activating indigenous oil oxidizing microorganisms using nutrient medium and corrosion promoter, It is a method of restoring polluted soils that biologically decomposes the back, and it is excellent in the decomposition effect of oil even in various soil environments, so that the soil can be restored in a short time, thereby minimizing the loss of economic activity area. Since it plays a role as an excellent manure after the final restoration to the material, it is not only environmentally friendly but also does not incur secondary treatment costs, thereby reducing costs.

Claims (5)

In the biological restoration method of oil-contaminated soil using pitmos, Iii) measuring the oil concentration of the contaminated soil and the initial fertility index (nutritionality) of the soil; Ii) adjusting the pH of the soil by adding quicklime (CaO) or calcium carbonate (CaCO ₃ ) so that the pH of the soil is 7; Iii) mixing 20 to 60% by weight of the oil adsorbent made of pitmoss with the contaminated soil; Iii) adding 18-22 kg of nutrient medium and 45-55 g of corrosion promoter to 1 m 3 of soil for activation of indigenous oil oxidizing microorganisms inhabiting contaminated soil; Iii) re-adjusting the pH of the soil so that the pH of the soil is set to 7 by adding CaO to the soil in the same manner as in step ii); Iii) inverting the soil twice a month to supply sufficient oxygen to the indigenous oil oxidizing microorganisms and injecting the nutrient medium and the corrosion promoter according to the method of step iv) from time to time so that the pH of the soil is maintained; Biological restoration method of oil-contaminated soil using peat moss comprising a. The method of claim 1, wherein the amount of the oil adsorbent in step (iii) is bunker-C oil and general waste oil 30 to 60% by weight of the contaminated oil amount of the biological restoration method of the soil soiled using peat moss . The method of claim 1, wherein the amount of the oil adsorbent in step (iii) is 20 to 40% by weight of the contaminated oil in the case of diesel oil and engine oil. The method of claim 1, wherein the corrosion accelerator in step (iii) is a biological restoration method of the oil-contaminated soil using pitmos, characterized in that the potassium-based corrosion promoter and sodium-based corrosion promoter is introduced alternately about once a month. delete