JP5810110B2 - Waste liquid treatment system and waste liquid treatment method - Google Patents

Description

  The present invention relates to a waste liquid treatment system and a waste liquid treatment method.

  Conventionally, a method using a spray drying device (spray dryer) is widely known as a method for treating a waste solution such as plating waste solution. However, since the exhaust gas of the spray drying device contains dust, the treatment of the exhaust gas is not possible. It becomes a problem.

  Patent Document 1 below discloses a processing system in which a dust processing device (scrubber) and a spray drying device are combined. In this treatment system, the exhaust gas is treated using the waste liquid as the scrubber treatment liquid, so that the waste liquid and dust can be treated without leaking to the outside, and active ingredients that can be collected and recycled are collected. It can be recovered.

JP 2002-346545 A

  However, since the waste liquid is directly introduced into the scrubber in the above treatment system, there is a problem that the waste liquid having corrosive properties such as strong acid and strong alkali cannot be treated. In addition, the amount of waste liquid that can be sprayed and circulated in the scrubber is limited by the capacity of the scrubber and its processing capacity, so it is difficult to process a large amount of waste liquid continuously, and conversely the supply of waste liquid to the scrubber If the amount is too small, there is a problem that the waste liquid necessary for the scrubber treatment cannot be secured and the dust treatment cannot be performed sufficiently.

  Therefore, a main object of the present invention is to provide a processing system and a processing method capable of processing a waste liquid safely and stably.

In order to solve the above-described problems, the waste liquid to be treated is supplied to the treatment system of the present invention, and a pretreatment of the waste liquid is connected to the treatment apparatus, and the waste liquid after the pretreatment is treated. A spray drying device that removes solid content as a powder by spray drying and a scrubber that is connected to the spray drying device and performs dust treatment are provided. The scrubber is provided with a scrubber tank connected to the spray drying device, and a shower nozzle for ejecting a processing liquid into the scrubber tank, and the scrubber tank has a livestock liquid section for stocking the processing liquid. Forming and connecting the shower nozzle to both the treatment liquid source and the livestock part. Then, either or both of a clean processing liquid supplied from the processing liquid source and a used processing liquid supplied from the livestock liquid section can be ejected from the shower nozzle.
Further, in the treatment system of the present invention, it is more preferable that the dust-treated treatment liquid can be supplied without flowing back from the stock solution unit to the treatment apparatus.
The scrubber tank can be provided with a control means, and the control means can be designed to increase or decrease the supply amount from the processing liquid source so that the amount of the stock solution in the stock solution section can be kept constant.
Further, a plurality of processing systems as described above may be connected to construct a waste liquid connection circulation processing system. In this case, the waste liquid is supplied to one or more of the processing systems, and the processing is performed. The scrubber of the system is connected to a processing apparatus of one or more other processing systems, and the liquid generated by cooling the scrubber vapor is processed by the other processing system.
Further, in the waste liquid treatment method for performing waste liquid treatment using the treatment system as described above, the waste liquid is pretreated by the treatment device without flowing into the scrubber, and the waste liquid after pretreatment is spray-dried. Spray dry with equipment.
When the processing liquid in the livestock part is contaminated, the contaminated processing liquid can be transferred from the livestock part to the processing apparatus as waste liquid, and spray drying can be performed after processing in the processing apparatus.
It is more desirable to send the waste liquid from the treatment apparatus to the spray drying apparatus after the pH of the waste liquid is close to neutral.
It is desirable to perform spray drying in a state in which the temperature of the spray drying apparatus is maintained at 127 ° C. or higher to prepare the solid powder, and after collecting the powder from the spray drying apparatus, at a preset firing temperature. The post-processing to heat can be performed efficiently. The upper limit of the calcination temperature should not exceed the melting point of the component to be recovered, and the lower limit of the calcination temperature is the melting point of the impurity, the boiling point of the impurity, the decomposition temperature of the impurity, and the combustion temperature of the impurity. Of these, it is more desirable to set any one of the temperatures.
The waste liquid treatment method for performing waste liquid treatment using the above-described connected circulation treatment system is also suitable for treating radioactively contaminated water as the waste liquid.

  The exhaust gas from the spray dryer is processed by a scrubber, and the scrubber processing liquid circulates in the system, so that no harmful substances leak outside and high yields of target components such as metals from the waste liquid are obtained. Can be recovered. Since the waste liquid before being processed by the processing apparatus is not directly introduced into the spray drying apparatus and the scrubber, the spray drying apparatus and the scrubber are hardly corroded. The scrubber can be operated stably without being affected by the amount of waste liquid supplied. Since the fine powder can be obtained by using the treatment system of the present invention, post-treatment (firing etc.) of the collected powder is easy.

It is a figure showing typically the processing system (the 1st example) of the present invention. It is a figure which shows typically the processing system (2nd example) of this invention. It is an electron micrograph of a factory wastewater powder. It is a SEM-EDX chart which shows the elemental composition of a factory wastewater powder. It is a FTIR chart which shows the chemical composition of a factory wastewater powder. It is an XRD chart which shows the crystal structure of a factory wastewater powder. It is an electron micrograph of a nickel plating waste liquid powder. It is an electron micrograph of a chromium plating waste liquid powder. It is an electron micrograph which shows the change by baking of the nickel plating waste liquid powder. It is a SEM-EDX chart which shows the element change by baking of a nickel plating waste liquid powder. It is an electron micrograph of the nickel plating waste liquid powder after baking. It is a figure which shows the element mapping of the nickel plating waste liquid powder after baking. It is an electron micrograph which shows the change by baking of the chromium plating waste liquid powder. It is a SEM-EDX chart which shows the element change by baking of the chromium plating waste liquid powder. It is an electron micrograph of the chrome plating waste liquid powder after baking. It is a figure which shows the element mapping of the chromium plating waste liquid powder after baking. It is an XRD chart which shows the crystal structure of a nickel plating waste liquid powder. It is an XRD chart which shows the crystal structure of a chromium plating waste liquid powder. It is a FTIR chart of nickel and chromium plating waste liquid powder.

  Hereinafter, preferred embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, embodiment described below illustrates typical embodiment of this invention, and, thereby, the range of this invention is not interpreted narrowly.

<Processing system (first example)>
Reference numeral 1 in FIG. 1 represents a first example of the processing system of the present invention. The processing system 1 includes a processing device 10, a spray drying device 20 connected to the processing device 10, and a scrubber 40 connected to both the spray drying device 20 and the processing device 10. The waste liquid D treated in step 1 is dried by the spray drying apparatus 20, the exhaust gas of the spray drying apparatus 20 is treated by the treatment liquid L of the scrubber 40, and a part or all of the treatment liquid L used for the treatment is treated by the treatment apparatus. 10 can be supplied.
Hereinafter, each device will be described in detail.

(1) Processing device 10
The processing apparatus 10 has one or a plurality of processing tanks 11a to 11c. When there are a plurality of treatment tanks 11a to 11c, the treatment tanks 11a to 11c are connected to each other (in series or parallel connection), and one or more of the treatment tanks 11a to 11c is a waste liquid source such as a plating plant. 19, one or more other processing tanks 11c are connected to the spray drying device 20, and the waste liquid D supplied from the waste liquid source 19 to the processing tank 11a passes through the plurality of processing tanks 11a to 11c and is spray-dried. Supplied to the device 20.

  When the number of processing tanks is 1, the spray drying apparatus 20, the waste liquid source 19, and the scrubber 40 are connected to the same processing tank. That is, regardless of whether the number of the processing tanks 11a to 11c is 1 or plural, the waste liquid D and / or the processing liquid L is sent to the spray drying apparatus 20 after passing through the processing tanks 11a to 11c.

  The processing apparatus 10 performs pretreatment of the waste liquid D that passes through the processing tanks 11a to 11c. As the pretreatment, one or more of chemical treatment, dispersion treatment, and heat treatment is performed. For example, the addition means 13 is connected to one or more treatment tanks 11a to 11c, and the additive of the addition means 13 is added to the waste liquid D of the treatment tanks 11a to 11c to perform chemical treatment. The number and type of the adding means 13 are not particularly limited, but one or more additives (pH adjusting agent, separating agent for separating the solid content, etc.), particularly those capable of supplying the pH adjusting agent are desirable, and the additive is 2 In the case of seeds or more, they may be supplied to the same processing tanks 11a to 11c, or may be supplied to separate processing tanks 11a to 11c.

  For the dispersion treatment and the heat treatment, it is preferable to provide the stirring means 18 and / or the heating means 15 in one or more treatment tanks 11a to 11c. The stirring means 18 stirs the waste liquid D, and the heating means 15 heats the waste liquid D to a predetermined temperature (below the boiling point of the waste liquid D, for example, 80 ° C. or more and less than 100 ° C.). Therefore, the solid content and the additive are uniformly dispersed (dissolved) and / or the heated waste liquid D is supplied to the spray drying apparatus 20. In addition, when the waste liquid D contains contaminants, such as an organic solvent and a radioactive substance, or when contaminated gas like hydrogen sulfide is generated from the waste liquid D, it is desirable to seal the treatment tanks 11a to 11c. A duct 16 can be connected to the sealed treatment tanks 11a to 11c. Vapor generated by heating or the like may be directly discharged to the outside through the duct 16, but is preferably discharged to the scrubber 40 or other exhaust gas processing apparatus. The stirring means 18 is not particularly limited, and for example, a stirring blade, a magnetic stirring bar, an ultrasonic generator, or the like can be used alone or in combination.

(2) Spray drying device 20
The spray drying apparatus 20 includes a drying chamber 21 and a spray nozzle 22, and the spray nozzle 22 is attached to the drying chamber 21 with a jet port facing the inside of the drying chamber 21. The spray nozzle 22 is connected to the gas source 31 and the processing apparatus 10. The gas source 31 is supplied with compressed gas (for example, compressed air), and the processing apparatus 10 is supplied with the pretreated waste liquid D. The waste liquid D is compressed. It is blown off with air and becomes fine droplets that are ejected from the spray nozzle 22 into the drying chamber 21.

  The gas source 31 and the processing apparatus 10 are connected to the drying chamber 21 via a pipe, and any one or more of the pipe, the drying chamber 21, the spray nozzle 22, and the gas source 31 are heated by the heating unit 32. As a result, the waste liquid D is heated before and / or after the ejection, and the solvent (water or organic solvent) is efficiently evaporated from the droplets of the waste liquid D to separate the particulate solid, and the solid particles are dried. Released into the chamber 21.

  In order to efficiently evaporate the waste liquid D, the drying chamber 21 is provided with either one or both of the heating means 32 and the heat retaining means. The heat retaining means is, for example, a heat insulating material and covers a part or the whole of the drying chamber 21 to keep the heat. An electric heater may be used as the heating means 32. For example, if the heat pipe 39 is wound around the drying chamber 21 and the heat drainage of the heating means 32 (heat source, for example, other factory equipment) is supplied to the heat pipe 39, The drying chamber 21 can be efficiently heated while suppressing the energy cost. The heat pipe 39 and the electric heater can be used in combination. If the amount of heat from the heat pipe 39 is insufficient, the electric heater may be used as an auxiliary.

  Moreover, it is preferable that the gas source 31 is also provided with a heating means (not shown) for heating the compressed gas, and the waste liquid D is sprayed with hot air. In order to spray-dry the waste liquid D efficiently, a control device 36 for controlling both the hot air temperature and the temperature of the drying chamber 21 is provided. The control device 36 is connected to the heating means of the gas source 31 and the heating means 32 of the drying chamber 21, and controls the energization amount and the heat drainage flow rate to these heating means 32 based on the measurement results of the hot air temperature and the drying chamber 21 temperature. . In the temperature measurement, for example, the temperature inside the spray nozzle 22 is regarded as the hot air temperature, and the temperature at the center position inside the drying chamber 21 is regarded as the internal temperature of the drying chamber 21.

  When treating the waste liquid D such as industrial waste water, it is not necessary to dry at low temperature because inorganic materials such as metals are the main substances to be removed. Therefore, it is desirable to use a heating means 32 that can be heated at a high temperature (eg, hot air temperature is 181 ° C. or higher and drying chamber temperature is 127 ° C. or higher), and a decompression device (vacuum pump or the like) for low temperature spray drying is used. It is unnecessary.

  The drying chamber 21 is connected to the scrubber 40 directly or via the cyclone 25. The lower portions of the drying chamber 21 and the cyclone 25 are accumulation units 23 and 26, and solid particles are collected in the accumulation unit 23 of the drying chamber 21, or a part or all of them are sent to the cyclone 25. Are collected in the accumulating unit 26. Solid particles M (powder) are taken out of the processing system 1 through valves (doors) (not shown) of the collecting units 23 and 26 or by separating the collecting units 23 and 26 from the processing system 1, and are disposed in a waste tray. Etc. can be recovered. On the other hand, the compressed gas ejected into the drying chamber 21 is sent to the scrubber 40 directly or through the cyclone 25 as exhaust gas.

  If the inside of the cyclone 25 is at a low temperature, the waste liquid D that has not been dried in the drying chamber 21 does not dry, and deliquescence of the dried powder may occur. It is desirable to provide a heating means and maintain the temperature of the cyclone 25 (for example, the temperature at the center position inside the cyclone 25) at a desired temperature with a control device or the like.

(3) Scrubber 40
The scrubber 40 has a scrubber tank 41 and a shower nozzle 42, and the shower nozzle 42 is attached to the upper part of the scrubber tank 41 with its outlet facing the inside of the scrubber tank 41. The exhaust pipe 28 that connects the spray drying device 20 to the scrubber 40 is connected to the scrubber tank 41 below the jet nozzle of the shower nozzle 42, and the exhaust gas from the spray drying device 20 falls from the shower nozzle 42. A scrubber treatment (dust removal) is made in contact with the liquid L.

  The part below the connection position of the exhaust pipe 28 of the scrubber tank 41 is liquid-tight, and is a livestock solution part 43 capable of stocking the treatment liquid L. Outside the scrubber tank 41, a processing liquid source 35 for supplying a clean processing liquid L (liquid having a pH of 5.8 to 8.6, for example, tap water) is disposed. The shower nozzle 42 is connected to both the processing liquid source 35 and the livestock liquid part 43, and the cleansing liquid before contact with the exhaust gas and / or the processing liquid L which has been stored as livestock is ejected from the shower nozzle 42. Then, the used processing liquid L obtained by scrubbing the exhaust gas is accumulated in the livestock liquid portion 43.

  Since the treatment liquid L in the livestock liquid part 43 is returned to the shower nozzle 42 by the pump 37 or the like and is ejected from the shower nozzle 42 again, the treatment liquid L circulates in the scrubber 40. The scrubber 40 is provided with a control means 45 for controlling the amount of the livestock fluid part 43. The control unit 45 includes, for example, a sensor 48 that detects the liquid surface height (or the amount of livestock liquid) of the processing liquid L. When the detection value of the sensor 48 is less than a set value (setting range), the processing liquid source 35 is used. Is started (or the supply amount is increased), and when the detected value exceeds the set value (setting range), the supply from the processing liquid source 35 is stopped (or the supply amount is decreased). Therefore, the amount of the stock solution of the processing liquid L is always constant, and the liquid level is maintained at the set height.

  It is desirable to connect an overflow drain pipe 47 to the scrubber tank 41 in preparation for an abnormal situation that cannot be controlled by the control means 45. For example, the drain pipe 47 is connected to the scrubber tank 41 at a position higher than the set liquid level and lower than the connection position of the exhaust pipe 28. Since the processing liquid L exceeding the set liquid level flows out from the drain pipe 47, the processing liquid L does not flow into the spray drying apparatus 20 through the exhaust pipe 28.

  In addition to the overflow drain pipe 47, it is desirable to connect a treatment liquid replacement drain pipe 46 to the livestock solution section 43. These drain pipes 46 and 47 are connected to the same or different treatment tanks 11a, so that the treatment liquid L in the livestock solution unit 43 is not only circulated in the scrubber 40 but also can be supplied to the treatment apparatus 10. Yes.

  As described above, in the processing system 1 of the present invention, the processing liquid L is supplied from the scrubber 40 to the processing apparatus 10, but the waste liquid D is not directly supplied from the processing apparatus 10 to the scrubber 40, and the scrubber 40 and the spray drying apparatus. 20 is always supplied with the waste liquid D (steam, solid content) after being treated in the treatment tanks 11a to 11c. Therefore, when the corrosive waste liquid D is treated, the metal parts of the scrubber 40 and the spray drying apparatus 20 are not corroded, and the machine life is extended. In addition, if the backflow prevention means 39 such as a check valve is provided between the scrubber 40 and the processing apparatus 10, for example, in the drain pipes 46 and 47, the waste liquid backflow to the scrubber 40 can be more reliably prevented.

  It is also possible to connect a discharge pipe 49 to the scrubber tank 41 and discharge the gas in the scrubber 40 to the outside directly or through a filter or the like. If the discharge pipe 49 is connected to the scrubber tank 41 above the jet nozzle of the shower nozzle 42, the exhaust gas before the scrubber treatment can be prevented from being discharged to the outside. On the other hand, if the duct 16 of the processing apparatus 10 is connected to the scrubber tank 41 below the jet nozzle of the shower nozzle 42, the vapor of the processing apparatus 10 contacts the processing liquid L to remove contaminants and the like. Therefore, the vapor containing pollutants is not released directly to the outside.

Next, a waste liquid processing method using the processing system 1 of the first example will be described.
<Waste liquid treatment method (first example)>
A factory facility such as a plating plant or an experimental facility such as a university is used as a waste liquid source 19, and a waste liquid D (for example, a strong acid or strong alkaline waste liquid such as a plating waste liquid) is supplied from the waste liquid source 19 to the processing apparatus 10. When there are a plurality of treatment tanks 11a to 11c, the waste liquid D and the treatment liquid L are mixed in the first treatment tank 11a, and then the additive is added in the second and subsequent treatment tanks 11b and 11c.

  As an additive, a pH adjuster, a separating agent, and other additives (dispersing agent, etc.) as necessary are added to the same processing tank 11b or separate processing tanks 11a to 11c. A pH adjusting agent (neutralizing agent such as acid or alkali, pH buffering agent, etc.) brings the pH of the waste liquid D close to neutral, and makes it weak acid to weak alkali (pH 5.0 to 9.0). The dispersant uniformly disperses the solid content. A separating agent is not essential, but is particularly necessary when the component to be separated is dissolved in the waste liquid and is difficult to recover.

  That is, the waste liquid D processed by the processing apparatus 10 is a weak acid to a weak alkali, and the target substance is dispersed as a solid content, and the spray drying apparatus 20 is not damaged by a strong acid, a strong alkali, or the like. The material can be dry separated as a solid. Therefore, it is not necessary to use strong acid / alkali resistant materials (SUS316, etc.) for the materials of each device 10, 20, 40, and general materials (SUS304, SUS430, aluminum, etc.) can be widely used. .

  In addition, in order to raise the collection | recovery efficiency in the spray drying apparatus 20, the waste liquid D after adding an additive is heated to 80 degreeC or more and less than 100 degreeC with the processing tank 11c, and is sent to the spray drying apparatus 20. FIG. If there is a possibility that steam or pollutant gas may be generated from the waste liquid D, the valve of the duct 16 is opened, and the processing tanks 11a to 11c that may cause the waste liquid D to evaporate are connected to the scrubber 40. Steam (contaminated gas) is processed by the scrubber 40 without leaking into the atmosphere.

  If the drying chamber 21 is heated (or kept warm) during spray drying, the waste liquid D can be evaporated without being liquefied and the solid content can be separated. Here, when the temperature of the drying chamber 21 or the cyclone 25 is low (the hot air temperature is less than 181 ° C., the drying chamber temperature (center temperature) is 125 ° C. or less, the cyclone temperature (center temperature) is 102 ° C. or less), It hardens into putty and does not become a fine powder. Therefore, during spray drying, it is desirable to maintain the hot air temperature at 181 ° C. or higher, the drying chamber 21 temperature at 127 ° C. or higher, and more preferably the cyclone 25 temperature at 105 ° C. or higher. In order to stably produce fine powder, it is more desirable to set the hot air temperature to 187 ° C. or higher.

  If the temperature is above, liquefaction of the powder does not occur, but if there is a possibility that liquefaction may occur in part due to uneven temperature or sudden failure of the device, the drain is provided in one or both of the drying chamber 21 and the cyclone 25. A pipe (not shown) is connected, and the liquefied vapor is discharged to the processing apparatus 10 and / or the scrubber 40. Since the solid particles obtained by spray drying are fine powder, they can be easily discarded as industrial waste, and can be easily recovered from the accumulating units 23 and 26 and reused as raw materials without being discarded. is there. The powder can be directly reused. However, if the impurity concentration of the powder is high, the powder is used after being subjected to post-processing described later.

  During spray drying, the valve of the exhaust pipe 28 is opened, the spray drying apparatus 20 and the scrubber 40 are connected, and the processing liquid L is circulated in the scrubber 40. Although the circulation procedure is not particularly limited, for example, just before the start of spray drying or immediately after the start, when only the treatment liquid L is supplied from the treatment liquid source 35 and the treatment liquid L is stocked to some extent in the livestock part 43, The processing liquid L is circulated from the stock solution section 43 to the shower nozzle 42.

  During the scrubber process, the amount of the livestock solution of the process liquid L is maintained constant by the control means 45 described above. Together with (or separately from) the control by the control means 45, if the valve of the overflow drain pipe 47 is opened and the scrubber 40 and the processing apparatus 10 are connected by the drain pipe 47, the moisture-increasing treatment liquid L can be obtained. Overflow from the drain pipe 47. In any case, since the liquid level of the processing liquid L is kept constant during the scrubber process, the amount of ejection from the shower nozzle 42 is stabilized, and the backflow of the processing liquid L to the spray dryer 20 side is prevented. Is done.

  The exhaust gas of the spray drying apparatus 20 and the steam of the processing apparatus 10 come into contact with the processing liquid L in the scrubber 40, and the solid content (dust) in the exhaust gas is supplemented by the processing liquid L, so that the pollutant in the steam (contaminated gas) ) Is mixed (dispersed, dissolved) in the processing liquid L and supplemented, and falls into the livestock liquid part 43 (scrubber processing). Thus, even if the exhaust gas or the steam is contaminated, the contaminant is captured by the processing liquid L and falls to the livestock fluid part 43, so that clean steam from the processing liquid L is released from the discharge pipe 49. Even so, the contaminated vapor and the contaminated exhaust gas before the scrubber treatment are not released from the discharge pipe 49.

  The solids and contaminants that have fallen into the livestock liquid part 43 do not flow out to the outside and circulate in the scrubber 40 together with the treatment liquid L, so that the concentration of solids and contaminants in the treatment liquid L increases as the treatment time increases. Becomes higher. If these concentrations become too high, problems such as load on the pump 37, clogging of the shower nozzle 42, and pH drop (or pH rise) of the treatment liquid L due to contaminants occur, so when a preset treatment time has elapsed. Alternatively, when the solid content concentration and the contaminant concentration of the treatment liquid L become higher than the set values, the spray drying and the scrubber treatment are stopped and the contamination treatment liquid L is replaced.

  The exchange of the contaminated treatment liquid L is performed by opening the valve of the replacement drain pipe 46 and connecting it to the livestock solution unit 43 and the treatment apparatus 10 and discharging the contaminated treatment liquid L to the treatment tank 11a of the treatment apparatus 10. When a part or all of the contaminated processing liquid L is discharged, the valve of the drain pipe 46 is closed to shut off the livestock fluid part 43 from the processing apparatus 10, and the processing apparatus 10 treats the contaminated processing liquid L as the waste liquid D and sprays it. Dry and scrubber.

  As described above, since the waste liquid D can be processed in the processing system 1 without carrying the contaminated processing liquid L to the outside, the processing can be performed in the closed system without any contaminants flowing out to the outside. Moreover, since the solid content is separated from the exhaust gas generated by spray drying and returns to the processing apparatus 10 together with the processing liquid L and is processed as the waste liquid D, the recovery rate of the target substance becomes extremely high. When the processing system 1 of the first example or the processing system of another example (for example, a connected circulation system 2 described later) is used, the processing liquid L is contaminated so that it cannot be reprocessed by the processing apparatus 10. Only when it is discharged to the outside, it is processed by another processing device.

<Post-processing>
When the waste liquid D contains a reusable component (metal or the like), a post-treatment for extracting the target component from the powder collected from the accumulating units 23 and 26 can be performed. The post-treatment is not particularly limited, but the temperature is lower than the melting point of the target component to be recovered and the impurities are melted, evaporated, decomposed or burned and separated from the solid (target component), that is, the melting point, boiling point, decomposition temperature or combustion temperature. In this way, since the impurities can be separated from the target component (solid phase) as a liquid phase or a gas phase, the impurities can be removed by a simple combustion treatment. If the powder is a porous particle, if the impurity is in the liquid phase, it may be trapped in the powder by capillary force, so the firing temperature should be higher than the boiling point, decomposition temperature or firing temperature of the impurity, and the impurity should be removed as a gas. Is more desirable.

  If the baking treatment is performed in an oxygen-containing atmosphere (for example, in the air), organic compounds among the impurities can be efficiently burned and removed. When two or more kinds of target components having different melting points are contained in the powder, the lower melting point may be adopted as the upper limit of the firing temperature. When two or more impurities having different melting points (more preferably boiling points), decomposition temperatures or combustion temperatures are mixed, the higher melting point (boiling point), decomposition temperature or combustion temperature, and the melting point of the target component A lower temperature is adopted as the lower limit.

  The optimum range of the combustion temperature can be determined by examining the composition of the powder before firing. The composition is measured by EDX (energy dispersive X-ray spectroscopy, attached to scanning or transmission microscope), infrared spectroscopy (IR method), X-ray diffraction method (XRD), atomic absorption spectrometry ( Known measurement methods such as AAS) and inductively coupled plasma method (IPC) can be used. Since the powder obtained by the present invention is a microparticle or a collection of microparticles having a particle diameter of several μm (easily decomposed by physical impact), in particular, EDX, IR (FTIR: Fourier transform infrared spectroscopy) Easy sample preparation for powder XRD and IPC.

  It is desirable to investigate both elemental composition and molecular structure by combining a plurality of the above measuring methods (for example, EDX, XRD, and FTIR). The composition of the powder does not necessarily need to be measured for all of the recovered powder. The composition is measured for each type of waste liquid D, and the measurement result is used for another processing lot (powder) obtained from the same type of waste liquid. You can also. In addition, when it is difficult to determine the composition of impurities by a normal measurement method, it is desirable to conduct a combustion test in which the heating temperature is changed in advance and to investigate the optimum combustion temperature of the powder beforehand for each type of waste liquid D.

  The post-treatment is not limited to the calcination treatment, and chemical treatment may be performed in which the powder is immersed in a reaction solution (for example, strong acid, strong alkali, etc.) that decomposes or dissolves impurities and leaves only the target component. If the chemical treatment is performed while heating the reaction solution to less than 100 ° C., impurities can be removed in a shorter time. Measurement of the powder composition can also be used to determine the components of the reaction solution.

  The chemical treatment can be combined with the baking treatment instead of being performed alone. For example, chemical treatment is performed either before or after firing, or both, and the impurities are chemically separated (decomposed, reduced, etc.) from the target component and then fired, or impurities remaining after firing are treated by chemical treatment. It can also be removed. The chemical treatment may be performed by changing the components of the reaction solution before and after the firing treatment, or the chemical treatment and the firing treatment may be repeated a plurality of times. The powder obtained by the present invention is a porous fine particle and has a large specific surface area. Therefore, the contact area with the reaction solution is large, and the heating efficiency is also high. Therefore, any post-treatment of baking treatment and chemical treatment can be performed efficiently.

  Since the powder after the post-treatment has a reduced impurity concentration, the target component can be reused directly or through Yamamoto reduction. For example, when the powder is subjected to Yamamoto reduction, if sulfur (S) remains, it is difficult to perform the treatment. Therefore, it is desirable to perform post-treatment until at least sulfur is removed.

Although the case where the waste liquid D and the processing liquid L are circulated in one processing system 1 has been described above, the present invention is not limited to this, and a single waste liquid using a plurality of processing systems 1. Processing can also be performed. The processing system (connected circulation processing system) of the second example of the present invention will be described below.
<Linked circulation processing system>

Reference numeral 2 in FIG. 2 indicates a connected circulation processing system. The connected circulation processing system 2 is formed by connecting a plurality of units 1 ′, 1 ₁ , 1 ₂ having a processing device 10, a spray drying device 20, and a scrubber 40. The device configuration of each unit 1 ′, 1 ₁ , 1 ₂ is not particularly limited, and the same one as that of the processing system 1 of the first example can be used, but here, the connection of the waste liquid source 19 and the discharge pipe 49 The connection method is different from the processing system 1 of the first example. Hereinafter, the same apparatus (member) as the processing system 1 of the first example is denoted by the same reference numerals as those used in FIG.

In the connected circulation processing system 2, it is not necessary to connect the waste liquid source 19 to all the units 1 ′, 1 ₁ , 1 ₂ . The waste liquid source 19 is connected to only one or more selected units 1 ′ (upstream unit) among the plurality of units 1 ′, 1 ₁ , 1 ₂ , and the discharge pipe 49 is not provided in the scrubber 40 of the upstream unit 1 ′. (Or the discharge pipe 49 is not opened), the entire unit 1 ′ is shut off from the external atmosphere (air).

In the scrubber 40 of the upstream unit 1 ′, the connecting pipe 51 is connected to the scrubber tank 41 instead of the discharge pipe 49, and the scrubber 40 is connected to the unit 1 ₁ (downstream) to which the waste liquid source 19 is not connected via the connecting pipe 51. Unit). The vapor discharged from the scrubber 40 of the upstream unit 1 ′ is cooled by natural cooling or a cooling device (not shown) while passing through the connecting pipe 51, becomes a liquid, and is sent to the processing device 10. That is, the downstream unit 1 _1, rather than waste D from waste source 19 to process the release vapors of the upstream unit 1 'as waste.

Unit 1 ', 1 number ₁ are two case (upstream, downstream of the 1), upstream unit 1' downstream unit 1 ₁ immediately may be provided discharge pipe 49, but a high pollution level liquid waste D when processing is provided downstream units 1 _1, 1 ₂ the two or more is in the downstream unit 1 ₁ of the upstream unit 1 'side, (without opening or discharge pipe 49) without providing the discharge pipe 49, discharge pipe connect the connecting pipe 51 instead of 49, for connecting the scrubber 40 to the processing unit 10 of the other downstream unit 1 _2. In this case, the steam scrubber 40 downstream unit 1 ₁ is released, will be processed by the other downstream unit 1 _2.

That is, the upstream unit 1 'downstream unit 1 ₁ of the first unit that is connected to the upstream unit 1' to process steam, one second is the downstream unit 1 second unit of the downstream unit 1 ₂ connected to _a one undereye processing the flow unit 1 ₁ of the steam, n-1 single th downstream units _n of n base-th, which is connected to the downstream unit _n-1 of the processes the n-1 single th unit _n-1 of the steam (n is Any integer).

The steam generated in the first scrubber 40 is processed for the number of downstream units 1 ₁ and 1 ₂ (n times), and the pollutant concentration decreases. It is desirable that the number of repetitions in which the pollutant concentration is sufficiently low is obtained in advance by an experiment or the like, and the downstream units 1 ₁ and 1 _{2 corresponding} to the number (n units) are connected. In this case, the last (n stand th, where second unit) by opening the discharge pipe 49 rather than the downstream unit 1 _2, connecting pipe 51, connected to the outside atmosphere through a scrubber 40 directly or filter. The vapor discharged from the discharge pipe 49 has a sufficiently low pollutant concentration, so that problems such as air pollution do not occur.

In each unit 1 ′, 1 ₁ , 1 ₂ , the drain pipes 46, 47 of the livestock solution unit 43 may be connected to the processing device 10 of the same unit 1 ′, 1 ₁ , 1 ₂ , or other The units 1 ′, 1 ₁ , and 1 ₂ may be connected to the processing apparatus 10; When the treatment liquid in the livestock liquid part 43 is contaminated at a high concentration, it is desirable to connect the drain pipes 46 and 47 to the treatment apparatus 10 of the upstream unit 1 ′ to treat the treatment liquid as waste liquid.

<Waste liquid treatment method (second example)>
Next, a waste liquid processing method (second example) using the connected circulation processing system 2 will be described. The waste liquid treatment method of the second example is particularly suitable for the treatment of the waste liquid D containing a high concentration of contaminants or the waste liquid D containing highly toxic contaminants, for example, radioactive contaminated water containing radioactive substances. . Here, radioactively contaminated water includes wastewater from nuclear reactors and spent fuel storage facilities, wastewater discharged after decontamination of soil and buildings, radioactively contaminated river water, seawater, lake water, sewage, and the like.

  In the waste liquid treatment method of the second example, radioactively contaminated water is sent from the waste liquid source 19 (reactor or the like) to the treatment device 10 of the upstream unit 1 ′. In this case, an adsorbent (separating agent) of a radioactive substance such as cesium, strontium, or iodine is used as an additive. The adsorbent is not particularly limited, and known ones can be widely used, but a cation adsorbing substance and a porous substance are preferable, and specifically, zeolite, layered silicate, Prussian blue, and the like. Adsorbents may be used alone or in combination of two or more.

  If the radioactively contaminated water is a strong alkali or strong acid, or if the adsorption efficiency is poor at the same pH, a pH adjuster is added in addition to the adsorbent, and the pH of the radioactively contaminated water is reduced from weak acid to weakly alkaline (or Adsorption optimum pH). Moreover, you may add other additives, such as a dispersing agent which improves the dispersibility of adsorption agent. In any case, the adsorbent (solid content) on which the radioactive material is adsorbed can be separated and dried without damaging the apparatus, and the exhaust gas contaminated with the radioactive material is treated by the scrubber 40. Does not flow out.

The radioactive material adsorbents described above are used in the downstream units 1 ₁ and 1 ₂ alone or together with other additives. Even if radioactive material is mixed into the steam generated by decontamination, the steam is decontaminated in the downstream units 1 ₁ and 1 ₂ , so that only the sufficiently decontaminated steam (gas) is released from the discharge pipe 49. Will be.

In conventional decontamination equipment that combines adsorption towers and filters, radioactive materials may leak into the gas (vapor) released from the equipment. To prevent the leakage of radioactive materials, the equipment structure However, there was a problem that it was complicated and large. On the other hand, the connected circulation processing system 2 of the present invention has a relatively simple device structure, and also changes the connection of the connection pipe 51 by a simple method such as valve switching, detachment, connection, and the like. The number of 1 ₁ and 1 ₂ can also be changed.

That is, it is possible to change the number of units 1 ′, 1 ₁ , 1 ₂ to be connected according to the contamination level of the waste liquid (radiocontaminated water), so that various waste liquids (radiocontaminated water) with low to high contamination levels can be obtained. It is possible. In addition to the units 1 ′, 1 ₁ and 1 ₂ to be used, a spare unit is prepared, and the contamination level (radiation dose) detected by the last (n-th) scrubber 40 is higher than the reference value. In this case, the discharge pipe 49 of the scrubber 40 is closed and the connecting pipe 51 is opened to connect to the spare unit, so that the steam of the scrubber 40 can be decontaminated. The spare unit is not particularly limited, but one or a plurality of the same units as the downstream units 1 ₁ and 1 ₂ can be used.
Next, a waste liquid treatment example using the treatment system 1 of the present invention will be described more specifically.

  A 1/5 model processing system 1 testing machine of a practical machine (processing capacity 500 liter (l) / day) was prepared. The processing capacity of this testing machine is 215 ml / min (about 103 liters (l) / day when operated 8 hours a day). As waste liquid D, factory wastewater from a metal processing factory and plating waste liquid (nickel plating waste liquid, chrome plating waste liquid) were used, and powders were collected after pretreatment and spray drying treatment.

As pretreatment, the waste liquid D was introduced into the treatment apparatus 10 and neutralized using a pH adjuster (aqueous sodium hydroxide solution). As for the chromium plating waste liquid, hexavalent chromium was reduced to trivalent chromium by adding sodium bisulfite (NaHSO ₃ ) before neutralization. Hexavalent to trivalent reduction was performed in a strong acid solution at pH 3, followed by neutralization (pH 6.2).

For spray drying, the product name “TSK-52” manufactured by Takezuna Seisakusho Co., Ltd. is used as a hot air generator. Spray dryer temperature (center temperature of drying chamber) is 127 ° C., cyclone temperature (center temperature of cyclone) It carried out on the conditions of 105 degreeC. Industrial wastewater was sprayed under conditions of air pressure 1.3 kg / m ³ , waste liquid supply rate 215 ml / min, and air supply rate 85 l (l) / min. The nickel plating waste liquid and the chrome plating waste liquid containing more organic substances were sprayed under the conditions of an air pressure of 1.5 kg / m ³ , a waste liquid supply amount of 120 ml / min, and an air supply amount of 96 liters (l) / min. The obtained powder was collected from the accumulating parts 23 and 26 and subjected to “analysis test of fine structure and elemental composition”, “chemical composition test”, and “crystal structure test”. In addition, the use apparatus and test conditions of each test are as follows.

<Analysis of microstructure and elemental composition>
Equipment: Scanning electron microscope (SEM, product name “JSM-6320F” manufactured by JEOL Ltd.), energy dispersive X-ray analyzer (EDX, product name “JED-2300F” manufactured by JEOL Ltd.) ")
Accelerating voltage: 15kV

<Chemical composition>
Equipment: Fourier transform infrared spectrophotometer (product name “JIR-WINSPEC50” manufactured by JEOL Ltd.)
Measuring method: Measuring method: Total reflection (ATR) method (product name “DuraScope” manufactured by SENSIR Technologies)
Measurement wave number: 600-4000cm ^-1
Resolution: 4cm ^-1
Integration count: 32 times

<Crystal structure>
Equipment: X-ray diffractometer (product name “X 'Part-PRO” manufactured by Philips)
Voltage: 45kV
Current: 40mA
Measuring range: 10-100 °

The test results are shown below.
<Heating temperature>
In any case of industrial wastewater, nickel plating waste liquid, and chromium plating waste liquid, only powder is recovered from the accumulating sections 23 and 26 under the condition that the internal temperature of the spray drying apparatus 20 is 127 ° C. and the internal temperature of the cyclone 25 is 105 ° C. It was. When the temperature of the spray drying apparatus 20 was set to 125 ° C. or lower and the temperature of the cyclone 25 was set to 102 ° C. or lower, a large amount of sludge waste liquid was mixed in the accumulating sections 23 and 26, and powderization was not normally performed. From the above, it can be seen that the minimum heating temperature required for powder recovery is 127 ° C. for the spray dryer 20 and 105 ° C. for the cyclone 25. This minimum heating temperature is a temperature that can be sufficiently achieved by a combination of factory exhaust heat and hot air without separately providing an electric heater or the like. The amount of powder recovered from 7.4 kg of the nickel plating waste liquid is 250 g, and it can be seen that the metal recovery rate is high when the processing system 1 of the present invention is used.

<Microstructure>
3 (a) and 3 (b) show SEM images of powder obtained from factory wastewater, and Fig. 7 (a) and (b) show SEM images of powder obtained from nickel plating waste liquid. SEM images of the obtained powder are shown in FIGS. 8 (a) and 8 (b), respectively.

  As can be seen from FIGS. 3 and 8, the powder (factory wastewater, chrome plating waste liquid) obtained by setting the spray drying apparatus 20 to 127 ° C. or higher was fine particles having a diameter of 1 μm to 30 μm. Although the nickel plating waste liquid appears to have a diameter of 100 μm or more, it can be seen from FIG. 7B that the powder is an aggregate of fine particles having a diameter of less than 10 μm. Actually, when a physical impact was applied to the powder, it was easily decomposed into fine particles.

  Moreover, it can be seen from the SEM images of FIGS. 3B and 8B that the powder particles are aggregates of nanoparticles having a diameter of less than 1 μm. In fact, even when physical impact was applied to these powder particles, the nanoparticles were broken apart. Therefore, it was confirmed that an aggregate of nanoparticles (porous powder) can be obtained from various types of waste liquid D by using the treatment system 1 of the present invention.

<Results of analysis of powder obtained from factory effluent>
The measurement results of the elemental composition of the powder are shown in FIG.

  As can be seen from FIG. 4 and Table 1 above, the element peaks are Na, S, Cl, Fe, Si, Ca, etc., and the treatment system 1 of the present invention is not limited to heavy metals, but various types such as Na, Si, Ca, etc. It was confirmed that it is suitable for the recovery of inorganic compounds.

Looking at the EDX atomic ratio in FIG. 4, the amount of Na (61.5%) is the sum of the amount of Cl (9.1%) twice the amount of S (22.8%) (54.7%) It agrees with sodium sulfate (Na ₂ SO ₄ ) and sodium chloride (NaCl) appearing in the X-ray diffraction spectrum of FIG. In addition, the presence of nitrate ions can be seen from the infrared absorption spectrum of FIG. From this, it can be seen that the factory effluent used in the test contains sodium sulfate, sodium chloride and nitric acid, and it can be seen that the treatment system 1 of the present invention can also be used to recover various salts.

<Results of analysis of powder obtained from plating waste liquid>
FIG. 10 (a) shows the measurement results of the elemental composition of the powder obtained from the nickel plating waste liquid, and Table 2 shows the measurement results of the elemental composition of the powder obtained from the chrome plating waste liquid. Show.

  10 (a), FIG. 14 (a), Tables 2 and 3, the composition of the powder before firing is Na, P, S, Ni in the nickel plating waste liquid, and Na, S, Cr in the chromium plating waste liquid. It was confirmed that metal recovery using the processing system 1 was possible regardless of the type of plating waste liquid.

Next, the powder obtained from the plating waste liquid was subjected to a post-treatment (firing test) under the following conditions. <Baking test>
Equipment: High-temperature atmosphere furnace (trade name “KB-9814-VP” manufactured by Koyo Lindberg Co., Ltd.)
Firing atmosphere: Air (powder is fired in a crucible)
Firing temperature: 1000 ° C, 1500 ° C or 1550 ° C
Baking time: 1 hour (1550 ° C only 3 hours)

<Firing test result of Ni sample>
FIGS. 9A to 9C show electron micrographs (SEM) before and after firing the powder (Ni sample) of the nickel plating waste liquid. The Ni sample before firing is in an agglomerated state (aggregate) and remains at the original agglomerated state at 1000 ° C. (FIG. 9B), but is melted at 1500 ° C. (FIG. 9C). ). However, since the surface of the crucible containing the powder also melted at 1500 ° C., the molten Ni sample was melted into the surface of the crucible.

  The result of analyzing the composition change at this time by SEM-EDX is shown in FIGS. Na, P, and S remain at a calcination temperature of 1000 ° C., but the peak of S decreases, indicating that sulfur has been removed. On the other hand, at the firing temperature of 1500 ° C, the crucible surface has melted and Al, Si, K, Ca, etc., which are constituent elements of the crucible, appear, but on the other hand, the S peak disappears and the Na peak also decreases. The residue from the Ni sample has about 82.53% P and about 17.47% Ni.

  Moreover, when element mapping (FIG. 12) regarding the nickel plating waste liquid powder (Ni sample) baked at 1500 ° C. is seen, it can be seen that Ni, P, and Ca are distributed in the particulate portion. Of these, Ni and P are elements originally contained in the Ni sample, and P remains in Ni even after firing at 1500 ° C. On the other hand, Ca is thought to have been dissolved from the crucible. From this, it was clarified that the particulate portion was formed by melting the Ni sample, and Na and S were removed by firing at 1500 ° C., but P still remained.

The X-ray diffraction spectrum and FTIR chart of the Ni sample before firing are shown in FIGS. 17 and 19, respectively. From the appearance peak of FIG. 17 (30 to 30 °, about 23 °, about 25 °) and the result of the elemental composition of FIG. 10A, it is presumed that sodium sulfate exists as a crystal phase before firing. Further, from the chart of FIG. 19, it is estimated that the Ni sample before firing contains at least nitrate ions (NO ₃ ⁻ ) and sulfate ions (SO ₄ ²⁻ ). Therefore, it is estimated that the Ni sample before firing contains sodium sulfate and sodium nitrate as impurities.

  Sodium sulfate has a melting point of 884 ° C., sodium nitrate has a melting point of 308 ° C., a boiling point of 380 ° C. (decomposition), and nickel (target component) has a melting point of 1445 ° C. As described above, since the peak of S is small at a firing temperature of 1000 ° C., the target component (nickel is removed while removing impurities at a firing temperature of not less than the impurity melting point (884 ° C.) and less than the target component melting point (1445 ° C.). ) Was recovered.

  It is said that Ni Yamamoto's reduction treatment is preferred to have a Ni content of 5% by weight or more and a minimum amount of residual sulfur (Research on model circulation system associated with recycling of plating sludge, March 2005, Economy Ministry of Industry). In the post-treatment (firing) described above, S is removed from the Ni sample and the Ni concentration becomes high (about 17.47%), so that it can be sufficiently used for the Yamamoto reduction treatment. If the firing temperature is too high, a crucible component (Ca or the like) is mixed in, but this can be prevented by using a high heat-resistant crucible such as high-purity alumina. Further, P remaining in the Ni sample after firing can also be removed by chemical treatment after firing.

<Results of firing test of Cr sample>
FIGS. 13A to 13C show electron micrographs (SEM images) of Cr samples before firing and after firing at 1000 ° C. and 1500 ° C. FIG. In the Cr sample, the shape of the powder particles has already changed at 1000 ° C. At 1500 ° C, the fine particle structure of 1 µm or less has disappeared and the surface has changed to a smooth state. The result of having analyzed the composition change by SEM-EDX at this time is shown to Fig.14 (a)-(c). It can be seen that the peak of Cr increases as the firing temperature rises, Na and S decrease, and impurities (Na, S, etc.) are removed leaving Cr as the target component. However, Na and S that disappeared after firing at 1500 ° C. in the Ni sample remained after firing at 1500 ° C. in the case of the Cr sample.

  Therefore, the temperature was further raised to 1550 ° C., and the firing time was extended from 1 hour to 3 hours. FIGS. 15 and 16 (a) to 16 (c) are SEM images and element mapping of the sample fired at 1550 ° C. In this case as well, the surface of the crucible is affected by the melting of the crucible surface as in the case of 1500 ° C. of Ni. Cr sample is dissolved in the sample. However, the elemental mapping in FIG. 16 shows that the central square lump is almost free of Na and S, indicating that Na and S are removed from Cr by firing at 1550 ° C.

The X-ray diffraction spectrum and FTIR chart of the Cr sample before firing are shown in FIGS. 18 and 19, respectively. For comparison with the Ni sample, the baseline of the Cr sample is increased by 0.5 (absorbance) in FIG. From the appearance peak of FIG. 18, it is presumed that sodium sulfate was present as the crystal phase before firing, and sulfate ions (SO ₄ ²⁻ ) were present from the chart of FIG. 19. Therefore, it is presumed that the Cr sample before firing contains at least sodium sulfate (melting point: 884 ° C.) as an impurity. However, since more Na and S remain than Ni samples after firing at 1500 ° C., it is high in addition to sodium sulfate. Presumed to contain melting point impurities.

  Since the boiling point of Cr is 1907 ° C and Na and S are removed at least at 1550 ° C, the Cr sample can be recovered with high purity at a firing temperature of 1550 ° C or higher and lower than 1907 ° C. Recognize. As in the case of nickel, melting of the crucible and mixing of the crucible components can be prevented by using a high heat resistant crucible.

<Others>
It is desirable that the processing tanks 11a to 11c, the drying chamber 21, and the scrubber tank 41 are all capable of being sealed (liquid-tight or air-tight), and the entire processing systems 1 and 2 can be shut off from the external atmosphere. The treatment tanks 11a to 11c, the drying chamber 21, the scrubber tank 41, the drain pipe and the like are not particularly limited, but it is desirable to use a material having high corrosion resistance and wear resistance such as stainless steel. However, when pH adjustment is performed in the pretreatment of the waste liquid D, alkali- and acid-resistant materials are not necessary. Devices such as a temperature control device, a pressure control device, and a contaminant detection device (radiation dosimeter) can be connected to the processing device 10, the spray drying device 20, and the scrubber 40, and these devices are controlled by a control device (computer). It is also possible to connect to a switching operation such as switching of a valve (valve). Further, the switching of the valve is not limited to machine control, and may be manually performed by a human with reference to the measurement result of the detection device.

  In addition, one or more open / close valves, orifices, back pressure valves, pressure keeping valves, constant flow valves, pressure reducing valves, flow meters, pressure gauges, etc. are provided in the pipes connecting the devices such as drain pipes, connecting pipes and exhaust pipes. Connection switching and flow rate adjustment can also be performed. When there is a possibility that the amount of waste liquid D supplied from the waste liquid source 19 may exceed the processing capacity of the processing systems 1 and 2, a cushion tank or the like may be provided between the processing systems 1 and 2 and the waste liquid source 19. Moreover, processing tank 11a-11c can also be used as a cushion tank.

  The type of the treatment liquid L is not particularly limited, and various types such as an organic solvent and a buffer solution can be used, but water (tap water) is preferable from the viewpoint of safety. When the treatment liquid L is water, if the contaminated treatment liquid L is treated as waste liquid D to remove the contaminants, the waste liquid D (treatment liquid L) in the apparatus is the standard for sewage in both systems 1 and 2. It will be filled and can be discarded as sewage. In addition, in order to improve the supplement (dispersion) property of dust, additives such as a pH adjuster, a buffering agent, and a surfactant can be added to the treatment liquid L.

  The connection of the drain pipes 46 and 47 is not particularly limited, but in any of the processing systems 1 and 2 of the first example and the second example, the processing tank 11b to which an additive (particularly a pH adjusting agent) is added or the processing tank It is desirable to connect to the treatment tank 11a closer to the waste liquid source 19 than 11b. In this case, since the contaminated processing liquid L is pretreated (for example, pH adjustment) by the processing apparatus 10 and then sent to the spray drying apparatus 20, the contaminated processing liquid L is not supplied to the spray drying apparatus 20 and the apparatus is corroded. Is prevented.

The heating means 32 of the spray drying apparatus 20 and the processing apparatus 10 (processing tanks 11a to 11c) is not particularly limited, and various types such as a heating wire, a hot air fan, and a combustion furnace can be used. When the installation location is a factory or the like, it is preferable from the viewpoint of cost and environment to use the exhaust heat generated from the factory equipment using a boiler heat exchanger or the like. Since the processing system 1 of the present invention is small in size and can freely change the number of units 1 ′, 1 ₁ , 1 and ₂ by connection, it can be easily installed in combination with existing factory equipment.

  The separating agent used in the present invention is not particularly limited as long as it is a substance that reduces the solubility (dispersibility) of the target substance. Any one or more of an agent, a coprecipitate, and an adsorbent are desirably used. For example, the sulfiding agent reacts with metal ions in the waste liquid to produce a hardly soluble sulfide, and the alkali reacts with metal ions to form a hardly soluble metal hydroxide. It is particularly desirable to use a pH adjuster in combination for reducing the corrosivity and improving the cohesiveness of the solid content. The flocculant, the coagulant aid, and the coprecipitation agent are those that coagulate (coprecipitate) the target substance and separate it as a solid content, and it is desirable to use it together with a sulfurizing agent or an alkali.

  Although the adsorbent is not particularly limited, for example, a porous material such as zeolite, silica, alumina gel, clay, activated carbon or the like can be used, and the target substance D in the waste liquid is adsorbed by the adsorbent, and the solid content (the target substance is adsorbed). Separated from the waste liquid D. When the target substance is present in the waste liquid D as ions, the use efficiency of the target substance is increased by using an ion-adsorbing porous substance (cationic substance, anionic substance).

  However, when the amount of solid content is large and the spray nozzle 22 may be clogged, the use of a separating agent is unnecessary. When it is necessary to use a separating agent for recovering the target component, it is desirable to prevent clogging of the spray nozzle 22 by, for example, dispersion processing by the stirring means 18, dilution with a diluent, use of a dispersing agent, or the like. .

In the connection processing system 2 of the second example, the type of the separating agent (adsorbent) as described above can be changed for each of the units 1 ′, 1 ₁ , and 1 ₂ . For example, the upstream side of the unit 1 'in inexpensive large amounts of adsorbent material capable of adsorbing (zeolites, activated carbon, etc.) using a high adsorption capacity downstream unit 1 ₂ in expensive close to the discharge pipe 49 (Prussian blue, etc.) For example, a separating agent (adsorbent) can be properly used. Further, when the contamination level of the waste liquid D or the vapor is high, an adsorption filter or the like is provided in the pipe (the connecting pipe 51, the discharge pipe 49, the drain pipe 46, 47, etc.), the scrubber 40, the processing apparatus 10, etc. Adsorption and adsorption by an adsorption filter can be used in combination.

  DESCRIPTION OF SYMBOLS 1 ... Processing system (1st example), 2 ... Connection circulation processing system (2nd example), 10 ... Processing apparatus, 13 ... Addition means, 20 ... Spray drying apparatus, 32 ... Heating means, 36 …… Control device, 35 …… Processing liquid source, 40 …… Scrubber, 41 …… Scrubber tank, 42 …… Shower nozzle, 43 …… Livestock solution part, 45 …… Control means, D …… Waste liquid, L …… Treatment liquid

Claims (10)

A waste liquid connected circulation processing system having a plurality of processing systems,
Each processing system is supplied with a waste liquid to be processed, and performs a pretreatment of the waste liquid;
An adding means connected to the processing apparatus for adding an additive for pretreatment;
A spray-drying device connected to the treatment device and spray-drying the waste liquid after pretreatment to remove solids as powder;
Each having a scrubber connected to the spray drying device to perform dust treatment,
The scrubber has a scrubber tank connected to the spray drying device, and a shower nozzle that ejects a treatment liquid into the scrubber tank,
The scrubber tank is formed with a livestock part for stocking the treatment liquid,
The shower nozzle is connected to both the treatment liquid source and the livestock solution section,
In the connected circulation processing system in which either or both of the clean processing liquid supplied from the processing liquid source and the used processing liquid supplied from the livestock liquid section are ejected from the shower nozzle,
Among the plurality of processing systems, a processing system in which a processing apparatus is directly connected to a waste liquid source is an upstream unit,
Each of the n processing units other than the upstream unit (n is an arbitrary integer) is a downstream unit, and each processing device of the n downstream units is directly connected to the scrubber of the upstream unit or via another downstream unit. Connected,
Another processing system that can be connected to the nth downstream unit from the upstream unit is a spare unit,
The n-number-th of the downstream units of the scrubber is provided contaminant detection device, wherein when the detected level of contamination in the contaminant detector is higher than the reference value, the connection scrubber downstream units of the n-number-th is the protection unit Connected circulation processing system.
The said liquid storage part of each processing system is connected to the said processing apparatus of the same processing system, and the said processing liquid after dust processing is sent without flowing backward from the said livestock part to the said processing apparatus. Concatenated circulation processing system. The scrubber tank of each processing system is provided with a control means,
The connected circulation processing system according to any one of claims 1 and 2, wherein the control means increases or decreases a supply amount from the processing liquid source to maintain a constant amount of the stock solution in the stock solution section. A waste liquid treatment method for performing waste liquid treatment using the connected circulation treatment system according to any one of claims 1 to 3,
In each treatment system, the waste liquid is pretreated by the treatment apparatus without flowing into the scrubber, and the waste liquid after pretreatment is spray dried by the spray drying apparatus. In at least in one processing system, when the treatment liquid of the畜液portion is contaminated, the contaminated treatment fluid transferred to the processor in the same processing system from the畜液unit as waste, the The waste liquid treatment method according to claim 4, wherein spray drying is performed after the treatment by the treatment apparatus. 6. The waste liquid treatment method according to claim 4 , wherein in at least one treatment system, the pH of the waste liquid is made close to neutral and then sent from the treatment apparatus to the spray drying apparatus. 7. 8. The powder according to claim 5 , wherein in at least one processing system , spray drying is performed in a state in which a temperature of the spray drying apparatus is maintained at 127 ° C. or higher to create the solid powder. Waste liquid treatment method. After recovering the powder from the spray-drying device, a waste liquid treatment method for performing a post-treatment of heating at a preset firing temperature,
The upper limit of the firing temperature does not exceed the melting point of the recovery target component,
The waste liquid treatment method according to claim 7 , wherein the lower limit of the firing temperature is any one of a melting point of the impurity, a boiling point of the impurity, a decomposition temperature of the impurity, and a combustion temperature of the impurity. It is a waste liquid processing method which performs waste liquid processing using the connection circulation processing system of any one of Claims 1-3, Comprising: Radioactive contamination water is processed as said waste liquid , and adsorption of a radioactive substance as said additive Waste liquid treatment method using chemicals . The number n of the downstream systems is 2 or more,
In the first downstream system in which the processing apparatus is directly connected to the scrubber of the upstream system, zeolite and / or activated carbon is used as the additive,
The waste liquid treatment method according to claim 9, wherein Prussian blue is used as the additive in a downstream system in which a treatment apparatus is connected to the upstream system via another downstream system after the first unit.