TWI567344B - Method of preprocessing incineration ash - Google Patents

Description

Pretreatment method for incineration ash

The present invention relates to a method in which waste such as incinerated ash (bottom ash: ash, hereinafter referred to as incinerated ash) is landfilled in a final treatment site or as an aggregate or fill material, A technique for pre-treatment of a backfill material or the like before reuse, especially regarding an effective technique suitable for washing off organic matter or heavy metals, salts, etc. or inhibiting dissolution.

For the surrounding residents, the waste disposal site is deeply impressed as a troublesome facility. The sense of uneasiness about the impact on the surrounding environment is deeply rooted, and the construction of the treatment site is difficult to obtain the consent of the residents. For this reason, it has become difficult to build new disposal sites throughout Japan.

In this case, it is proposed to perform various processes (pre-treatment) in which the waste is changed (stabilized) in advance to have a small influence on the surrounding environment before the waste is filled in the final disposal site. In other words, the pretreatment method is a technique in which the organic matter, salts, heavy metals, and the like contained in the landfill waste are artificially stabilized to be difficult to be eluted and safely stored before the landfill.

As such a technique, for example, as disclosed in Patent Document 1, the waste is washed before the landfill. This method is a method of stabilizing waste by washing the waste mechanically and washing off the organic matter or salt contained in the waste. Further, as disclosed in Patent Document 2, the waste is sprinkled and ventilated before landfill, thereby promoting waste stabilization. This method is a method of washing off or insolubilizing organic substances, salts, heavy metals, and the like in waste by watering and aeration. The method is a technique for promoting stabilization of waste.

Further, Patent Document 3 discloses a technique for removing a heavy metal, a dioxin or the like from a self-incinating ash (bottom ash, or bottom ash and fly ash) as a Values are used.

However, as disclosed in the above-mentioned Patent Document 1 and Patent Document 2, the pretreatment method is divided into a case where the waste is pretreated by mechanical cleaning, and the waste is preliminarily sprinkled by watering and aeration. The method of processing. In the mechanical washing method, equipment for washing, power, and treatment of a relatively large amount of washing water are required. On the other hand, in the method of watering and ventilating, the processing load of mechanical equipment and washing water is less than mechanical washing. However, on the other hand, the pretreatment period for stabilizing the waste becomes long. Therefore, in such a method, an increase in the area of the land for performing the pre-processing is incidental.

Thus, the present applicant has proposed a method for treating waste which is used to eliminate the above-described problem (Patent Document 4, Patent Document 5, and Patent Document 6).

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2002-59106

[Patent Document 2] Japanese Patent Laid-Open No. 2006-281006

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2003-53298

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2008-246367

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2009-131757

[Patent Document 61 Japanese Patent Laid-Open Publication No. 2009-241053

The present invention is related to improvements in prior applications.

The present inventors have continued to conduct intensive studies on the pretreatment of incineration ash as waste. The final focus on the pre-treatment effect of the incineration ash and the pre-treatment period are affected by the temperature of the incineration ash during the pre-treatment period.

That is, the effects of the temperature difference between the seasons and the ambient gas temperature on the incineration ash temperature, the pretreatment effect, and the pretreatment treatment are reviewed. The test results are shown below.

The test was carried out in the following manner: in a test tank having a width of 4 m × depth: 4 m × height: 0.4 m, the height was 0.3 m, the density was 1.3 g/cm 3, and the incineration was carried out. Ash, sprinkle water from above (1.3 mm / time × 3 times / day = 4 mm / day), and ventilate from below (linear speed: 2 mm / sec). As shown in Table 1, the process of the ambient gas temperature has a summer period (the average temperature during the period: 29.6 ° C), an autumn period (the average temperature during the period: 10.2 ° C), and a winter period (the average temperature during the period: 7.3 ° C).

test results:

Fig. 1 (A), Fig. 1 (B), and Fig. 1 (C) show temporal changes in ambient gas (air temperature) and incineration ash temperature during the pretreatment test period during the summer, autumn, and winter periods, respectively.

Further, as an index of the pretreatment effect, FIG. 2 shows the value of the conductivity of the oozing water (Electrical conductance (EC), and FIG. 3 shows the concentration of the TOC (total organic carbon) contained in the oozing water.

As shown in FIG. 1(A), FIG. 1(B), and FIG. 1(C), the temperature of the incineration ash substantially changes with the change of the ambient gas temperature, except during the period in which the ambient gas shows abrupt changes. During the winter and during the fall, the following results were found: the incineration ash temperature tends to be higher than the ambient gas temperature after the start of the test; after 10 days from the start of the test, the incineration ash temperature is shifted to a temperature substantially the same as the ambient gas temperature.

Furthermore, as shown in Fig. 2 and Fig. 3, the following results were obtained: during the period, the period in which the average temperature is high (summer period: 29.6 °C) and the period in which the average temperature is low (winter period: 7.3 °C, autumn period: 10.2 °C) The EC value of the oozing water and the TOC concentration vary with time. The EC value of the oozing water is shown to be 1.2 Siemens/meter (S/m) or less, about 30 days in the summer period, and 60 days or more in the winter period during the summer season. The concentration of TOC also showed the same tendency.

From these results, it is taught that the temperature of the incineration ash during the pre-treatment period will affect the pre-treatment effect and the pre-treatment period. The inventors of the present invention finally focused on the influence of the temperature of the incineration ash during the pretreatment process.

The present invention has been made in view of the above matters.

In an area where there is a temperature difference due to seasons, when the ambient gas temperature in the pre-treatment period affects the temperature of the incineration ash, the pre-treatment period or effect of the incineration ash is not the same in each season.

It is an object of the present invention to provide an advantageous pretreatment method for incineration ash, which realizes the salt and heavy metal contained in the incineration ash by effectively maintaining the temperature condition of the incineration ash during the pretreatment process. In a substance such as an organic substance, the substance which is in an easily eluted state in water is eluted, and the substance which is in a state of being difficult to elute in water is hardly melted, and the incineration ash is reformed to a state of high safety.

That is, the present invention is a pretreatment method for incineration ash, and the incineration ash is stored in the pretreatment tank before the incineration ash is buried or used as an aggregate, a fill material, a backfill material, or the like, The pretreatment of the incineration ash for the sprinkling treatment and the aeration treatment is characterized in that the temperature of the incinerated ash is maintained at 20 ° C or more and 60 ° C or less between at least 10 days from the pretreatment.

Further, the present invention is characterized in that the deposition height of the incineration ash from the bottom surface of the pretreatment tank is 0.8 m or more, and the heat generated from the incinerated ash at the initial stage of deposition is held in the pretreatment tank.

Further, the present invention is characterized in that a mat having heat insulating property and water permeability is covered on the deposited incineration ash to suppress a decrease in temperature of the incinerated ash.

Further, the present invention is characterized in that the pre-treatment tank has a bottom wall and a side wall, and the side wall rises from the periphery of the bottom wall, and the bottom wall and the side wall are provided with heat insulation to suppress a temperature drop of the incineration ash. .

Further, the present invention is characterized in that the pre-treatment tank has a bottom wall and a side wall, and the side wall rises from the periphery of the bottom wall, and the incinerated ash is heated from the bottom wall or the side wall to suppress a temperature drop of the incineration ash. .

Further, according to the present invention, the water sprinkling treatment is performed by spraying water from above the pre-treatment tank, and the ventilation processing is performed to flow air upward from the bottom of the pre-treatment tank.

Further, the present invention is characterized in that the temperature of the incineration ash is maintained at 20 ° C or more and 60 ° C or less between at least 40 days from the pretreatment.

According to the present invention, by maintaining the temperature condition of the incineration ash in the pre-treatment period, it is possible to promote the elution of the substance which is easily eluted in the water, and to make the substance which is difficult to elute in the water hard to dissolve. The EC value and TOC concentration of the incineration ash can be reduced in a short period of time.

In the maintenance management of the temperature condition of the incineration ash during the pre-treatment period, the heat generated from the incineration ash at the initial stage of deposition is held in the pre-treatment tank, and the heat is used in an attempt to make the ambient gas temperature It is advantageous to reduce the energy consumption of the heater for maintaining the temperature condition.

The above described features and advantages of the present invention will be more apparent from the following description.

The present invention is provided, for example, in a part of a final treatment field for performing landfill treatment of incineration ash or a part of a place where incineration ash is reused as an aggregate, a filling material, a backfill material, or the like, and a pretreatment apparatus is provided. The pre-processing device is not limited to a fixed device, and a container that can be moved or various configurations that have been conventionally known can be used.

The incineration ash is put into the front tank, and after the input, the density is set and the thickness is set by the excavator.

Then, in the pretreatment of the sprinkling ash and the aeration treatment, the temperature of the incineration ash is maintained at 20° C. or higher and 60° C. or lower for at least 10 days from the pretreatment.

In the pre-position, the elution promotion and the insolubilization are carried out at the same time. Therefore, in order to stabilize the quality of the effluent water at an early stage, the elution is promoted in a range where the concentration of the effluent water is not increased, and the temperature at which the dissolution is difficult is promoted. Settings are necessary. The temperature setting is difficult, but the range of the set temperature of the pre-treatment temperature is set in the following order.

(1) Setting of lower limit value

In the test results (Fig. 2 and Fig. 3) of the conventional method (the pretreatment temperature is affected by the ambient gas temperature), between 7 °C and 29 °C, both the EC value and the TOC concentration are found. When the treatment temperature is high, the EC value of the oozing water and the TOC concentration tend to be lowered. Therefore, it is considered that the temperature at which the dissolution promotion and the insolubilization effect are changed is set within a range from 7 ° C to 29 ° C without affecting the concentration of the bleed water. The evaluation of the concentration of the effluent water is affected by the temperature and the dissolution of the incineration ash is affected by the temperature, and the lower limit of the pretreatment temperature is reviewed.

method:

50 g (wet weight) of incineration ash was sealed and stored in a 1000 ml polyethylene container, and allowed to stand in a thermostat maintained at a temperature of 5 ° C, 20 ° C, 40 ° C, and 80 ° C. After standing for 40 days, 500 ml of distilled water was added and shaken for 6 hours. The EC value and concentration of TOC, Ca, and Na were analyzed for the supernatant (eluate). The analysis results are shown in Fig. 4(A) to Fig. 4(D). .

Analysis of the results:

Temperature range that inhibits dissolution:

In the range of 5 ° C to 40 ° C, it was confirmed that the EC value and the Ca concentration decreased as the pretreatment temperature was increased. Further, from the viewpoint of increasing the ratio of the decrease in the EC value of the effluent water in the range of 7 ° C to 29 ° C as shown by the conventional method, it is considered that the salt such as Ca affects the EC value. The class is difficult to dissolve. From these results, it is expected that the effect of suppressing elution from the incineration ash can be expected by increasing and maintaining the pretreatment temperature in the range of 5 °C to 40 °C.

Temperature range that promotes dissolution in a range where the concentration of exuded water is not affected

In the range of 5 ° C to 40 ° C, it was confirmed that the concentration of TOC and the concentration of Na increased as the pretreatment temperature increased. Na is a salt which affects the EC value, and it is considered that the ratio of the decrease in the EC value of the exuded water increases as the pretreatment temperature increases in the range of 7 ° C to 29 ° C as shown by the conventional method. The promotion of the elution of Na in this case is to promote dissolution in a range in which the concentration of the bleed water is not affected.

Further, in the case of TOC, elution at 20 ° C to 40 ° C is promoted in comparison with 5 ° C at 20 ° C to 40 ° C. From the viewpoint of increasing the ratio of decrease in the TOC concentration of the effluent water in the range of 7 ° C to 29 ° C as shown in the conventional method, it is considered that the promotion of dissolution of the TOC in this case is The elution is promoted in a range in which the TOC concentration of the oozing water is not affected, and it is considered that for TOC, 20 ° C is a lower limit temperature for promoting elution in a range in which the TOC concentration of the oozing water is not affected.

From the above results, the lower limit of the temperature at which the dissolution is promoted and the insoluble solubility is promoted without increasing the concentration of the bleed water is set to 20 °C.

(2) Setting of the upper limit value

From the results of the dissolution test shown in FIG. 4(A) to FIG. 4(D), it is considered that the effect of suppressing the elution of a part of the salt and promoting the elution of TOC with the increase of the temperature is considered to be effective. In the setting range of 60 °C or higher, it is considered that the input energy source is set, and it is considered that it is not the actual setting. The upper limit is 60 °C, but it is considered that the self-heating phenomenon of incineration ash in the pre-treatment period (including heat preservation) In the case of the case of the measure, it is also appropriate to set the pre-treatment temperature by this process. In this case, it is irresistible that the incineration ash has a temperature exceeding 60 °C.

Temperature in the front where heating or adiabatic is required

From the results of the above (1), in order to maintain the effect of the pretreatment, it is considered that the temperature of the incineration ash in the pretreatment process is lower than 20 ° C, and it must be insulated or warmed by the pretreatment tank. Wait, keep the incineration ash temperature above 20 °C.

The above temperature management is performed at least 40 days from the pre-processing, as shown in Fig. 9 and Fig. 10, after 40 days, since the TOC concentration or the EC value is extremely low, the TOC concentration or the EC value is low. Value is advantageous in stability.

However, in the case of having to warm up, from the point of view of efficient energy use, it is irresistible to make the heating period less than 40 days. For example, the heating period may be set from the beginning to at least 10 days. As a basis for the effect, as shown in Fig. 2 and Fig. 3 (there is no point in the figure because no oozing water is obtained), it can be known that the values of the EC value and the TOC concentration during the summer season when the temperature is high are greatly reduced during the initial 10 days. value. On the other hand, the magnitude of the decrease in the values of the EC value and the TOC concentration does not change as compared with the case where the temperature is low after 10 days. From these results, it is important that the initial temperature management, that is, the temperature management at least 10 days from the pre-treatment, is the effect of warming at the initial stage.

On the other hand, heat is generated from incineration ash at the initial stage of landfill. In the pre-stacking stage, the heat generated from the incineration ash is kept in the pre-treatment tank, and the heat is used to reduce the energy consumption of the heater or the like for maintaining the temperature condition depending on the ambient gas temperature. It is advantageous.

As a state in which the heat generated from the incineration ash is held in the pretreatment tank at the initial stage of deposition, the accumulation height of the incineration ash from the bottom surface of the pretreatment tank is 0.8 m or more. If the stacking height of the incineration ash is 0.8 m or more, it is advantageous in suppressing the temperature from the above and maintaining the temperature of the incineration ash, so it is necessary to keep the heat generated from the incineration ash in the pretreatment tank at the initial stage of the accumulation. The thickness of the incinerated ash layer.

However, as shown in Fig. 8, it is observed that the temperature rises in the 0.4 m from the upper layer, and it is considered that the temperature can be maintained at 0.4 m or more by covering the mat with insulation measures such as the above. However, from the viewpoint of efficient pretreatment of incineration ash, the deposition height is set to 0.8 m or more.

In order to maintain the temperature of the incineration ash above 20 ° C and below 60 ° C, in addition to the stacking height of incineration ash of 0.8 m or more, the accumulated incineration ash is covered with heat insulation and water permeability according to the temperature of the ambient gas. The mat is used to suppress the temperature of the incineration ash from decreasing. Alternatively, the bottom wall and the side wall of the pretreatment tank are provided with heat insulation to suppress a decrease in the temperature of the incineration ash.

In this way, it is more advantageous to reduce the energy consumption of the heater or the like for maintaining the temperature condition.

Various materials which are conventionally used can be used as the heat insulating material used for the heat insulating property of the bottom wall or the side wall. As long as the self-heating of the incineration ash can be sufficiently maintained, the material of the heat insulating material and the method of setting the heat insulating material are not limited.

In order to maintain the temperature of the incineration ash above 20 ° C and below 60 ° C, depending on the temperature of the ambient gas, the incineration ash may be heated from the bottom wall or the side wall of the pretreatment tank to suppress the temperature drop of the incineration ash.

In this way, by keeping the self-heating of the incineration ash in the incineration ash layer, the temperature of the incineration ash during the pre-treatment period is maintained within a desired temperature range above the ambient gas temperature, that is, it can be maintained above 20 ° C and 60 ° C or less, and can be effective in the pretreatment of incineration ash.

The incineration ash deposited at a predetermined layer thickness is intermittently sprinkled at a predetermined interval, and when the water is intermittently sprinkled, the incinerated ash is ventilated together. In other words, a predetermined amount of artificial watering and a predetermined flow rate aeration treatment are performed on the incineration ash dispersed to a predetermined density and a predetermined layer thickness.

In this case, ventilation is performed by opposing the direction of water seepage through the sprinkling water in the incineration ash layer downward. The water oozing speed of the sprinkled water passing through the incineration ash layer becomes small as time changes after the start of the sprinkling water, so that the amount of elution of the eluted material into the oozing water is less changed over time, thereby ensuring a stable dissolution state. It is advantageous to ensure high reliability pre-processing quality.

Example

The implementation of this embodiment is shown in FIGS. 5 and 6. The pretreatment apparatus 10 includes a pretreatment tank 12, a sprinkler 14, a venting device 16, a effluent water collecting device 18, and a control device 20.

(pre-processing tank 12)

The pretreatment tank 12 is a steel plate storage tank.

The steel plate storage tank has a body completely composed of a steel plate, and the body body is composed of a bottom wall and a side wall rising from the periphery of the bottom wall. A accommodating space having a width of 4.7 meters, a depth of 7 meters, and a height of 4 meters is formed inside the steel storage tank.

On the bottom wall of the pretreatment tank 12, a urethane foam having a width of 80 cm and a thickness of 15 cm was placed at intervals of 10 cm, and a water collecting and venting groove having a width of 10 cm was disposed at intervals of 90 cm. . A perforated pipe 24 having a nominal diameter of 50 A is used in the water collecting and venting grooves constituting both the venting device 16 and the effluent water collecting device 18. The gravel is loaded to the upper end of the water collecting and venting groove to protect the perforated pipe 24, and a water-venting layer composed of gravel and water collecting and venting grooves is provided on the bottom wall.

(Incineration ash is put into the pretreatment tank 12)

The incinerated ash 26 is carried into the pretreatment tank 12 by a backhoe and dispersed.

The temperature sensor 38 (thermoelectric coupler) is placed at a position of 0.4 m, 0.8 m, and 1.4 m deep from the surface of the incineration ash 26, and the incineration ash is carried in, and when it is carried in 81 t, the loading is completed. At this time, the height of the incineration ash 26 from the upper side of the water-passing layer was 1.8 m, and the packing density was 1.37 g/cm 3 .

(sprinkler device 14, seepage water catcher 18)

Sprinkling water is the use of a faucet to branch water. The sprinkling water is a sprinkling area of 4.7 m × 4.7 m in the center portion of the pretreatment tank 12, and four sprinklers 28 (sprinkling nozzles) are provided at four corners of the sprinkling area, and the sprinkler 28 is provided. The sprinkling radius is about 5 meters and the sprinkling range (angle) is 90 degrees.

The amount of water sprinkling is calculated by the number of sprinkling times per day (sprinkling interval) and the amount of sprinkling water per sprinkler. The sprinkling interval is performed by the timing control, and the opening operation of the electric valve 30 (solenoid valve) is started at the set time to start the water sprinkling; when the sprinkling amount of the flow rate cumulative value of the flow meter 32 reaches the set sprinkling amount after the sprinkling starts The closing operation of the electric valve 30 is performed to end the watering.

The oozing water is concentrated to the water collecting gauge 36 via the water collecting and venting grooves at the bottom of the pretreatment tank 12. As shown in Fig. 7, in order to maintain ventilation from the lower portion of the incineration ash, the water collecting gauge is regarded as a watertight structure. The oozing water is transferred to the oozing water storage tank by the bleed water pump 40.

(ventilation device 16)

The outside air is supplied from a blower 34 (air supply fan) provided outside the pretreatment tank 12 to a perforated pipe 24 constituting a water collecting and venting groove provided at the bottom of the pretreatment tank 12 to incinerate the ash layer. Ventilation.

The various operations of the sprinkling device 14, the effluent water collecting device 18, and the venting device 16 are controlled by the control device 20. The temperature-humidity sensor 42 is connected to the control device 20.

In an embodiment, the aeration is performed against the direction of water seepage through the sprinkling water in the incineration ash layer. At the time of the sprinkling treatment, by performing the aeration treatment, the water permeable rate of the sprinkled water passing through the incineration ash layer becomes smaller over time after the start of the sprinkling, as compared with the case where the aeration treatment is not performed.

That is, the amount of elution of heavy metals and organic matter in the incineration ash layer into the permeated water is greatly affected by the water seepage speed, but in the pretreatment of the sprinkling water, the temporal change of the water permeability speed becomes smaller as described above. Therefore, the amount of elution of the eluted material into the oozing water is less changed over time, thereby ensuring a stable dissolution state. As a result, the change in the speed of the water permeable rate over time is suppressed, and the time-dependent fluctuation of the elution amount is stabilized, and as a result, the highly reliable pre-treatment quality can be ensured.

Further, when the water is sprayed without using the aeration treatment, a channel which is easily permeable to water is formed in the incinerated ash layer, and the sprinkled water can flow along the passage. However, when the aeration treatment is performed from the lower side against the water seepage direction, water seepage can be uniformly performed in the incinerated ash layer, thereby suppressing the unevenness of the water seepage place.

This ventilation treatment is preferably carried out together with watering. Alternatively, watering and aeration treatment may be performed one after the other. In this case, the watering treatment may be performed first, or the ventilation treatment may be performed first, but the time interval between the two treatments must not be left. Preferably, the next processing is performed one after the other after the end of the previous processing.

(operating conditions of the pre-processing equipment)

(sprinkling conditions)

Sprinkling water 1.2 m ^ 3 / day

The amount of water oozing is 0.96 m ^ 3 / day

Exuded water volume / sprinkling volume 80%

The liquid-solid ratio of 0.6 after the date of the 50th

(ventilation conditions)

Vent line speed is approximately fixed at 1.8 mm/sec

(effect)

(1) Maintenance of incineration ash temperature

Figure 8 is a graph showing the time-dependent changes in the temperature of the incineration ash and the temperature of the outside air during the pretreatment process.

(maintenance of incineration ash temperature due to self-heating)

After maintaining the temperature higher than the outside air from the start of the pretreatment, it was found that the temperature of the incineration ash increased due to self-heating. This state is lowered after reaching the peak value 10 days after the start of the pre-processing, and is maintained at a state higher than the outside air temperature until the end of the pre-processing. The change in the temperature of the incineration ash at a depth of 0.3 m as shown in the conventional method shows a tendency to be substantially the same as the temperature of the outside air at an early stage even after the start in the summer. Increasing the landfill depth of incineration ash can achieve the effect of maintaining the temperature of the incineration ash.

(temperature change of the upper incineration ash)

From the time-dependent changes in the incineration ash temperature of the upper layer (0.4 m depth) and the middle layer (0.8 m depth), the upper layer has almost no temperature drop at a landfill depth of 0.3 m as shown by the conventional method. The temperature of the incineration ash in the upper layer is compared with the temperature of the incineration ash in the middle layer, and it is found that the temperature of the incineration ash in the upper layer tends to decrease at an earlier temperature. This is because by increasing the landfill depth of the incineration ash, the heat from the movement of the middle layer suppresses the decrease in the temperature of the incineration ash in the upper layer, but the depth of 0.4 m is affected by the outside air. Therefore, it is considered that it is desirable to have a landfill depth of 0.8 m or more for the temperature at which the incineration ash is maintained by at least the self-heating phenomenon.

(temperature change of the lower incineration ash)

From the time-dependent change of the incineration ash temperature of the lower layer (1.4 m in depth) and the upper layer (0.4 m in depth), it was found that the surface was sealed with urethane foam on the bottom surface 10 days after the start of the pretreatment. The lower incineration ash temperature is lower than the upper incineration ash temperature, which is considered to be due to the cooling effect caused by the supply of gas from the bottom surface. The tendency to rise is shown around the 10th day after the start of the pre-treatment, which is considered to be because the heat generated by the self-heating phenomenon is greater than the cooling caused by the supply gas. Then, around the 15th day after the start of the pretreatment, the temperature of the incineration ash in the lower layer and the temperature of the incineration ash in the upper layer are reversed; after 30 days, the temperature of the incineration ash in the lower layer and the temperature of the incineration ash in the middle layer (0.8 m in depth) are reversed. Turn, so it can be judged that the bottom insulation is effective for maintaining-managing the incineration ash temperature.

(pre-processing effect)

(Effect of giving EC value of exuded water)

Fig. 9 is a graph showing the temporal change of the EC value (conductivity) of the oozing water during the pretreatment process. The EC value was less than 1.2 Siemens/meter (S/m) around 30 days after the start of the pretreatment; on the 40th, the EC value was less than 1.0 Siemens/meter (S/m). This result is compared with the pretreatment conditions and landfill depth shown in the conventional method (known method: depth 0.3 m; example: depth 1.8 m), peak value of initial EC value (known method: about 3 Siemens / Metric (S/m); Example: about 4 Siemens/meter (S/m)), but showing the elapsed time of EC value (conductivity) of the oozing water shown during the summer season with the conventional method Since the EC value (conductivity) of the oozing water having the same change is changed with time, it is considered that the landfill depth and the pretreatment conditions shown in the examples can obtain the same effects as when the landfill depth is 0.3 metre.

(Effect of giving TOC concentration of exuded water)

Fig. 10 is a graph showing temporal changes in TOC (total organic carbon) concentration of water oozing during the pretreatment process. The TOC concentration was less than 500 mg/l around 30 days after the start of pretreatment; on the 40th, the TOC concentration was below 250 mg/l. As described above, this result is different from the pretreatment conditions and landfill depths shown in the conventional method (conventional method: depth 0.3 m; example: depth 1.8 m), peak value of initial TOC concentration (known method: About 800 mg/l; Example: about 2000 mg/l) is different, but shows the elapsed time of the TOC concentration of the exuded water which is substantially the same as the time-dependent change of the TOC concentration of the exuded water shown during the summer season of the conventional method. The change was confirmed to be about 1/10 of the peak value of the initial TOC concentration which can be lowered 50 days after the start of the pretreatment.

The judgment after the completion of the pre-processing may be performed by using a storage standard before storage based on the final treatment site or the like and a determination index considering the environmental influence caused by the oozing water. For example, when the dissolution value of the incineration ash is contained in the standard, the index indicating the concentration of the organic matter or the salt in the effluent water when the incineration ash satisfies the dissolution value of the storage standard may be used as an index for determination. However, in the case where the incineration ash meets the accommodation standard or the accommodation standard before the containment cannot be determined, the environmental impact due to the oozing water before the containment is taken into consideration, and the concentration indicating the concentration of the organic matter or the salt in the effluent water is used as an additional standard. The indicator can be used as an indicator of judgment. For example, it may be determined as an index indicating the total organic carbon concentration (TOC) in the effluent water, and the total organic carbon concentration (TOC) in the effluent water is used as an index. For example, when the TOC of the oozing water becomes 100 mg/l, it is judged that the pretreatment is completed. In order to achieve this criterion, although there is some fluctuation due to the influence of the nature of the incineration ash, it is confirmed by experiments that the pretreatment is completed in a period of approximately 40 days to 50 days. Of course, as an index indicating the concentration of other salts, an electrical conductance (EC) or the like can be used as an index for determination. An advantageous aspect of using the TOC as a judgment index is that the value of the indicator substance is directly expressed as compared with the case where the TOC is not used as an index. Incidentally, when other ECs or the like are used as the judgment index, for example, a value of 1.0 Siemens/meter (S/m) may be used as a reference.

According to the pretreatment described above, the TOC concentration, the EC value, and the like of the incineration ash can be reduced in a short period of time, and it is also advantageous in terms of reducing the amount of water used in the sprinkling treatment.

In particular, as shown in Fig. 8, in areas and seasons where the ambient gas temperature varies between 18 ° C and 28 ° C, since it is not necessary to heat the incineration ash from the bottom wall or the side wall, it will be generated from the incineration ash at the initial stage of the accumulation. The heat is maintained in the pretreatment tank, so that the temperature of the incineration ash can be maintained at a desired temperature range higher than the outside air temperature without using a heater, in an attempt to make the energy required for the pretreatment of the incineration ash. The low reduction is beneficial.

The pre-treated incineration ash thus completed in the pretreatment process is put into the storage structure of the final treatment site, and is landfilled in a predetermined manner, or reused as an aggregate, a soil filling material, a backfill material, or the like.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

10‧‧‧Pre-processing equipment

12‧‧‧Pre-treatment tank

14‧‧‧ sprinkler

16‧‧‧Ventilator

18‧‧‧Exuding water collection device

20‧‧‧Control device

22‧‧‧Insulation

24‧‧‧With a hole tube

26‧‧‧Incineration ash

28‧‧‧ sprinkler

30‧‧‧Electric valve

32‧‧‧ Flowmeter

34‧‧‧Air blower

36‧‧‧Water Collector

38‧‧‧temperature sensor

40‧‧‧Exudation pump

42‧‧‧Temperature-humidity sensor

Fig. 1 (A), Fig. 1 (B), and Fig. 1 (C) respectively show temporal changes in ambient gas (air temperature) and incineration ash temperature during the pretreatment test period during the summer season, the fall period, and the winter season.

Fig. 2 is a view showing an EC value (conductivity) of oozing water.

Fig. 3 is a graph showing the TOC (total organic carbon) concentration contained in the oozing water.

4(A), 4(B), 4(C), and 4(D) are graphs showing the results of concentration analysis of EC values and TOC, Ca, and Na, respectively.

Figure 5 is a front elevational view of the pre-processing device.

Figure 6 is a plan view of the pre-processing apparatus of the embodiment.

Fig. 7 is an explanatory view of a water collecting gauge used in the embodiment.

Fig. 8 is a graph showing changes with time of the incineration ash temperature and the outside air temperature during the pretreatment process of the embodiment.

Fig. 9 is a graph showing temporal changes in EC value (conductivity) of oozing water during the pretreatment process.

Fig. 10 is a graph showing temporal changes in TOC (total organic carbon) concentration of water oozing during the pretreatment process.

10. . . Pre-processing equipment

12. . . Pre-processing tank

14. . . Sprinkler

16. . . Ventilation device

18. . . Seepage water collecting device

20. . . Control device

twenty four. . . Perforated tube

26. . . Incineration ash

28. . . Sprinklers

30. . . Electric valve

32. . . Flow meter

34. . . Blower

36. . . Water collecting device

38. . . Temperature sensor

40. . . Seepage pump

42. . . Temperature-humidity sensor

Claims (11)

A pretreatment method for incinerating ash, which is stored in a pretreatment tank before the incineration ash is buried or used as an aggregate, a fill material, a backfill material, etc., and the incinerated ash is The pretreatment process of the water sprinkling treatment and the aeration treatment is characterized in that the bottom treatment wall including at least the partition wall and the side wall rising from the bottom wall and the temperature sensor are provided in the front treatment tank. Between at least 10 days from the pre-treatment, the incineration ash is ventilated through the hole, and the temperature inside the incineration ash is monitored by the temperature sensor to maintain the temperature of the incineration ash at 20 ° C or higher. Below 60 °C. The method for pre-treatment of incineration ash according to claim 1, wherein a height of the incineration ash from a bottom surface of the pretreatment tank is 0.8 m or more, so that the incineration ash is generated from the incineration ash at the initial stage of deposition. The heat is maintained in the above pretreatment tank. The method for pre-treatment of incineration ash according to claim 1, wherein the stacked incinerated ash is covered with a mat having heat insulation and water permeability to suppress a decrease in temperature of the incinerated ash. The pretreatment method for incineration ash according to claim 1, wherein a heat insulating material is provided on the bottom wall or the side wall to suppress a temperature decrease of the incineration ash. The pretreatment method of the incineration ash according to any one of the preceding claims, wherein the sprinkling treatment is performed by sprinkling water from above the pretreatment tank; The ventilation process performs air flow upward from the hole of the bottom wall. A pretreatment method for incinerating ash, which pre-treatments the sprinkling ash and aeration treatment before re-using the incinerated ash or before reusing it as an aggregate, a fill material, a backfill material, or the like The utility model is characterized in that at least a bottom wall including a spacing hole and a side wall rising from the bottom wall, a temperature sensor, a heater, and the front device for controlling the temperature sensor and the heater are provided In the treatment tank, the incineration ash is subjected to aeration treatment through the hole, and the temperature inside the incineration ash is monitored by the temperature sensor at least 10 days from the pretreatment, and the heater is used to The incineration ash is heated to maintain the temperature of the incinerated ash at 20 ° C or higher and 60 ° C or lower. The method for pre-treatment of incineration ash according to claim 6, wherein a height of the incineration ash from a bottom surface of the pretreatment tank is 0.8 m or more, so that the incineration ash is generated from the incineration ash at the initial stage of deposition. The heat is maintained in the above pretreatment tank. The method for pre-treatment of incineration ash according to claim 6, wherein the stacked incinerated ash is covered with a mat having heat insulation and water permeability to suppress a decrease in temperature of the incinerated ash. The pretreatment method for incineration ash according to claim 6, wherein the bottom wall or the side wall is provided with a heat insulating material to suppress a temperature drop of the incineration ash. The pretreatment method of the incineration ash according to any one of the items of the present invention, wherein the sprinkling treatment is performed by spraying water from above the pretreatment tank; and the aeration treatment is performed from the above The above holes of the bottom wall circulate air upward. The method for pre-treatment of incineration ash according to any one of claims 6 to 9, wherein the incineration ash is heated from the bottom wall or the side wall to suppress a decrease in temperature of the incineration ash.