JP2016010780A - Apparatus for purifying soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for purifying soil, in which a problem of foul smell is solved in bioremediation for purifying oil-containing soil by microorganisms.SOLUTION: An apparatus 1 for purifying soil includes a purification body part 2, an air supply system 3 and an exhaust system 5. The purification body part 2 includes a plurality of septic tanks 2a. Microorganism-introduced oil-containing soil is housed in each of the septic tanks 2a. Air is supplied to the oil-containing soil of each of the septic tanks 2a from the air supply system 3. An opening 2c of each of the septic tanks 2a is closed by a top cover 2b. Gas in the space R formed in the upper part of each of the septic tanks 2a is discharged to the outside by the exhaust system 5. An adsorption column 5c is connected to the exhaust system 5 so that foul smell substances in the gas in the space R of each of the septic tanks 2a are adsorbed. As a result, the problem of foul smell in the bioremediation for purifying the soil can be solved.

Description

  The present invention relates to a soil purification apparatus, for example, a biological purification technique (bioremediation) for purifying oil-containing soil with microorganisms.

  Bioremediation is a technology that decomposes harmful substances in the soil into harmless substances such as carbon dioxide and water using microorganisms. It is environmentally friendly and costs less than other methods such as cleaning and heating. It is also practically used as a purification method for oil-containing soils because of its low cost.

  In particular, land farming (solid-phase treatment), which is one of the bioremediation methods, is an advantageous method for purifying oil-containing soils because it has good workability and manageability and is less expensive than other methods. It is used a lot.

  In this land farming, for example, after excavating oil-containing soil and embankment on the ground, microorganisms and nutrient salts excellent in oil content decomposition are sprayed on the embankment, and the embankment is periodically stirred by heavy machinery. By keeping the soil in an aerobic condition, the indigenous microorganisms and sprayed microorganisms are activated and the oil is decomposed.

  In addition, about the soil purification technique by bioremediation, there exists description in patent document 1, 2, for example. Patent Document 1 discloses types of microorganisms suitable for purification of oil-containing soil. Patent Document 2 discloses that after impregnating contaminated soil having poor water permeability in situ, a nutrient solution for microorganisms is supplied to the contaminated soil, and the contaminated soil region is covered with a vinyl sheet or the like to remove anaerobic microorganisms. A soil purification method for activating and purifying contaminated soil is disclosed.

JP 2009-291679 A JP 2006-122880 A

  However, when applying bioremediation, it is necessary to fully study its characteristics and applicability, find out the optimal management conditions, and implement, for example, the amount of nutrients added to contaminated soil, Depending on the type, a strange odor such as ammonia odor or spoilage odor is generated during the decomposition of harmful substances by microorganisms, which may greatly affect the surrounding environment.

  The present invention has been made from the above technical background, and its purpose is to provide a technique capable of preventing the problem of off-flavor in bioremediation for purifying oil-containing soil with microorganisms. To do.

  In order to solve the above-mentioned problem, the soil purification apparatus of the present invention according to claim 1 includes a container for storing oil-containing soil into which microorganisms that decompose oil are introduced, and a lid that opens and closes the opening of the container. A purification main body comprising a portion; an air supply means for supplying air into the oil-containing soil in the container; an exhaust means for discharging the gas in the container to the outside; and the exhaust means connected to the container. It is characterized by comprising a capturing means for capturing the off-flavor substance inside, and a drain means for discharging the water in the container.

  The present invention according to claim 2 is the invention according to claim 1, wherein the air supply means includes an air supply pipe provided on a bottom surface in the container, and the air supply pipe, the oil-containing soil, An air supply pipe protecting member for protecting the air supply pipe is provided between the two.

  Moreover, the present invention according to claim 3 is the invention according to claim 1 or 2, wherein the drainage means includes a drainage portion provided on a bottom surface in the container, and the drainage portion and the oil-containing soil. A drainage protection member for protecting the drainage is provided between the two.

  Further, the present invention according to claim 4 is the invention according to claim 1, 2, or 3, wherein the purification main body is provided with a plurality of the containers adjacent to each other in the first direction, The exhaust means includes exhaust holes formed in a wall portion of the container so as to communicate with the chambers of the plurality of containers, and the exhaust holes are adjacent to each other in the first direction. It arrange | positions so that it may be located in the edge part side mutually opposite of the 2nd direction which cross | intersects a direction.

  According to the first aspect of the present invention, it is possible to prevent the problem of off-flavor in bioremediation that purifies oil-containing soil with microorganisms.

  According to invention of Claim 2, it becomes possible to protect the supply pipe in the container which comprises a soil purification apparatus.

  According to invention of Claim 3, it becomes possible to protect the drainage part in the container which comprises a soil purification apparatus.

  According to invention of Claim 4, it becomes possible to improve the exhaustibility of the gas in each chamber | room of a some container.

It is a top view of an example of the soil purification apparatus which concerns on one embodiment of this invention. It is a top view which shows an example of the exhaust route of the soil purification apparatus of FIG. It is the top view which extracted and showed one of the septic tanks which comprise the soil purification apparatus of FIG. (A) is sectional drawing of the II line | wire of FIG. 3, (b) is a side view by the side of the short side of the septic tank of FIG. It is sectional drawing of the II-II line | wire of FIG. It is an expanded sectional view of area | region A1 of FIG. (A) is explanatory drawing in a soil purification process, (b) is explanatory drawing in the soil purification process following Fig.7 (a). (A) is explanatory drawing in the soil purification process following FIG.7 (b), (b) is explanatory drawing in the soil purification process following Fig.8 (a).

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted. “Oil-containing soil” means crude oil, heavy oil, light oil, kerosene, gasoline, lubricating oil, cutting oil, hydraulic oil, rolling oil, insulating oil, engine oil, gear oil, grease, etc. For example, coastal sand and soil contaminated with oil, soil contaminated with oil-contaminated factories and gas stations, soil and oil fields of waste disposal sites contaminated with oil Including soil containing petroleum in its natural state such as. “Purification” means reduction or removal of residual oil, oily odor and oil film.

  First, an example of the soil purification apparatus of this Embodiment is demonstrated with reference to FIGS. 1 is a plan view of an example of the soil purification apparatus of the present embodiment, FIG. 2 is a plan view showing an example of an exhaust path of the soil purification apparatus of FIG. 1, and FIG. 3 is a diagram of a septic tank constituting the soil purification apparatus of FIG. FIG. 4 (a) is a cross-sectional view taken along the line II of FIG. 3, FIG. 4 (b) is a side view on the short side of the septic tank of FIG. 3, and FIG. II-II line sectional view, FIG. 6 is an enlarged sectional view of region A1 of FIG. 1 and 3 are plan views, some of which are hatched for easy viewing of the drawings.

  The soil purification apparatus 1 of this Embodiment shown in FIG. 1 is an apparatus which purifies oil-containing soil S (refer FIG. 4 (a) and FIG. 5) using the microorganisms (3 strains) which have the capability to decompose | disassemble oil. And a purification body 2, an air supply system (air supply means) 3, a drainage system (drainage means) 4, and an exhaust system (exhaust means) 5.

  The purification | cleaning main-body part 2 is a main-body part which purifies the oil-containing soil S, and several upper septic tank (container) 2a (refer FIGS. 1-5) and several upper cover (lid part) 2b provided in each septic tank 2a. (See FIG. 4A and FIG. 5). Although not particularly limited, the total length of the purification main body 2 in the first direction (horizontal direction in FIG. 1) is, for example, 11 m68 cm, and the second direction (vertical vertical in FIG. 1) intersecting (orthogonal) the first direction. The total length of (direction) is, for example, 66 cm.

  Each septic tank 2a is a container formed in a rectangular parallelepiped shape or the like for containing the oil-containing soil S, and is installed side by side along the first direction in a state where the long side wall portions thereof are in contact with each other. Moreover, each septic tank 2a diverts the water tank for construction works, for example, and is formed in the mutually same shape and dimension. Although not particularly limited, the length (short side length) of each septic tank 2a in the first direction is, for example, 2 m36 cm, and the height is, for example, 1 m95 cm.

  Each septic tank 2a contains oil-containing soil S as shown in FIG. 4 (a) and FIG. However, the oil-containing soil S is not filled in the septic tank 2a, and is stored in a state where a space R is formed between the oil-containing soil S and the upper lid 2b. Although not specifically limited, the length from the upper part of the septic tank 2a to the upper surface of the oil-containing soil S is, for example, 50 cm.

  Moreover, the opening part 2c is formed in the upper surface of each septic tank 2a. The oil-containing soil S described above is accommodated in or discharged from the septic tank 2a through the opening 2c of each septic tank 2a. In the decomposition process of the oil in the oil-containing soil S by microorganisms, the opening 2c of each septic tank 2a is closed in a state that can be opened and closed by the upper lid 2b. By providing the upper lid 2b in this manner, the off-flavor substances generated when the oil in the oil-containing soil S in each septic tank 2a is decomposed by microorganisms can be confined in the space R and prevented from leaking outside. Moreover, since it is possible to prevent an unexpectedly large amount of rainwater from entering each septic tank 2a, fluctuations in the amount of nutrient salts and the like due to rainwater can be prevented. For this reason, the malfunction which the purification | cleaning efficiency by microorganisms falls by the fluctuation | variation of the quantity of nutrient salt can be prevented.

  As shown in FIG. 6, the upper lid 2 b has a flat lid body 2 b 1 and a frame body 2 b 2 provided near the outer periphery thereof. The lid body 2b1 of the upper lid 2b is formed of, for example, polystyrene foam. The frame body part 2b2 is made of, for example, plastic. In this way, the lid main body 2b1 occupying the majority of the upper lid 2b is formed of lightly foamed polystyrene, and the high strength plastic frame 2b2 is provided on the outer periphery thereof, thereby maintaining the mechanical strength of the upper lid 2b. Since the weight of the upper lid 2b can be reduced, the handling of the upper lid 2b can be facilitated.

  An air supply system 3 shown in FIG. 1 is configured to supply air (oxygen) to microorganisms in the oil-containing soil S in the septic tank 2a, and includes a compressor 3a, a receiver tank 3b, a regulator 3c, and an external supply. A trachea 3d, an internal air supply pipe (supply pipe) 3e, and a plurality of valves 3f1, 3f2, 3f3 are provided.

  The compressor 3a is an air generation source (air supply mechanism) that generates compressed air. The exhaust port of the compressor 3a is mechanically connected to the inlet of the receiver tank 3b through a valve 3f1. The receiver tank 3b is a tank (air supply mechanism) that stores compressed air supplied from the compressor 3a. The receiver tank 3b can supply air having a stable pressure to the septic tank 2a side, and can protect the compressor 3a. The exhaust port of the receiver tank 3b is mechanically connected to the external air supply pipe 3d through the regulator 3c and the valve 3f2 in this order. The regulator 3c is a regulator (air supply mechanism) that adjusts the supply amount of compressed air supplied to the septic tank 2a. The external air supply pipe 3d is an external pipe (air supply mechanism) that mechanically connects the regulator 3c and the internal air supply pipe 3e in each septic tank 2a, and the compressed air sent via the regulator 3c is supplied to each septic tank. It is installed in a branched state so that it can be sent to the internal air supply pipe 3e in 2a. The valves 3f1, 3f2, and 3f3 are components (air supply mechanism units) that open and close each pipe.

  The internal air supply pipe 3e is an internal pipe for supplying the compressed air (oxygen) sent from the external air supply pipe 3d to the microorganisms in the oil-containing soil S in each septic tank 2a. For example, two internal air supply pipes 3e are installed in each septic tank 2a, and are fixed to the bottom surface in each septic tank 2a in a state of extending along the longitudinal direction of each septic tank 2a. The internal air supply pipe 3e is formed of, for example, a hard vinyl chloride pipe, and a plurality of air supply holes penetrating the inside and outside of the pipe are formed on the outer periphery thereof. The compressed air sent from the external air supply pipe 3d to the internal air supply pipe 3e is continuously or intermittently supplied into the oil-containing soil S in each septic tank 2a through the plurality of air supply holes of the internal air supply pipe 3e. It has become. For this reason, in order to include air in the oil-containing soil S, a large-scale operation such as stirring the oil-containing soil S with a heavy machine can be reduced. Moreover, since the use of heavy machinery can be reduced, the generation of noise can also be reduced.

  In addition, the number of the internal air supply pipes 3e installed in each septic tank 2a is not limited to two, and can be variously changed. For example, one or three or more may be used. Further, the internal air supply pipe 3e is not limited to a linear shape, and may be, for example, a shape branched from one to a plurality in each septic tank 2a. Further, the internal air supply pipe 3e is not limited to a vinyl chloride pipe, and can be variously changed. For example, the internal air supply pipe 3e may be formed of metal.

  The drainage system 4 shown in FIG. 1 is a structure for collecting water in the oil-containing soil S in the septic tank 2a (including water generated by the decomposition of oil by microorganisms) and discharging it to the outside of the purification main body 2. , A drainage member (drainage part) 4a, a drainage pipe 4b, and a valve 4c.

  The drainage member 4a is a member that collects moisture in the oil-containing soil S in the septic tank 2a, and forms a drainage path. For example, three drainage members 4a are arranged in each septic tank 2a, and are fixed to the bottom surface in each septic tank 2a so as to extend along the longitudinal direction of each septic tank 2a so as to sandwich the internal air supply pipe 3e. Has been. The drainage member 4a is made of, for example, a porous material, and is mechanically connected to the drainage pipe 4b outside the purification main body 2 at the end of the drainage path. The water in the oil-containing soil S in each septic tank 2a is collected by the drainage member 4a on the bottom surface of each septic tank 2a, and is discharged to the outside of the purification main body 2 through the drain pipe 4b. The valve 4c is a component that opens and closes the drain pipe 4b.

  As shown in FIGS. 4A and 5, the internal air supply pipe 3 e and the drainage member 4 a described above are covered with a protection member (a supply pipe protection member, a drainage part protection member) 8. The protection member 8 is a member that protects the internal air supply pipe 3e and the drainage member 4a, and is provided between the internal air supply pipe 3e and the drainage member 4a and the oil-containing soil S. This protective member 8 is formed, for example, by coating a three-dimensional reticulated filament excellent in elasticity with a nonwoven fabric filter, and (1) strong in compression resistance and impact resistance, and has no significant decrease in drainage. (2) Lightweight, easy to transport and install, (3) Has the same or better performance as crushed stone, (4) Excellent chemical resistance and microbial resistance, etc. ing.

  By providing such a protection member 8, damage to the internal air supply pipe 3e and the drainage member 4a can be prevented. Further, the air supply holes of the internal air supply pipe 3e can be prevented from being blocked by stones, mud, or the like in the oil-containing soil S. For this reason, since air can be supplied in a stable state with respect to the microorganisms in the oil-containing soil S in each septic tank 2a, the growth and activity of the microorganisms can be promoted. Moreover, since it can also prevent that the drain hole of the drainage member 4a is obstruct | occluded by the stone, mud, etc. in the oil-containing soil S, the water | moisture content in the oil-containing soil S in each septic tank 2a is discharge | released favorably outside. be able to.

  The exhaust system 5 shown in FIGS. 1 and 2 is configured to discharge the gas in the space R (see FIGS. 4A and 5) of each septic tank 2a to the outside, and an exhaust pipe (exhaust hole) 5a. And an exhaust blower 5b and an adsorption tower (capturing means) 5c.

  The exhaust pipe 5a is installed in the side wall part of each septic tank 2a so that the space R of each septic tank 2a may be connected. In each exhaust pipe 5a, the exhaust pipes 5a adjacent to each other in the first direction (horizontal direction in FIGS. 1 and 2) are opposite to each other in the second direction (vertical vertical direction in FIGS. 1 and 2). It is arranged to be located in. That is, the several exhaust pipe 5a adjacent to a 1st direction is arrange | positioned at zigzag form. Thereby, as shown in FIG. 2, the gas in the space R of each septic tank 2a can be exhausted evenly. That is, the gas exhaustability in each space R of the plurality of septic tanks 2a can be improved.

  The exhaust pipe 5a of the purification tank 2a at one end in the first direction of the purification main body 2 is mechanically connected to the exhaust blower 5b. The exhaust blower 5b is a device that sucks the gas in the space R of each septic tank 2a outward, and is configured by, for example, an electric blower. By this exhaust blower 5b, the gas in the space R of each septic tank 2a is exhausted continuously or intermittently to the outside of the purification main body 2. The exhaust port of the exhaust blower 5b is mechanically connected to the adsorption tower 5c.

  The adsorption tower 5c is a device that prevents the odorous substance from leaking to the outside by adsorbing the odorous substance in the gas sent from the exhaust blower 5b. Thereby, in each septic tank 2a, the off-flavor substance produced | generated by decomposition | disassembly of the oil in the oil-containing soil S by microorganisms, etc. can be captured in the adsorption tower 5c, Therefore The problem of off-flavor in bioremediation can be prevented. Here, for example, two adsorption towers 5c are mechanically connected in series. Thereby, since the adsorption area of the adsorption tower 5c can be increased compared with the case where the number of the adsorption towers 5c is one, the adsorption performance of the off-flavor substance can be improved. However, the number of adsorption towers 5c is not limited to two, and can be variously changed, and may be one or three or more. For example, activated carbon is used as the adsorbent for each adsorption tower 5c. However, the adsorbent is not limited to activated carbon and can be variously changed. Moreover, you may connect the adsorption tower 5c which has a different adsorbent according to the kind of off-flavor substance in series.

  Next, an example of the soil purification method of the present embodiment will be described with reference to FIGS. 7 and 8 are explanatory diagrams of the soil purification process.

  First, as shown to Fig.7 (a), an operator sprays predetermined quantity microorganisms (three strains) and nutrient salt with respect to the oil containing soil S of the object area | region which purifies soil. As the nutrient salt, for example, ammonium sulfate (nitrogen (N)) and lime superphosphate (phosphorus (P)) are used.

  Subsequently, as shown in FIG. 7 (b), the oil-containing soil S to which the microorganisms and the like are dispersed is stirred by the heavy machine 10 to mix the oil-containing soil S with the microorganisms and nutrients, and then FIG. ), The oil-containing soil S is put into each septic tank 2a through the opening 2c of each septic tank 2a of the soil purification apparatus 1 by the heavy machine 10. Here, without putting the oil-containing soil S into the respective septic tanks 2a, the charging operation is finished when the oil-containing soil S is added to such an extent that a space is formed above the oil-containing soil S.

  Then, as shown in FIG.8 (b), after closing the opening part 2c of each septic tank 2a of the soil purification apparatus 1 with the upper cover 2b, air is sent into the oil-containing soil S in each septic tank 2a by the air supply system 3 At the same time, the gas in the space R of each septic tank 2 a is exhausted to the outside of the purification main body 2 by the exhaust system 5. At this time, in this embodiment, the odorous substances generated by the decomposition of the oil in the oil-containing soil S by microorganisms can be captured in the adsorption tower 5c in each septic tank 2a. Can be prevented.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the embodiment disclosed in this specification is an example in all respects and is limited to the disclosed technology. It is not a thing. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above-described embodiment, but should be construed according to the description of the scope of claims. All modifications are included without departing from the technical scope equivalent to the described technique and the gist of the claims.

  For example, at least one septic tank of the soil purification apparatus is sufficient. Moreover, it is good also as a structure which can move a purification | cleaning main-body part by attaching a wheel to the bottom face of the septic tank which comprises the purification | cleaning main-body part of a soil purification apparatus.

  As described above, the soil purification apparatus according to the present invention is useful for purification of oil-containing soil by microorganisms.

DESCRIPTION OF SYMBOLS 1 Soil purification apparatus 2 Purification | cleaning main-body part 2a Septic tank 2b Upper cover 2b1 Lid main-body part 2b2 Frame part 2c Opening part 3 Air supply system 3a Compressor 3b Receiver tank 3c Regulator 3d External supply pipe 3e Internal supply pipe 3f1, 3f2, 3f3 Valve 4 Drainage System 4a Drainage member 4b Drainage pipe 4c Valve 5 Exhaust system 5a Exhaust pipe 5b Exhaust blower 5c Adsorption tower 8 Protection member 10 Heavy machinery S Oil-containing soil R Space

Claims (4)

A purification body having a container for storing oil-containing soil into which microorganisms that decompose oil are introduced, and a lid for opening and closing the opening of the container;
An air supply means for supplying air into the oil-containing soil in the container;
Exhaust means for exhausting the gas in the container to the outside;
Capture means connected to the exhaust means for capturing off-flavor substances in the container;
Drainage means for draining moisture in the container;
A soil purification apparatus comprising: The air supply means
An air supply pipe provided on the bottom surface in the container;
The soil purification apparatus according to claim 1, wherein an air supply pipe protection member for protecting the air supply pipe is provided between the air supply pipe and the oil-containing soil. The drainage means is
A drainage part provided on the bottom surface in the container,
The soil purification apparatus according to claim 1 or 2, wherein a drainage protection member for protecting the drainage is provided between the drainage and the oil-containing soil. The purification main body includes a plurality of the containers adjacent to each other along the first direction,
The exhaust means includes an exhaust hole formed in a wall portion of the container so as to communicate with the chambers of the plurality of containers.
The exhaust holes are arranged such that the exhaust holes adjacent to each other in the first direction are positioned on opposite end sides in a second direction intersecting the first direction. Item 1. A soil purification apparatus according to item 1, 2 or 3.

Images