KR20040068638A - A Unit type reactor for the remediation of oil-contaminated soil using high efficiency microbial inocula - Google Patents

Abstract

PURPOSE: A unit type reactor for remediation of oil-contaminated soil using high efficiency microbial inocula is provided which is moved and operated conveniently and clears unpredictability and experimental inconvenience by developing a reactor effectively used to evaluate how much degradation efficiency microbial inocula has on contaminants. CONSTITUTION: The unit type reactor comprises a reactor body(100) having a certain shape; a water/nutrient supply tank(210) for storing water and nutrient; a supply pump(220) for supplying the water and nutrient to the reactor body; sprinklers(110) installed on an upper part of the reactor body to spray the water and nutrient onto an inner part of the reactor body by receiving water and nutrient for growing microorganisms from the supply pump; temperature sensors(120) installed in the reactor body to measure temperature inside the reactor; gravel(130) having certain size formed on a lower part of the reactor body and laid down to certain thickness to prevent closing of drainage; a screen(140) installed on an upper part of the gravel to prevent closing of drainage; contaminated soil(150) which is installed on an upper part of the screen, and from which stone and other waste causing mechanical defects are removed; a pipe(160) installed at a lower part of the gravel to supply air coming out of the air compressor and send leachate discharged to the leachate storage tank; an air compressor(230) for supplying air into the pipe to grow microorganisms and biodegrade various oil components; a leachate tank(240) for storing leachate discharged from the pipe; a solenoid valve(250) installed on a certain part of the pipe and operated periodically to discharge leachate of the reactor body and drain leachate while air is not supplied; a controller(170) installed at one side surface of the reactor body and consisted of certain number of timers to control spraying of the sprinklers and air supply time of the air compressor; and microbial inocula included in the contaminated soil to degrade the contaminated soil.

Description

Unit reactor for the remediation of oil-contaminated soil using high efficiency microbial inocula

The present invention relates to an oil contaminated soil recovery tank, and more particularly, to a unit type reactor for oil contaminated soil recovery using a high-efficiency microbial agent.

Conventional techniques for purifying contaminated soil include Land Farming, Bioventing, and SVE (Soil Vapor Extraction), which dig out contaminated soil and spread it on a large site. Contaminants are removed by injecting nutrients and mixing the soil periodically to promote biodegradation.Bioventing method is to inject air and nutrients into the contaminated site to promote the activities of aerobic microorganisms in the soil to decompose contaminants. Say. In addition, the SVE method utilizes the volatility of contaminants, and installs pipes in contaminated soil and extracts the contaminants by forced vacuum suction.

However, the aforementioned conventional methods have various problems. First, the cultivation method requires a large site and causes air pollution when the pollutants are volatile, and the bioventing method and the SVE method have optimal conditions. Operational instability is not easy, so instability of operation occurs depending on soil conditions, and processing efficiency is low. Therefore, most of the soils contaminated with oil and volatile organic compounds are classified as waste and are processed by expensive landfill methods.

In addition, the evaluation of restoration techniques using soil piles so far has focused on the natural reduction of contaminated soils on site without special facilities or installations. In this case, there is a difficulty in managing the discharged leachate, which may cause secondary environmental pollution, and it may be simply manufactured to give a sense of discomfort to nearby residents or managers.

Maintaining proper water content and microbial population habitat in soils is an important factor for soil restoration but not easy when simple lamination is applied. Soil piles have been managed for more than 6 months, reducing site use capacity and having a slow circulation process in terms of recycling of reprocessed soil.

Therefore, the present invention is to solve the problems of the prior art as described above, a reaction tank that can be effectively used when evaluating the degree of decomposition efficiency for contaminants in developing a technology for restoring oil contaminated soil using microorganisms. It is an object of the present invention to provide a short-term soil recovery unit type reactor through a high-efficiency microbial agent, characterized by the convenience of movement and operation, to solve the uncertainties and experimental inconveniences of the existing experimental methods.

1 is a unit reactor according to the present invention.

2 is the result of an embodiment according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: unit reactor 110: sprinkler

120: temperature sensor 130: gravel

140: screen 150: contaminated soil

160: tube 170: controller

210: water / nutrient supply tank 220: supply pump

230: air compressor 240: leachate storage tank

250: solenoid valve

The object of the present invention is a reactor body 100 having a predetermined shape, water / nutrient supply tank 210 which is a place for storing moisture and nutrients, supplying the water and nutrients to the reactor body 100 Pump 220, the sprinkler 110 is provided on the upper portion of the reactor body 100 and receives the moisture and nutrients for the growth of microorganisms from the supply pump 220 and sprinkled in the reactor body 100, the reactor body It is provided in the interior of the temperature sensor 120 for measuring the temperature in the reactor, the lower portion of the reactor body 100 is provided with gravel having a predetermined size to prevent clogging phenomenon of the drainage ( 130, a screen 140 provided on the gravel 130 to prevent clogging of drainage, stones and other wastes provided on the screen 140 and causing mechanical defects are removed. Soil 150, a tube 160 which is provided in the lower part of the gravel and supplies air from the air compressor and sends the leachate discharged to the leachate storage tank, the tube 160 for the microbial growth and biodegradation of various oil components Air compressor 230 to supply air to), the leachate tank 240 for storing the leachate discharged from the tube 160, the leachate of the reactor body 100 is provided in a predetermined portion of the tube 240 The solenoid valve 250, which periodically operates for the discharge and drains the leachate while the air is not supplied, is installed on one side of the reactor body 100, and consists of a predetermined number of timers of the sprinkler 110. The microorganisms included in the controller 170 and the contaminated soil 150 for controlling the water supply and air supply time of the air compressor 230 and decomposing the contaminated soil 150 It is achieved by a unit reactor for oil pollution soil recovery using a high-efficiency microbial agent, characterized in that it comprises.

Details of the above object and technical configuration of the present invention and the effects thereof according to the present invention will be more clearly understood by the following detailed description with reference to the drawings showing preferred embodiments of the present invention.

The present invention consists of a unit reactor design, microbial preparation and reactor operation. Initial TPH (Total Petroleum Hydrocarbon) concentration in the soil was adjusted to 5,855 mg / kg and water was sprayed from a sprinkler to maintain an appropriate water content of 25-30% for microbial growth for 127 days.

As shown in Figure 1, the unit type reactor is largely composed of a reactor body and a reactor peripheral device.

Reactor body 100 is composed of a controller 170, sprinkler 110, temperature sensor 120, contaminated soil 150, screen 140, gravel 130 and microbial agent, the reactor peripheral device is water / Nutrient supply tank 210, supply pump 220, solenoid valve 250, leachate storage tank 240, the air compressor 230.

The reactor body 100 has a predetermined shape, and preferably has a rectangular parallelepiped shape having a thickness of 5 mm, a height of 100 cm, a length of 300 cm, and a width of 150 cm of steel.

The controller 170 is installed on one side of the reactor body 100. The controller includes a timer, and preferably consists of two timers to adjust the sprinkler of the sprinkler 110 and the air supply time of the air compressor 230.

The water / nutrient supply tank 210 is a place for storing moisture and nutrients. Water and nutrients are supplied into the reactor by the sprinkler 110 through the feed pump 220.

The sprinkler 110 is preferably operated for 10 minutes per hour for supplying moisture and nutrients for microbial growth.

In order to maintain the proper water content of the soil, the sprinkler 110 is controlled in a timer of the controller 170 to spray a certain amount of water every day from the top of the reactor 100, but preferably evenly sprayed.

The temperature sensor 120 is installed in the reactor body 100 to measure the temperature in the reactor. The temperature of the reactor is properly maintained using the temperature measured by the temperature sensor 120.

In order to prevent the clogging phenomenon of the drainage, a predetermined thickness of gravel 130 is added to the lower portion of the reactor body 100, preferably, 1 to 3 cm sized gravel is added thereto, and an upper portion of the gravel 130 is provided. Screen 140 is installed to prevent clogging of the drain.

Stones and other wastes that cause mechanical defects on the screen 140 are removed and filled with contaminated soil 150.

In addition, a pipe 160 is formed below the gravel 130 to blow air from the air compressor 230 and to send the leachate discharged to the leachate storage tank 240.

For microbial growth and biodegradation of various oil components, air is supplied evenly in all layers through the pipe 160 installed in the lower layer of the reactor using the air compressor 230.

While the air is not supplied, the leachate is drained through the solenoid valve 250 installed and connected to the pipe 160 and stored in the leachate storage tank 240.

The solenoid valve 250 is periodically operated to discharge the leachate of the reactor 100, the leachate is drained through the valve 250 while the air is not supplied.

The preparation of microbial preparations was carried out in LB (Luria & Bertani) or TSA (Trypic Soy Agar) liquid medium by using the enrichment technique from soil, river water and activated sludge to isolate oil-decomposing microorganisms. Shake culture.

The medium for enrichment culture is incubated for 7-14 days using a liquid medium containing 10% crude oil and 2% n-hexadecane as the only carbon source in the Glucose-MM2 minimum medium. First, 52 species isolated from 75 species were inoculated again with 0.1 ml in 5 ml of MM2 medium added to crude oil, bunker oil, diesel, etc., to check the degradation of each oil.

Pure isolates were cultured in yeast extract peptone dextrose (YEPD), TSA, and MacCongkey solid medium, followed by morphological characterization, Gram staining, and physiological and biochemical properties of Bergey's Mannual of Systematic Bacteriology and API. As a result of using the kit, Pseudomonas, Aeromonas, Bacillus, Acinetobacter and Enterobacteriaceae genus were identified.

The microbial agent added to the reactor is made of powder of purely identified species.

In soil characteristics and sampling, the soil had an equilibrium coefficient of 15, a curvature coefficient of 1.02, showing a distribution of grading, with 12% gravel, 62% coarse sand, 19% fine sand, 7% silt and clay. It is. The porosity was 44%, the specific gravity of soil particles was 2.641, and the dry density was 1.251 g / cm3.

For chemical and microbiological analysis, sample the soil filled in the reactor monthly using a soil collector (2.5 cm ID).

The first sample is taken from each reactor by sampling from two random locations at a depth of 30 cm. Samples were filtered through a sieve (8 mm) and immediately analyzed or stored in glass containers at 4 ° C. for up to 7 days. The amount of soil sampled is about 50g, and it is stored in a clean glass container and immediately pretreated.

Example 1

After filling 4.5㎥ of soil in the unit type reactor, it is maintained at room temperature without microbial preparation to check the decomposition rate of TPH over time.

Example 2

Fill the unit with 4.5㎥ of soil and add 5Kg of powder mixed with 3 kinds of microbial agents (Acinetobacter junii / jonsonii A-1, Acinetobacter baumanii / calcoaceticus N-1, Pseudomonas aerognosa NW-6) Check the degradation rate of TPH.

Example 3

Fill the unit with 4.5㎥ of soil and add 5Kg of powder mixed with 4 kinds of microbial agents (Acinetobacterjunii / jonsonii A-1, Acinetobacter baumanii / calcoaceticus N-1, Pseudomonas aerognosa NW-6, Acinetobacter lwoffii NB-7) Maintain at room temperature to determine the rate of degradation of TPH over time.

The concentration of TPH in Examples 1 to 3 is shown in FIG. 2.

As a result of the test, the treatment efficiency of TPH treated by the present invention increased from 73% to 98% when four microbial agents were added after 127 days, and the time was shortened compared to the existing studies. This means that the unit type reactor developed by the present invention can be treated with excellent efficiency for oil pollution purification.

Therefore, the unit reactor for oil pollution soil restoration using the high-efficiency microbial agent of the present invention has been difficult to apply the bioremediation method using the microbial complex formulation to restore soil contaminated by oil by developing a unit reactor. Aesthetically, the inconvenience of residents, short-term soil restoration through high-efficiency microbial preparation, and easy to move and operate as a unit type.

In addition, it is a useful invention that can help the national economy in terms of increasing the amount of land used and recycling of reprocessed soil, as it is relatively easy to move and operate and restore the soil in a short time.

Claims (3)

In the reactor for oil pollution soil restoration, Reactor body 100 having a predetermined shape; A water / nutrient supply tank 210 which is a place for storing water and nutrients; A supply pump 220 for supplying the water and the nutrients to the reactor body 100; A sprinkler 110 provided at an upper portion of the reactor body 100 and receiving water and nutrients for microbial growth from the supply pump 220 and sprinkling the inside of the reactor body 100; A temperature sensor 120 provided inside the reactor body 100 for measuring a temperature in the reactor; Gravel 130 of a predetermined size is provided in the lower portion of the reactor body 100 and laid in a predetermined thickness in order to prevent clogging of the drainage; A screen 140 provided on an upper portion of the gravel 130 to prevent clogging of the drainage; A contaminated soil 150 provided on the screen 140 and removing the stones and other wastes that cause mechanical defects; A pipe 160 provided below the gravel to supply air from the air compressor and to send the leachate discharged to the leachate storage tank; An air compressor 230 for supplying air to the tube 160 for microbial growth and biodegradation of various oil components; Leachate tank 240 for storing the leachate discharged from the tube 160; A solenoid valve 250 provided at a predetermined portion of the pipe 240 to periodically operate for leachate discharge of the reactor body 100 and allow leachate to be drained while air is not supplied; A controller 170 installed on one side of the reactor body 100 and configured as a predetermined number of timers to adjust the sprinkler of the sprinkler 110 and the air supply time of the air compressor 230; And Oil-contaminated soil restoration unit type reactor using a high-efficiency microbial agent, characterized in that contained in the contaminated soil 150 and comprises a microbial agent for decomposing the contaminated soil (150). The method of claim 1, The reactor body 100 is a unit reactor for oil pollution using a high-efficiency microbial agent, characterized in that it has the shape of a rectangular parallelepiped having a thickness of 5mm of steel, 100cm in height, 300cm in length, 150cm in width. The method of claim 1, The microbial preparation is a powder mixed with Acinetobacter junii / jonsonii A-1, Acinetobacter baumanii / calcoaceticus N-1, Pseudomonas aerognosa NW-6, and Acinetobacter lwoffii NB-7. Unit reactor.