KR101272788B1 - Treating method of hydrous waste - Google Patents

Abstract

It is an object of the present invention to provide a method for treating pollutant-containing water and other water-containing waste, which can be carried out more easily than before. According to the present invention, the moisture reduction step of contacting the quicklime (2) to the water-containing waste (1), and by heating above the decomposition temperature of the calcined lime (3) generated by the quicklime (2) absorption reaction reaction quicklime (2) In the regeneration step, the slaked lime 3 and the granular heating medium 4 were heated. In the regeneration step, the granular heating medium may be blown with air.

Description

TREATING METHOD OF HYDROUS WASTE}

The present invention relates to a method for treating water-containing waste.

Conventionally, aromatic compounds, organic chlorine compounds, pesticides, dioxins, etc. contained in waste liquids, such as developing wastes, wastewater treatment of incinerators, wastewater from workplaces, landfill leachate drainage, and landfill wash water. There has been an application for the electrochemical oxidative decomposition of hardly decomposable substances such as nitrate ions such as, PCB, and water-soluble polymers (Patent Document 1).

This application considers that it is difficult to sufficiently treat the hardly decomposable compounds in the waste liquid or the waste liquid, including the leachate drainage from the landfill after waste treatment, the developing waste liquid, the chemical plant drainage, and the conventionally widely used biotreatment and flocculation methods. It is an object of the present invention to provide a method of electrochemically oxidatively decomposing waste liquids, such as developing wastes, by electrolysis at a high current density. By electrolysis at a density, hypohalogenic acid or active oxygen is generated in the waste liquid or drainage to give a strong oxidative decomposition effect. It is able to oxidatively decompose hardly decomposable compounds .

However, such treatment of wastewater (reducing pollutant components) by electrolysis has a problem that is hard to control.

Japanese Patent Laid-Open No. 2003-126860

It is therefore an object of the present invention to provide a method for treating pollutant-containing water and other water-containing waste, which can be carried out more easily than before.

In order to solve the above problems, the present invention takes the following technical means.

(1) The method for treating water-containing waste of the present invention includes a water-reducing step of contacting quicklime with water-containing waste, and a regeneration step of regenerating quicklime by heating above the decomposition temperature of slaked lime produced by the quicklime absorption reaction. In the regeneration step, the hydrated lime and the granular heating medium are heated.

Here, as the water-containing waste (the case where the "solid" is the main subject or the case where the "moisture" is the main subject, etc.), the water containing contaminants, such as wastewater of a factory, such as a chemical plant or a liquid crystal manufacturing plant, a factory or a gas station demolition site Contaminated soil by heavy oil, kerosene, etc., its effluent, plumed seasoning waste (has high COD and high salt concentration), manure of pigs and chickens, manure of other livestock, household food waste, fast food restaurants Examples include ketchup and other residues of restaurants, contaminated blood in hospitals, wastes of fish and shellfish, livestock and other carcasses.

Examples of contaminants in the contaminant-containing water include oils such as solvents and other organic compounds (for example, DMSO, DMAc, DMF, MEA), A heavy oil, and light oil. In addition, COD, TOC, n-nucleic acid extract, ammonia nitrogen, nitrate nitrogen, etc. may be exemplified as indicators of the contaminant.

The water reduction step and the regeneration step may be performed continuously, may be independent of each other over time, or may be performed in parallel as a loop (cyclic ring) cycle.

Since the water-based waste treatment method has a water-reducing step of contacting the quicklime with the fastener, the quicklime reacts with the calcined circuit by chemical absorption, causing spontaneous heating to generate <CaO + H ₂ O → Ca (OH) ₂ + 63ｋJ / mol. >, In this process, the moisture content of the absorption reaction component of quicklime is reduced from the water-containing waste.

In addition, the water-containing waste is also reduced by evaporation of moisture other than the absorption reaction component of quicklime. Specifically, in the water reduction process, quicklime is hydrated and chemically changed in the calcination cycle. The heat of hydration reduces the moisture of the water-containing waste by evaporation. That is, the spontaneous exothermic reaction when the quicklime changes to the hydrated lime can be used to evaporate the water of the waste water, thereby reducing the amount of heat required in the regeneration process.

In the water-reducing process, it is desirable to set the amount of the mixed waste water and quicklime so as to reduce the amount of water in the water-containing waste, until the water is almost gone. As a result of the use of quicklime for the treatment of water-containing wastes, the water-based wastes are not treated in water (liquid) but in a dry state (smeared lime even after maintenance) to facilitate handling in the next process. Can be.

In addition, since the quicklime has a regeneration step of regenerating quicklime by heating it to a decomposition temperature (580 ° C) or higher generated by absorption of the quicklime, the slaked lime is heated in an aerobic atmosphere at, for example, about 580 to 1000 ° C. As it is decomposed and combined with oxygen, it is regenerated into quicklime, and contaminants (COD, TOC, n-nucleic acid extract, ammonia nitrogen, and nitrogen nitrate) of hydrous waste are thermally decomposed and reduced. Organics are almost completely pyrolyzed when heated above 650 ° C (environmental loads decompose). As a result, it can contribute to environmental conservation through zero-immission that does not emit water-based waste, which is a load on nature.

In this way, the hydration heat of quicklime in the moisture reduction process or the heating in the regeneration process is thermally decomposed, so that the heat of hydration of quicklime in the moisture reduction process is used for pyrolysis of the pollutant or in the regeneration of quicklime in the regeneration process. The amount of heat to be heated can be used for pyrolysis of the contaminant, so that the contaminant can be decomposed by a relatively simple method compared to a treatment in which the control by the electrolysis method is complicated.

In addition, in the regeneration step, the slaked lime and the granular heating medium are heated, so that the thermal conductivity of the slaked lime is improved by the granular heating medium to increase the treatment efficiency (shortening of the treatment time and reduction of required heat amount).

Furthermore, quicklime → slaked lime (moisture reduction step), ⇒ slaked lime → quicklime (regeneration step), ⇒ quicklime → slaked lime (moisture reduction step), ⇒ slaked lime → quicklime (regeneration step),. It is possible to regenerate and reuse quicklime repeatedly (different from simply throwing away the absorbed lime on acidic soil as it is), and such a recycling can suppress drug running and coasting.

In addition, it is also possible to treat the high concentration of water-containing waste (for example, organic wastewater having a COD of 1000 ppm or more) that is difficult to treat due to the insufficient amount of oxidant by the electrolysis method. The treatment principle of the electrolysis method is an oxidizing agent, whereas the treatment principle of the present invention is a pyrolysis method.

Combining the electrolytic action as described below here results in a considerably desirable advantage in the actual treatment capable of suppressing odors.

(2) In the regeneration step, the granular heating medium may be blown with air.

In this manner, when the granular heating medium (in the heating and regeneration furnace in which the heater is wound around the periphery) is blown, for example, from below, the granular heating medium behaves as if it is a fluid flow chamber. In the media (doctor) bath, the slaked lime is electrothermally heated from the surrounding heating medium to chemically change into quicklime. That is, slaked lime can be made excellent in heat transfer efficiency by the contact heating with the granular heating medium bath of all around.

In addition, when the water-containing waste contains a volatile organic component, the organic component is inhibited from moving upward by the obstacle action of the granular heating medium bath layer, and is thermally decomposed while staying in the layer. The components may be less likely to leak to the outside. That is, by controlling the layer thickness of the granular heating medium bath, it is possible to appropriately increase the leakage preventing function of the VOC gas component.

(3) The granular heating medium may have a smaller specific heat than air.

An alumina powder can be illustrated as said granular heating medium. This alumina (specific heat: 0.19 cal / g · ° C) has a specific heat smaller than that of air (specific heat: 0.24 cal / g · ° C), and tends to be warmer than air and easily transferred. Therefore, in the regeneration step of regenerating quicklime by heating above the decomposition temperature of slaked lime (for example, about 580 to 1000 ° C), the alumina powder can quickly absorb the ambient temperature and quickly conduct heat conduction to the slaked lime. And the specific heat of slaked lime is 0.28 cal / g * degreeC.

In this way, the thermal conduction efficiency of the slaked circuit can be excellent in the regeneration step, and can be excellent in energy saving and cost reduction.

(4) The granular heating medium may have a specific gravity greater than that of quicklime.

Alumina powder (specific gravity: 3.97) can be illustrated as said granular heating medium. The volumetric weight of quicklime is about 1 and the volumetric weight of calcined lime is about 0.5 with respect to the specific gravity of 3.97.

In this configuration, in the regeneration process of regenerating quicklime by heating above the decomposition temperature of hydrated lime (for example, about 580 to 1000 ° C), the quicklime is higher than the alumina powder due to the difference in the specific gravity of the quicklime and the alumina powder. Alumina powder (which is harder to fly than calcareous lime) is more likely to fly due to greater gravity due to the transfer of quicklime lime into other flow paths. It is possible to separate from. The separated quicklime is then sent back to the moisture reduction process to contact with the wastewater.

(5) The hydrous waste may be electrolyzed.

In this way, even if the water containing the waste water and pollutants contains odorous or malodorous components, it is possible to decompose and reduce the bad odor components by the oxidizing power of hypochlorous acid and OH radicals generated by the electrolysis. Can be erased.

Specifically, when electrolytic water is added to the water waste or electrolysis of the water waste itself, contaminants are subdivided by the oxidizing power of hypochlorous acid or OH radicals, and bad odors are decomposed, thereby suppressing the occurrence of strange odors. To prevent.

(6) When the alumina powder is blown in the regeneration step, the salt is separated from the flow chamber of the alumina powder.

That is, alumina has a melting point of 2054 ° C and a boiling point of 3000 ° C, whereas sodium chloride has a melting point of 801 ° C and a boiling point of 1514 ° C. Therefore, alumina powder is a solid (grain) in the temperature range of 801 to 1000 ° C. It is a molten liquid state, and the salt in the liquid phase can be separated as it flows downward, so that the salt in the water-containing waste can be desalted. The desalted salt can be reused (to give conductivity to the water to be treated) at the time of electrolysis or the like.

(7) In the regeneration step, when the alumina powder is blown with air, metals are separated from the flow chamber of the alumina powder.

In other words, the specific gravity of iron oxide is around 5 and the manganese oxide is 4.5, which is larger than that of 3.97 of alumina. Therefore, the regeneration step moves downward due to the difference in weight in the flow chamber of the alumina powder. In addition, the specific gravity of sodium chloride is 2.17, which is smaller than that of alumina. However, in the temperature range of 801 to 1000 ° C., the salt flows downward in the alumina powder since the salt is in a molten liquid state.

(8) It may have a microwave heating process for evaporating the moisture of the slaked lime produced | generated in the said water reduction process, and may move to a regeneration process after that.

The microwave heating is a principle of the microwave oven, and water can be evaporated by being irradiated with microwaves at 2.45 GHz, for example, microwave drying (microwave drying). Thereby, cost can be reduced by reducing heating energy in a regeneration process.

(9) The water-soluble waste may be brought into contact with the absorbent carrier.

Examples of the absorbent carrier include activated carbon (having adsorption), bentonite (having absorbency), and plant fiber debris (having absorbency with wood chips, sawdust, etc.). It can adsorb | suck and absorb a component and moisture. In addition, the quicklime circuit can act as an evaporation function of the initial moisture by the action of generating heat of hydration, and have an absorption function of a contaminant in the absorption carrier.

The bentonite or plant fiber debris absorbed here is restored to its original dry state when heated to a temperature range of 580 to 1000 캜 in the regeneration process.

(10) The water of the water-containing waste may be separated during or after the water reduction step, and the inorganic material dissolved in the water may be reused. As said inorganic substance, salt can be illustrated, for example.

With this configuration, the water-containing waste, for example, pollutant-containing water, for example, plum seasoned waste liquid, has a high COD (for example, 100,000 to 200,000 ppm or more) and a high salt concentration (for example, 1 to 1). 20% or more), but the inorganic components dissolved in the water can be separated by separating the slaked lime, the solid content and the water into a membrane, for example, and the salt contained in the plum seasoning waste liquid can be extracted as a high concentration water. By electrolyzing this high concentration saline solution, for example, functional water containing hypochlorous acid (available as the electrolytic water or other water treatment) can be obtained.

(11) This invention has the following other features.

1) dry treatment

In the present invention, the moisture is reduced by quickliming the water-containing waste in the water-reducing process, so that the water-containing waste can be dried rather than wet, so handling is easy and the water-soluble waste is reduced.容 化), and bad smell is not generated easily.

In the moisture reduction process, the mixing ratio of the water-containing waste and quicklime may be adjusted to become anhydrous to near anhydrous.

2) Mixing ratio of quicklime and water waste

When the moisture in the quicklime and the water-containing waste is adjusted to a ratio of 1: 1 in molar ratio, all of the calcium oxide (quick lime) and water (water in the water-containing waste) are chemically converted into calcium hydroxide (calcined lime). Moisture evaporates by generating a large heat of reaction (heat of hydration), so it is preferable to set the ratio of water more than 1: 1 in molar ratio. In other words, it is possible to treat a water-containing waste containing at least 1: 1 water in a molar ratio by quicklime.

It is preferable to adjust the compounding ratio of the quicklime and the water-containing waste in anticipation of the calorific value at the time of the chemical reaction (= treatment at the water reduction step). For example, if the amount of water-containing waste to quicklime is adjusted to approximately 100 ° C. in the moisture reduction process, the amount (necessary amount) of quicklime in terms of heat generation and reduction of moisture can be excellent in terms of cost balance. have.

3) Treatment of pollutant component of high concentration drainage

When water-based waste (when "water" is mainly) contains a large amount of contaminants (e.g., seasoning liquids or solvents in the food industry), for example, COD drainage of more than 100,000 to 200,000 ppm Seasoning wastes, etc.) are extremely difficult to treat at high concentrations by electrolytic treatment (the COD is not sufficiently lowered). However, in the present invention, hydration of quicklime (absorbs moisture) in the moisture reduction process and The heat of hydration (moistures the water) is used to reduce the moisture and to be fired in the regeneration process (heating above the decomposition temperature of the slaked lime to change the properties of the substance). It is relatively easy to use, but does not require subtle electrical control (current value control, voltage value control, flow rate control of the treated water or pH control) as in the case of electrolysis. The COD components are all oxidatively decomposed because they are exposed to high temperatures (eg 700 ° C or higher) above the decomposition temperature of the slaked lime (melting point 580 ° C) in the regeneration process. It is almost completely oxidized to carbon dioxide and water.

Thus, it is unconventionally considered that the COD component is almost completely treated even at high concentrations of drainage, and when combined with liquefaction and regeneration of water evaporated in the water reduction process, the high concentration of wastewater can be converted into high clean water. In other words, COD and other pollution evaluation indicators can be regenerated by treating a wide range of objects from high concentration drainage, wastewater, and drainage to low concentration drainage.

4) Noodles, noodles, etc.

Noodles such as udon noodles, noodles, etc. The remaining water after drinking or drinking broth contains starch powder (organic matter), which has a high COD value, and the environmental burden caused by restaurants discharging the discarded broth into rivers or sewage is problematic. When the waste broth containing the udon chops is treated as a water-containing waste, it is dehydrated after the water reduction process, and the slaked lime and starch are mixed. This eliminates the need for discharge and reduces the environmental load.

5) Disposal of leftovers such as shochu and salt-containing alcoholic beverages

Sewage residues left in large quantities during the production of soju are used for landfilling, and the sluggish properties may cause ground fluidization problems. In addition, waste alcohol beverages or returned alcoholic beverages that have been discontinued are subject to tax refunds when a large amount of salt is added so that they cannot be consumed.

Therefore, when the residue or saline-added alcoholic beverage after the soju is treated as a water-containing waste is dehydrated and de-alcoholic after the water reduction step, calcined lime and fiber or salt are mixed, and this is, for example, in a regeneration process. By firing at 700 ° C or higher, there is no need for landfilling or stream discharge, and the environmental load can be reduced.

6) Disposal of waste such as mayonnaise and ketchup

In fast food restaurants and restaurants, a large amount of waste such as mayonnaise, ketchup, ice cream, soft cream, and dressing is produced. When these are treated as water-based wastes, they are dehydrated after the water-reducing process and mixed with lime and oil. When firing at a process, for example, 700 ° C. or higher, the fat or oil component is burned, and this residual heat can be used as a fuel by using waste heat.

7) Treatment of circulating water of scrubber

Algae grow in the scrubber's circulating water, and odor is generated over time. However, when this waste circulating water is treated as a water-containing waste, it is dehydrated after the water-reducing process, and mixed with hydrated lime and plant fiber. For example, the water evaporated in the moisture reduction step is collected and liquefied, and reused by firing it in the regeneration step at, for example, 700 ° C or higher.

8) Processing when `` solid content '' is the principal

In the tofu manufacturing process, the remaining residues of soy milk from soybeans are rich in plant fiber, calcium, protein, carbohydrates and potassium, but they are mostly disposed of as industrial waste because of their rapid deterioration in quality and difficulty in long-term storage. It is a reality. When this waste paper is treated as a water-containing waste, it is dehydrated after mixing in water and mixed with hydrated lime. For example, when it is fired at a regeneration process at 700 ° C or higher, the fiber component burns and the residual heat is used as waste heat. It can function as a fuel. In addition, this eliminates the need to dispose as industrial waste, thereby contributing to environmental conservation by zero-immission.

9) Treatment of Paint Balance

When wastewater containing a large amount of solids, such as paint residues, is treated as a water-containing waste, it is dehydrated after the water-reducing process, resulting in a mixture of slaked lime and organic components. The lower surface can be used as a supporting agent as the organic components and the like burn.

10) Treatment of livestock manure and animal manure

If the water-containing waste is originally low in water content (such as pig dung, chicken dung, cow dung, or animal dung in zoos, etc.) (when `` solids '' are the main substance), it is further dried by absorbing or evaporating in the water reduction process. The manure can be made in one state (which hardly produces a bad smell), and the manure is then heated by heating it to a high temperature (eg 700 ° C or more) above the decomposition temperature (melting point of 580 ° C) in the regeneration process. The calcined lime can be recycled to quicklime while making it close to ashes.

11) Suppression of propagation of fungi and viruses

In the present invention, the water-containing waste can be dehydrated in the water reduction step, so that propagation of various fungi and the like in the waste can be suppressed and deodorized and disinfected.

12) Animal carcass processing

When water is added to carcasses and cut into a mixer and treated as a water-containing waste, it is dehydrated after the water reduction step and mixed with slaked lime and calcined at, for example, 700 ° C or higher in the regeneration step. In the water reduction process, the hydrous waste can be dehydrated, so that propagation of decaying fungi in the waste can be suppressed, and the waste can be treated without being troublesome.

13) Reuse of reduced moisture

In the process of reducing water (as described above), the evaporated water can be collected, cooled, and liquefied for reuse. In particular, when the throughput is large, such as plant drainage, it is preferable to liquefy and reuse as industrial water without releasing it to the atmosphere.

Specifically, when the plant drainage (including organic solvents such as DMSO) of the liquid crystal manufacturing plant was treated in a water reduction step, and the water quality of the collected and liquefied water was analyzed here, the cleanliness was as high as that of distilled water. By further treating this water with a reverse osmosis membrane, it can be reused as ultrapure water.

14) Contamination Components of Organics in Regeneration Process

In the regeneration process, when heating to a high temperature (eg 700 ° C or higher) above the decomposition temperature (melting point 580 ° C) of the slaked lime to recover the limestone, the calcined calories or organic components derived from the pollutant adhered to the container are oxidized The contaminants are almost completely oxidatively decomposed, while saving heating energy as they are released. Here, other heat may be heated by using heat generated in the water reduction process or heat generated in the regeneration process.

15) Treatment of contaminated soil and separation of quicklime

Electrolyzed water is applied to contaminated soil such as oil, and the contaminated components are subdivided or decomposed by the action of hypochlorous acid or OH radicals, and the polluted soil (water-containing waste) is sent to the water reduction process, and then regenerated. With respect to the final product after treatment at, for example, 700 ° C. or higher, the quicklime and the soil components of the soil can be separated as follows.

That is, since the volume specific gravity of the soil is 1.8 and the volume specific gravity of the quicklime is 1.06, the wind is made by using the difference of the specific gravity to separate the soil and the quicklime by using the difference between the two fluidities. The soil is then backfilled with soil and the quicklime is reused for the next treatment. And even if quicklime is mixed in the soil can be utilized as a soil improver.

16) Separation of slaked lime and inorganic components after water reduction process

After the water reduction process, the inorganic components in the slaked lime and contaminants can be separated as follows. That is, by using the difference in specific gravity (apparent specific gravity 0.40 to 0.55) and other inorganic components, for example, the density of salt (2.16 g / cm 3), the fine powder is applied to the wind and the difference in fluidity between the two These can be separated, and the salt separated from the slaked lime can be reused for electrolysis or the like.

17) Firing of shells

If the water-containing waste contains calcium carbonate, such as shells (oysters, clams, clams, etc.), the chemical change of calcium carbonate (melting point 825 ° C) to calcium oxide (= quicklime) when heated above 900 ° C in the regeneration process Because of this, quicklime can be increased in the original amount. It is also possible to intentionally mix and treat a substance containing calcium carbonate, such as a clam shell, with water-containing waste.

18) Disposal of infectious waste such as contaminated blood or disposable medical devices in hospitals

Such water-containing waste can also be properly disposed of by dehydration of quicklime.

The present invention is configured as described above has the following effects.

Contaminant components can be separated by a relatively simple method compared to the treatment by the electrolytic method, thereby providing a method for treating water-containing waste which can be carried out more easily than conventionally.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an apparatus flow diagram illustrating an embodiment of a method for treating wastewater of the present invention.

Hereinafter, embodiments of the present invention will be described.

As shown in Fig. 1, the method for treating water-containing waste of this embodiment includes a water reduction step of bringing the quicklime 2 into contact with the water-containing waste 1 (waste liquid), and the quicklime 2 generated by the absorption reaction. A regeneration step of regenerating the quicklime 2 by heating above the decomposition temperature of the slaked lime 3 is carried out so that the slaked lime 3 and the granular heating medium 4 are heated.

That is, the waste liquid which is the wastewater 1 which flowed into the waste liquid storage tank 5 is supplied to the screw 6 (rotated and driven by the motor M) by the pump P, and the quicklime 2 is carried out in the middle of the said screw. ) Is transferred to the heating regeneration furnace 7 (water reduction step), and introduced into the heating regeneration furnace 7. In the heating regeneration furnace 7, the slaked lime 3 is heated to be regenerated into the quicklime 2 (regeneration step), and the regenerated quicklime 2 is further flowed upward by air supplied by the compressor 8. 9) is transferred to the hopper 10 of the quicklime (2). In addition, water vapor and air in the heating and regeneration furnace 7 are discharged to the outside from the exhaust port 11.

A heater 12 is wound around the outer circumference of the heating regeneration furnace 7, and a water cooling jacket 15 through which the coolant 14 circulates through the heat insulating material 13 is externally installed. A valve V is provided below the regeneration furnace 7 to discharge the iron oxides and other metals or salts separated by the treatment into the receiving container 16 for disposal.

The water-containing waste (1) (waste liquid) causes electrolytic action by adding electrolyzed water (not shown), and the pollutant is subdivided by the oxidizing power of hypochlorous acid or · OH radical, and the odor component is decomposed. Odor generation can be suppressed or prevented.

In other words, even if the water containing the waste water or pollutant contains odor (weird smell) or odor-causing components, it is possible to reduce the odor component by decomposing the odor component by the oxidation power of hypochlorous acid or OH radical generated due to the electrolytic action. Can be erased.

Here, the water containing contaminants, such as waste water of a chemical plant or a liquid crystal manufacturing plant, may be used as the water-containing waste (the "solid" or the "water" is the main subject). Oil contaminated soil by heavy oil, kerosene, its effluent, plum seasoning waste (with high COD and high salt concentration), pig shit, chicken shit or other livestock shit, household food waste, fast food restaurants and other restaurants Residue and the like can be exemplified.

Examples of the contaminant in the contaminant-containing water include oils such as solvents and other organic compounds (for example, DMSO, DMAc, DMF, MEA), A heavy oil and light oil. In addition, COD, TOC, n-nucleic acid extract, ammonia nitrogen, nitrogen nitrate and the like can be exemplified as indicators of the contaminant.

The water reduction process and the regeneration process are performed in parallel as a loop (ring) cycle.

Next, the use state of the wastewater processing method of this embodiment is demonstrated.

Since the water-based waste treatment method has a water-reducing step of contacting the quicklime 2 with the wetted waste 1, the quicklime 2 absorbs and reacts chemically with the slaked lime 3 to spontaneously generate heat and is less than <CaO + H. ₂ O → Ca (OH) ₂ +63 kJ / mol> In this process, the moisture content of the absorption reaction component of quicklime 2 is reduced from the water-containing waste.

In addition, the water-containing waste 1 is also reduced by evaporation of moisture other than the absorption reaction component of the quicklime 2 by the heat generation. Specifically, in the water reduction step, the quicklime 2 hydrates and chemically changes to the slaked lime 3, and the heat of hydration generates heat and reduces the moisture of the water-containing waste 1. That is, the spontaneous exothermic reaction when the quicklime 2 hydrates and changes to the slaked lime 3 can be used for evaporation of water in the wastewater 1, and the amount of heat required in the regeneration process can be reduced.

Since the quicklime (2) is used for the treatment of the water-containing waste (1) in this way, the water-containing waste (1) is soft, even if the water is dried (repaired) instead of water treatment (liquid) (3). ) To make it easier to handle in the next process. In this way, it is preferable to set the mixing amount of the water-containing waste 1 and the quicklime 2 so as to reduce the water of the water-containing waste 1 until it almost disappears, in terms of handling and thermal efficiency in the next step.

In addition, since the quicklime 2 has a regeneration step of regenerating the quicklime 2 by heating above the decomposition temperature (580 ° C) of the slaked lime 3 generated by the absorption reaction, for example, 580 to 1000 in the step. When heated in an aerobic atmosphere at about ℃, the hydrated lime (3) decomposes and combines with oxygen to be regenerated into quicklime (2), thereby contaminating components (COD component, TOC component, n-nucleic acid extract material, and ammonia nitrogen) of the aqueous waste (1). , Nitrogen nitrogen and the like) are reduced by thermal decomposition. In particular, organic materials are almost completely pyrolyzed when heated above 650 ° C (environmental loads are decomposed). As a result, it is possible to contribute to environmental preservation through zero-immission that does not discharge the water-containing waste 1, which is a load on nature.

In this way, the heat of hydration of the quicklime 2 in the moisture reduction step or the heat of the regeneration step is pyrolyzed to contaminate the contaminant component, so that the heat of hydration of the quicklime 2 in the moisture reduction step is used as pyrolysis of the contaminant or regeneration. The amount of heat to be heated during regeneration of the quicklime 2 in the process can be used as pyrolysis of contaminants, and the contaminants can be decomposed by a relatively simple method compared to the treatment with complicated control by the electrolysis method. Has the advantage.

In the regeneration process, the slaked lime 3 and the granular heating medium 4 are heated so that the thermal conductivity of the slaked lime 3 can be improved by the granular heating medium 4 to increase the treatment efficiency. Shortening of processing time, reduction of required calories).

In addition, quicklime (2) → slaked lime (3) (water reduction process), ⇒ slaked lime (3) → quicklime (2) (regeneration process), ⇒ quicklime (2) → slaked lime (3) (moisture reduction step), ⇒ slaked lime (3) → quicklime (2) (regeneration process). In addition, the quicklime (2) can be repeatedly recycled and reused (different from simply discharging the absorbed lime into the acidic soil as it is), and the drug running and cost can be suppressed by such recycling.

The electrolytic method can also be suitably treated with high concentration of the water-containing waste 1 (for example, organic wastewater having a COD of 1000 ppm or more), which is difficult to treat due to insufficient amount of oxidant. The treatment principle of the electrolysis method is the oxidizing agent method. The treatment principle of the present invention is the pyrolysis method.

(2) In the regeneration step, the granular heating medium 4 is blown as described above. That is, the granular heating medium 4 in the heating regeneration furnace 7 provided with the heater 12 wound around the air is blown into the compressor 8 from below, and the granular heating medium 4 is like a fluid flow. It acts as it is, and the slaked lime 3 is electrothermally heated from the surrounding heating medium 4 in the granular heating medium 4 (doctor) bath, and chemically changes to the raw lime 2. That is, the slaked lime 3 can be made excellent in heat transfer efficiency by the contact heating with the granular heating medium 4 bath of a circumference | surroundings.

In addition, when the water-containing waste 1 contains a volatile organic component, the organic component is inhibited from moving upward by the obstacle action of the granular heating medium bath layer, and remains in the layer. During the pyrolysis, the VOC gas component may be less likely to leak to the outside. That is, by controlling the layer thickness of the granular heating medium bath, the leakage preventing function of the VOC gas component can be increased very appropriately.

(3) The granular heating medium 4 is smaller in specific heat than air. An alumina powder was used as the granular heating medium 4. This alumina (specific heat: 0.19 cal / g · ° C) has a specific heat smaller than that of air (specific heat: 0.24 cal / g · ° C), tends to be warmer than air, and is easily heat-transferred. Therefore, in the regeneration process of regenerating the quicklime 2 by heating it above the decomposition temperature of the slaked lime 3 (for example, about 580 to 1000 ° C.), the alumina powder quickly absorbs the ambient temperature and rapidly replaces the slaked lime 3. Can be thermally conductive. Moreover, the specific heat of slaked lime 3 is 0.28 cal / g * degreeC.

Therefore, it can be said that the heat conduction efficiency to the slaked lime 3 is excellent in a regeneration process, and it is excellent in energy saving and cost saving.

(4) The granular heating medium 4 has a larger specific gravity than the quicklime 2.

Alumina powder (specific gravity: 3.97) was used as the granular heating medium 4. With respect to the specific gravity of 3.97, the volume specific gravity of the raw lime (2) is about 1, and the volume specific gravity of the slaked lime is about 0.5.

Therefore, in the regeneration step of regenerating the quicklime 2 by heating it above the decomposition temperature of the slaked lime 3 (for example, about 580 to 1000 ° C), the quicklime is caused by the difference in the specific gravity of the quicklime 2 and the alumina powder. (2) becomes easier to fly upward than the alumina powder (the slaked lime (3) is heated in the process of soaring and changes to the quicklime (2)), by transferring the quicklime quicklime (2) to another flow path It becomes possible to separate from the alumina powder (which is harder to fly than the slaked lime 3) larger and more susceptible to the action of gravity. Then, the separated quicklime (2) is sent to the moisture reduction process again to contact with the water-containing waste (1).

(5) In the regeneration process, the alumina powder is blown as described above, and the salt is separated from the flow chamber of the alumina powder.

That is, alumina has a melting point of 2054 ° C and a boiling point of 3000 ° C, whereas sodium chloride has a melting point of 801 ° C and a boiling point of 1514 ° C. Therefore, alumina and powder are solids (solids) in the temperature range of 801-1000 ° C. It is in a liquid state, and the salt in the liquid phase can be separated as it flows downward, and desalination of the salt in the water-containing waste (1) is possible. The desalted salt can be reused (to give conductivity to the water to be treated) at the time of electrolysis or the like.

(6) In the regeneration process, the alumina powder is blown as described above, and metals are separated from the flow chamber of the alumina powder.

That is, since the specific gravity of iron oxide is around 5 and manganese oxide is 4.5, and both are larger than 3.97 of alumina, in a regeneration process, it moves downward by the weight difference in the flow chamber of an alumina powder. In addition, sodium chloride has a specific gravity of 2.17, which is smaller than that of alumina, but in the temperature range of 801 to 1000 ° C., the salt is in a molten liquid state, so that the flow of alumina and powder flows downward.

Contaminants can be decomposed by a relatively simple method compared to a complicated treatment such as an electrolysis method, and can be easily carried out than before, and can be applied to the use of various water-containing waste treatment methods.

One; Water waste
2; quicklime
3; Slaked lime (compared with smaller granules)
4; Heating medium (shown in comparatively large granules)

Claims (5)

A water-reducing step of contacting quicklime with water-based waste, and a regeneration step of regenerating quicklime by heating above the decomposition temperature of slaked-lime produced by absorption reaction of the quicklime, wherein the regeneration step is carried out. The method for treating water-containing waste, characterized in that the calcined lime and alumina powder to be heated together.
The method of treating water-containing waste according to claim 1, wherein the alumina powder is blown in the regeneration step.
delete delete The method of claim 1, wherein the hydrous waste is electrolyzed.

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