JP4220893B2 - Soil purification transpiration equipment for sludge water - Google Patents

Description

The present invention relates to an apparatus and a method for evaporating digestive juice after subjecting organic sludge water such as livestock waste to soil purification treatment. Specifically, the digestion after the organic sludge water is treated by methane fermentation by the action of soil fungi that inhabit the soil, and then the SS component, which is suspended suspended matter such as straw and wood chips, is dehydrated and removed. The present invention relates to a soil purification transpiration apparatus and a soil purification transpiration method for evaporating liquid into the atmosphere.

The soil purification layer uses a digestion and decomposition function of organic carbohydrates or nitrogen compounds by small animals and soil fungi in the soil, and can effectively remove phosphorus and nitrogen by suppressing malodor. It is a method that can achieve purification of sludge water at low cost.

On the other hand, it has been proposed to purify contaminated soil using digestion and decomposition functions by soil bacteria contained in the soil (Patent Document 1). That is, a means for supplying air to the soil and a heat generating means for raising the temperature of the air are provided, and heated hot air is injected into the soil to raise the temperature of the soil and supply oxygen. . In this way, soil fungi are activated by keeping the soil at a desired temperature. Further, by supplying oxygen, the reduced oxygen concentration can be maintained, and the function of soil fungus can always be activated. Thus, since the heat generating means for raising the temperature of the air is provided in the soil, the combination of the soil, the air supply means and the means for heating the soil seems to be similar to the configuration of the present invention described later. However, the means according to Patent Document 1 includes means for supplying air into the soil, whereas the configuration of the present invention is different in that it includes means for discharging steam from the soil side to the atmosphere. . Further, the object to be purified is different, and the purpose of this document 1 is to purify the soil, whereas the present invention is different in that the present invention purifies and evaporates sludge water.

In addition, while the soil purification method of Patent Document 1 described above purifies contaminated soil using digestion and decomposition functions by soil fungi, on the other hand, in order to purify sludge water, small animals and soil in the soil It has been proposed to use digestion and degradation functions by bacteria (Patent Document 2). That is, according to the soil purification method described in this document, it can be used as a purification means particularly in an area where the sewerage system is not complete, or in an area where discharge is prohibited or restricted. In this method, there is a problem that organic matter is easily clogged in the soil layer and the purification function of sludge water is reduced. Therefore, a means of supplying air to the soil layer and keeping it in an aerobic state is adopted.

JP 2000-237737 A JP-A-9-122668

However, the means by patent document 2 is making the digestive liquid after performing a soil purification process osmose | permeate groundwater. There is a problem in adopting it nowadays, as groundwater is polluted as it continues for a long time, and environmental regulations have become stricter.

Conventionally, digested liquid after methane fermentation of organic sludge water such as livestock waste has been processed in farmland reduction and wastewater treatment facilities, but the former requires a vast farmland, so the area is limited. In the latter case, because of the high capital investment cost, an inexpensive digestive treatment method is desired.

Therefore, the present invention was made in view of the above circumstances, and provided with means for heating the soil without allowing the digestive liquid after the soil purification treatment to the organic sludge water such as livestock waste to permeate the groundwater, and By providing a means to discharge the steam after the digested liquid is evaporated, the digested liquid is converted to steam and evaporated to the atmosphere, and simple soil purification transpiration that does not require sludge water drainage facilities An object is to provide a device and a soil purification transpiration method.

In order to achieve the above object, the claimed invention is a soil purification and transpiration apparatus that circulates digestive juice after organic sludge water has been subjected to soil purification, and surrounds the gravel layer with an impervious wall, A fine-grained layer is laminated thereon, a porous tube is embedded in the fine-grained layer, a suction fan is provided at the end of the porous tube, and a water conduit is buried under the gravel layer. A digestion fluid transpiration transpiration apparatus comprising a plurality of outlets in a longitudinal direction of a water conduit, a water inlet at a distal end of the water conduit, a water tank at a terminal, and a pump at the water tank. It is. About these things, a structure and an effect | action are described in Example 1, or the structure is shown in FIG.

Here, “digestion liquid” as used in this specification refers to the SS content which is suspended suspended matter such as straw and wood chips after subjecting organic sludge water such as livestock waste to methane fermentation treatment with soil fungi. A liquid containing the BOD content after dehydration and removal.

“Transpiration” means that moisture in the soil is heated to be vaporized and released into the atmosphere.

An “impermeable wall” is a wall that separates the soil layer from the gravel layer, and the soil layer prevents the water from leaking into or penetrating the soil layer and the gravel layer through this wall. It is a film or wall having a function of cutting the edge between the gravels and the gravel layer. It is not always necessary to have a thickness.

The “dome” is an enclosure that covers the upper part of the fine-grained layer, and functions to prevent rain from leaking into and entering through the enclosure, and the shape is not necessarily circular but may be square.

The present invention is a method of decomposing organic matter contained in organic sludge water such as livestock waste by the action of soil fungi that inhabit the soil, and then evaporating the treated digestive liquid into the atmosphere and evaporating it. The present invention relates to a wastewater treatment apparatus and a treatment method. That is, the present invention relates to a sludge water treatment system that does not require a separate drainage facility. Accordingly, since the digested liquid after the soil purification treatment is not permeated into the groundwater, the groundwater is not polluted, and an effect that matches the recent circumstances in which environmental regulations have become strict is achieved. In particular, it can be used as a purification means in areas where the sewage system is not complete or in areas where discharge is prohibited or restricted, and it can contribute to environmental conservation in these areas. Further, according to the present invention, the equipment cost and the operation maintenance cost are low, and the purification of sludge water can be achieved at a low cost. Normally, a large transpiration area is required to evaporate the wastewater into the soil, but in the present invention, the rate of vaporization and transpiration is accelerated by subjecting the heating wire of the soil and the steam pipe to forced heating or steam suction treatment. Therefore, a practical and compact soil purification transpiration system can be realized without requiring a transpiration area.

In addition, since the soil used for a gravel layer and a fine-grained layer can be reused, a maintenance cost becomes cheap. That is, as the digestive liquid continues to evaporate, soluble salts are deposited in the fine-grained layer, and the evaporating rate decreases. In this case, it can be regenerated by washing the fine-grained layer with water. In addition, the gravel layer is clogged with sludge, flocs, etc., and the decomposition of organic substances and the flow of the processing liquid become slow. In this case, it can be regenerated by washing in the same manner.

Embodiments of the present invention will be specifically described below based on the embodiments of the present invention illustrated in the accompanying drawings.

Embodiments of the present invention will be specifically described below based on the embodiments of the present invention illustrated in the accompanying drawings. First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing an example of an embodiment according to the soil purification and transpiration apparatus of the present invention. FIG. 2 is a cross-sectional view of the above.

As shown in FIGS. 1 and 2, a soil layer 13 is partitioned by an impermeable wall 14, a gravel layer 11 is formed therein, and a fine particle layer 12 is laminated thereon. Here, the impervious wall 14 uses a sheet made of reinforced vinyl chloride. The gravel layer 11 is a porous soil layer having many gaps so that sludge water can easily permeate, and is made of artificial zeolite using coal ash as a raw material. The fine grain layer 12 uses sawdust and mushroom waste culture waste. The water conduit 3 is embedded in the gravel layer 11, and the digested liquid is introduced from the inlet 4 to the lower water conduit 3 embedded in the gravel layer 11. Then, the digested liquid is permeated into the gravel layer 11 from the discharge ports 5 provided at equal intervals in the longitudinal direction of the water conduit 3. In addition, a pipe made of vinyl chloride resin is used for the water guide pipe 3. A plurality of porous tubes 1 are embedded in the upper fine particle layer 12, and the digestive juice is sucked into the fine particle layer and heated to become vapor, which is sucked from the porous tube 1 by the fan 2, and finally the atmosphere. Vaporized and released. The perforated tube 1 uses a plastic mesh tube in order to easily suck the steam heated in the fine particle layer into the tube. In addition, when the transpiration | evaporation speed | rate of the digested liquid thrown in from the inlet 4 is slow and it accumulates in the water storage tank 8, it sucks with the pump 6 from the return port 10, returns to the inlet 4 again, and circulates. Moreover, when the pool water of digestive liquid reaches the upper limit level of a gravel layer, introduction | transduction of digestive liquid is stopped temporarily and it waits for the level fall by transpiration.

It is comprised as mentioned above, Next, an effect | action is demonstrated.

The digested liquid that has penetrated into the gravel layer 11 from the conduit 3 is digested by the action of aerobic or anaerobic soil fungi present in the gravel layer while passing through a layer thickness of about 600 mm for 1 to 3 weeks. Decompose remaining organic matter in the liquid. That is, the BOD content, COD content, ammonia and other organic substances in the digestive juice are decomposed, purified, or odor components are simultaneously decomposed. After that, due to the capillary phenomenon of the fine-grained layer 12, the digested liquid after the organic matter permeating into the gravel layer 11 is decomposed is sucked up, and the residual organic matter and odor are decomposed by the soil bacteria that are inhabited. . The digested liquid sucked up into the fine-grained layer 12 is vaporized by the heat of fermentation by the soil bacteria in the fine-grained layer 12. Alternatively, the digestive juice is vaporized by solar heat during the daytime. The generated steam is sucked by the fan 2 from the perforated pipe 1 embedded in the fine-grained layer 12, and is released into the atmosphere and evaporated.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a cross-sectional view showing an example of an embodiment according to a soil purification transpiration apparatus. FIG. 4 shows the test results of transpiration by forced heating and natural transpiration.

The main difference between the present embodiment and the first embodiment is that vaporization of digestive juice is promoted by embedding a heat tube as a heat source in the fine-grained layer.

As shown in FIG. 3, the soil is obtained by partitioning the soil layer 13 with an impermeable wall 14 and laminating a gravel layer 11 and a fine particle layer 12 on top thereof. A plurality of heat tubes 7 are arranged in parallel with the porous tube 1 embedded in the fine particle layer 12. Others are the same as in the first embodiment.

The configuration and testing are as described above. Next, the operation will be described.

Normally, the digestive juice sucked up into the fine-grained layer 12 is vaporized by the heat of fermentation by the soil bacteria in the fine-grained layer 12. Or it is vaporized by solar heat in the daytime. The generated steam is sucked from the perforated tube 1 embedded in the fine-grained layer 12 by the fan 2 including a vacuum pump, and is released into the atmosphere and evaporated. However, the vaporization of the digestive juice was promoted by providing a separate heat source in this embodiment, assuming that the outside air is high in humidity and the vaporization rate is slow or the amount of heat such as solar heat is insufficient. The heat pipe 7 as a heat source uses a heating wire or a steam pipe. The same applies to the following embodiments. The vaporization of the digestive fluid that has penetrated into the fine-grained layer 12 is promoted by these heats.

Details of the test examples related to this example will be described. In this test, horticultural red jade soil in which the fine-grained layer 12 and gravel layer 11 are mixed is used as the test soil, and the effect of transpiration by forced heating is confirmed. Here, the horticultural red jade soil has an average particle size of 3.4 mm and a moisture content of 27.5%. The water content of the soil was adjusted by adding 750 g of water per 1 kg of horticultural red jade soil. The adjusted soil is put into a container having a cross section of 160 mm short side and 410 mm long side. Then, a 50 mm diameter net pipe is penetrated in the longitudinal direction as a perforated pipe 1 50 mm below the upper surface of the short side of the container, and one end of the net pipe is closed. In addition, an electric heater with a temperature adjusting function is embedded as a heat pipe 7 at a distance of 10 mm in parallel with the net pipe. A vacuum pump is provided as a suction fan 2 at the open end of the net pipe. Here, the thermometer for a test was set in the surface layer part of the horticultural red crust.

The test was performed by the following method using the above test apparatus. That is, the room temperature was 26 ° C., the humidity was 30 to 37%, the suction amount from the vacuum pump was 13 liters / minute, and the temperature adjustment of the electric heater was set to 30 to 35 ° C. In this state, the amount of water sucked from the open end of the net pipe was set as the transpiration amount g and the transpiration rate g / m 2 · hour, and was weighed every 30 minutes using an electronic balance.

The test results are shown in Table 1 and FIG. 4 as test results by transpiration by forced heating and natural transpiration. Here, the natural transpiration in Table 1 and FIG. 4 means that water is vaporized and transpiration by room temperature or heat of fermentation by soil bacteria. The forced transpiration means that the water is vaporized and evaporated by forced heating by the electric heater of this test example, and the water sucked by a fan consisting of a vacuum pump through a porous tube was measured as the amount of forced transpiration. In the case of transpiration of forced heating by the electric heater of this test example, the transpiration effect about 4 times that of natural transpiration was recognized.

Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a cross-sectional view showing an example of an embodiment according to a soil purification transpiration apparatus. FIG. 6 is a cross-sectional view of the above.

The main difference between this embodiment and the second embodiment is that the upper part of the fine-grained layer is covered with a dome to promote the vaporization of the digestive juice.

As shown in FIG. 5 and FIG. 6, the soil is obtained by dividing the soil layer 13 with an impervious wall 14 and laminating a gravel layer 11 and a fine-grained layer 12 thereon. A plurality of heat tubes 7 are arranged in parallel with the porous tube 1 embedded in the fine particle layer 12. Then, the upper part of the fine grain layer 12 is covered with the dome 9. The dome 9 uses a drip-proof vinyl chloride resin film to prevent rainwater from penetrating. Others are the same as in the second embodiment.

It is comprised as mentioned above, Next, an effect | action is demonstrated.

Usually, the digested liquid sucked up into the fine-grained layer 12 generates heat due to fermentation by the soil bacteria in the fine-grained layer 12, and the digested liquid is vaporized. Or it is vaporized by solar heat in the daytime. The generated steam is sucked by the fan 2 from the perforated pipe 1 embedded in the fine-grained layer 12, and is released into the atmosphere and evaporated. However, when these calories are insufficient, a separate heat source is provided as described above to promote the vaporization of the digestive juice. A heating wire or steam is confined in the heat tube 7 as a heat source. Furthermore, in order to increase the vaporization efficiency of the digestive liquid, in addition to the above heat source, by covering the upper part of the fine particle layer 12 with the dome 9, solar heat can be taken into the dome as a heat source, Vaporization and transpiration are promoted.

As described in the above examples, examples of the heat source for vaporizing the digested liquid that has permeated the fine-grained layer 12 include fermentation by soil fungi, solar heat, heating wires, steam tubes, and solar heat taken into the dome. According to the present invention, an efficient soil purification and transpiration system can be operated by appropriately combining these heat sources according to weather conditions such as humidity.

In addition, as another effect of the dome, it is possible to prevent rainwater from entering due to rain, so that rainwater does not enter the digestive fluid and become groundwater, thereby polluting the environment.

In each Example, organic sludge water, such as livestock waste, was demonstrated. However, it is not always necessary to limit to these. This contributes to the purification of BOD-treated wastewater for the decomposition of organic waste such as daily life and food, and further to the elimination of wastewater.

It is sectional drawing which shows an example of embodiment which concerns on the soil purification transpiration apparatus of this invention. It is a cross-sectional view same as the above. It is sectional drawing which shows the other example of embodiment which concerns on the soil purification transpiration apparatus of this invention. It is a diagram which shows the test result by transpiration by forced heating and natural transpiration. It is sectional drawing which shows the other example of embodiment which concerns on the soil purification transpiration apparatus of this invention. It is a cross-sectional view same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Porous pipe 2 Fan 3 Conduit pipe 4 Inlet 5 Outlet 6 Pump 7 Heat pipe 8 Water tank 9 Dome 10 Return port 11 Gravel layer 12 Fine grain layer 13 Soil layer 14 Impervious wall

Claims (1)

In the soil purification transpiration device that circulates the digested liquid after organic soil sludge purification,
Surround the gravel layer with an impervious wall,
A fine grain layer is laminated on this gravel layer,
A porous tube is embedded in the fine particle layer,
A suction fan is provided at the end of the perforated tube,
And, a conduit pipe is embedded in the lower layer of the gravel layer, and a plurality of outlets are provided in the longitudinal direction,
Provided with an inlet at the tip of the water conduit and with a water storage tank at the end,
A digestion fluid transpiration transpiration apparatus characterized by comprising a pump in this water tank.

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