JP2013221765A - Inorganic coagulant for removing radioactive substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide inorganic coagulant to be used for radioactive substance removing treatment by separating recovery waste fluid of high-pressure water absorption cleaning into secondary flocks and clean water so that the clean water can be wasted to a public water system.SOLUTION: An inorganic coagulant for separating recovery waste liquid to primary flocks and secondary flocks by cationic coagulant and anionic coagulant is prepared for radioactive substance removal by blending aluminum sulfate for converting fine particles into primary flocks and capturing the primary flocks, calcium carbonate having precipitation acceleration action of the secondary flocks and PS ash or the like for capturing extremely fine particles and/or ionic radioactive cesium to be a radioactive substance with the inorganic coagulant. Although 98% or more of radioactive substance removing capacity is shown, radioactive substances can be removed to be less than a detection limit by regulating the added content of the PS ash, and further the water content of secondary flocks can be reduced by additionally using a water-curing substance. Thus the inorganic coagulant can be suitably used for high-pressure absorption water cleaning in a radiation contaminated area.

Description

  The present invention relates to an inorganic flocculant for removing a radioactive substance used for removing a radioactive substance by using it in a recovery waste liquid of high-pressure water-absorbing washing.

  As this type of inorganic flocculant, one of the applicants used the waste liquid containing cement, clay, etc. at the construction or civil engineering sites to separate clean water and secondary flocs, and to dispose of clean water on site. Accordingly, a secondary floc that can be reused as a cement mixture has been proposed. According to this, a cationic polymer flocculant for forming a primary floc, a nonionic system for forming a secondary floc, and Mixing and containing anionic polymer flocculant and inorganic fine powder for sedimentation weight of the secondary floc to separate the recovered waste liquid into secondary floc containing clean water that can be drained on site and cement, clay, etc. It is supposed to be a free inorganic flocculant.

JP 2008-55342 A

  In this case, separation of clean water and secondary flocs is carried out on site in a vehicle with secondary flocs reduced in volume as much as possible by simply and surely treating them on site in a very short time and disposing of clean water on-site. By taking it home, it has been highly evaluated as an inorganic flocculant for on-site treatment, which can reduce the burden on the contractor as much as possible.

  On the other hand, due to the diffusion of radioactive materials such as iodine 131, cesium 137, and cesium 134 resulting from the damage of the nuclear power plant caused by the Great East Japan Earthquake, radioactive materials, particularly food, There is a strong demand for rapid and accurate removal of radioactive cesium that causes contamination of water and internal exposure of the human body. When removing or cleaning the radioactive material, roads, schoolyards, rooftops, Non-water-absorbing surfaces such as concrete such as roofs, water-absorbing surfaces such as surface soil, and water treatment such as contaminated water that has been moved down the public waterway, for example, high pressure washing, high pressure water washing, brushing after water washing, polishing In the latter case, various removal or cleaning methods such as surface soil cleaning and contaminated water storage cleaning can be considered. While it is assumed that rapid and efficient treatment is possible if it can be used, according to Patent Document 1, the waste liquid generated accompanying the removal process or the washing process is recovered, from the recovered waste liquid, If the secondary flocs of dust containing sand and mud are separated and radioactive substances other than those envisaged in Patent Document 1 can be removed together with the secondary flocs, washing water can be used for the radioactive substance removal treatment or washing treatment. If the recovered waste liquid generated by use can be purified, the volume of the secondary floc that can be discarded in the public waterway without diffusing the radioactive material and containing the radioactive material is reduced as much as possible. It becomes possible to carry-in processing to a designated disposal place as state designated waste, and to cooperate with the treatment of a designated administrative place with a limited amount of carry-in.

  The present invention has been made in view of such circumstances, and the problem to be solved is that the radioactive substance can be removed or washed as much as possible by allowing the radioactive substance to remain in the secondary floc effectively and appropriately. An object of the present invention is to provide an inorganic flocculant for removing radioactive substances that can be realized with high efficiency.

  As a result of diligent examination along the above-mentioned problems, the dust, such as sand and mud, on the non-water-absorbing surface that is subject to radioactive substance removal treatment includes fine particles, so that the fine particles are primary flocked and captured. In doing so, it is effective to contain aluminum sulfate (which may be called a sulfate band), and most of the radioactive substances, particularly radioactive cesium, adhere to the dust, but adhere to the fine particles, There are a few ionic radioactive substances, and these tend to be difficult to trap even with the above-mentioned aluminum sulfate. Therefore, these ultrafine particles and ionic radioactive substances Paying attention to the fact that it is effective to contain a porous material for accurately and surely capturing, by mixing and containing these aluminum sulfate and porous material, An inorganic flocculant suitable for removal of radioactive materials used in the removal treatment or cleaning treatment of radioactive substances. That is, the invention according to claim 1 is used to remove or wash radioactive substances. A powder-type flocculant having a radioactive substance removal function for removing radioactive substances contained in the waste liquid, a cationic polymer flocculant for primary floc formation, aluminum sulfate for promoting floc formation of fine particles, A nonionic and / or anionic polymer flocculant for forming secondary flocs, an inorganic fine powder for sedimentation weight of the secondary flocs, and a porous material for adsorbing ultrafine particles or ionic radioactive substances Radiation characterized by mixing and containing, allowing the recovered waste liquid to be segregated into clean water that can be drained on-site and secondary flocs containing aggregated sediment containing radioactive materials for storage in place. It is obtained by a material removal inorganic aggregating agents.

  In addition to the above, the invention according to claim 2 can perform the removal of the radioactive substance as easily and as efficiently as possible by using the waste liquid of the removal process or cleaning process of the radioactive substance as a waste liquid by high-pressure water-absorbing cleaning. 2. The radioactive substance removal according to claim 1, wherein the waste liquid of the radioactive substance removal treatment or washing process is used as a waste liquid of high-pressure water-absorbing washing using a high-pressure water-absorbing washing machine. Inorganic flocculants.

  In addition to the above, the invention according to claim 3 is characterized in that the porous material used for capturing the ultrafine particles and the ionized radioactive material is PS ash formed by baking paper sludge. In addition to being effective in trapping radioactive materials, the PS ash is bulky, so that it is interposed between the secondary flocs to prevent the secondary flocs from becoming excessively large and accelerate their sedimentation to increase the sedimentation speed. Since it is effective, the porous material for adsorbing the radioactive material is used as PS ash obtained by baking paper sludge so that the fine fine particles or the ionic radioactive material in the recovered waste liquid can be adsorbed freely. The inorganic flocculant for removing a radioactive substance according to claim 1 or 2, characterized in that it is characterized in that.

  In addition to the above, when the porous material is PS ash, the mixed content of the invention described in claim 4 is preferably 5 to 60 wt% of the flocculant. It is preferable to effectively supplement ionic radioactive substances and prevent secondary flocs from becoming excessive, so that the PS ash is 5 to 60 wt%. The inorganic flocculant for removing a radioactive substance described in 1. is used.

  In addition to the above, the invention according to claim 5 further accelerates the sedimentation by the inorganic fine powder for the sedimentation weight of the secondary floc as much as possible to complete the sedimentation of the secondary floc in a short time. It is effective to contain an insoluble inorganic substance having a specific gravity of 2 to 3 obtained by pulverizing silica sand or silica stone, limestone, wax stone, serpentinite, etc., and this is used as a sedimentation accelerator for the inorganic fine powder. The inorganic flocculant for removing a radioactive substance according to claim 1, 2, 3 or 4, characterized by further containing an insoluble inorganic substance.

  In addition to the above, the invention described in claim 6 is the settling of the remaining primary floc remaining in the recovered waste liquid of secondary floc formation leakage due to the nonionic and / or anionic polymer flocculant for forming the secondary floc. It is effective to contain slaked lime in order to complete the settling of the remaining primary floc together with the secondary floc in as short a time as possible. 6. The slaked lime is additionally contained as a settling accelerator for the remaining primary floc in the secondary floc formation leakage due to the anionic polymer flocculant. This is an inorganic flocculant for removing radioactive substances.

In addition to the above, the invention according to claim 7 is a suspended water containing agglomerated precipitates in which the secondary floc separated from clean water contains a considerable amount of water. Since there is a possibility that moisture leaks from the gap between the two, it becomes a factor that hinders workability in on-site work such as transportation. Therefore, ettringite (3CaO · Al ₂ O _3. 3SO 4 · _32H and water retention as 2 _O) crystal water in, so by the secondary floc and solidified shaped aggregate precipitates with Pasatsuki feeling, can make easier the handling such as transportation in the field In order to ensure good workability of the field work, the cationic polymer flocculant, aluminum sulfate, nonionic and / or anionic polymer flocculant, In addition to the mechanical fine powder and the porous material, the water content in the secondary floc of the aggregated precipitate-containing suspension water is retained as crystallization water in ettringite, and the secondary floc is used as a solidified aggregated precipitate. The inorganic flocculant for removing a radioactive substance according to claim 1, 2, 3, 4, 5 or 6, further comprising a substance.

  In the invention according to claim 8, in addition to the above, a hydraulic substance having the secondary floc as a solidified aggregated precipitate is not added to the flocculant, and is added later to the secondary floc. Therefore, the secondary floc can be used as the same coagulated sediment to ensure good workability in the field work, so that the hydraulic substance can be cleaned instead of containing the hydraulic substance. The inorganic flocculant for removing a radioactive substance according to claim 7, wherein the inorganic flocculant is added for post-packaging addition to the secondary floc after separation of water and secondary floc.

  The present invention uses each of these as the gist of the invention as means for solving the above problems.

  Since the present invention is configured as described above, the invention described in claim 1 includes dusts such as sand, mud and the like on the non-water-absorbing surface to be subjected to the radioactive substance removal treatment, including fine particles. In order to make the fine particles primary floc, aluminum sulfate is contained, and the fine particles adhering to the fine particles, which are slightly present, are porous materials for capturing ionic radioactive materials, particularly radioactive cesium. Focusing on the fact that it is effective to contain, by containing these aluminum sulfate and a porous material in mixture, an inorganic flocculant suitable for removal of the radioactive material used in the removal treatment or cleaning treatment of the radioactive material. Can be provided.

  In addition to the above, the invention according to claim 2 can perform the removal of the radioactive substance as easily and as efficiently as possible by using the waste liquid of the removal process or cleaning process of the radioactive substance as a waste liquid by high-pressure water-absorbing cleaning. Can be.

  In addition to the above, the invention described in claim 3 is characterized in that, in addition to the above, the porous material used for capturing the ultrafine particles and the ionic radioactive material is PS ash formed by baking paper sludge. Effectively captures ultrafine particles and ionic radioactive materials, and intersperses the PS ash between the secondary flocs to prevent the secondary flocs from becoming excessive and promote their sedimentation to increase the sedimentation rate. can do.

  In addition to the above, when the porous material is PS ash, the mixed content of the invention described in claim 4 is 5-60 wt% of the flocculant, so that the ultrafine particles In addition, it is possible to effectively supplement the ionized radioactive material and to prevent the secondary floc from becoming excessive.

  In addition to the above, the invention according to claim 5 has a specific gravity of 2 to 3 in which the sedimentation by the inorganic fine powder for the sedimentation weight of the secondary floc is pulverized from quartz sand, quartzite, limestone, wax stone, serpentinite, etc. The insoluble inorganic substance can be promoted as much as possible, and the secondary flocs can be settled in a short time.

  In addition to the above, the invention described in claim 6 is characterized in that the remaining primary floc remaining in the recovered waste liquid of secondary floc formation leakage due to the nonionic and / or anionic polymer flocculant for forming the secondary floc is By containing slaked lime, the sedimentation can be promoted, and the sedimentation of the remaining primary floc can be completed in the shortest possible time together with the secondary floc.

The invention according to claim 7, also in addition to the above, ettringite the water clean water and separate the secondary flocs were produced by the hydration reaction _{(3CaO · Al 2 O 3 ·} 3SO 4 · 32H 2 O) By absorbing water as crystal water and making the secondary floc a solidified coagulated sediment with a feeling of roughness, it is easy to handle on-site transportation etc. Workability can be ensured.

  In the invention according to claim 8, in addition to the above, a hydraulic substance having the secondary floc as a solidified aggregated precipitate is not added to the flocculant, and is added later to the secondary floc. As a result, the secondary floc can be used as the same coagulated sediment to ensure good workability in field work.

It is a model figure which shows the state of the washing process by a high pressure water absorption washing | cleaning. It is an expanded sectional view of the spinner part of FIG.

  Hereinafter, the present invention will be described in more detail. A in the drawing is a high-pressure water-absorbing washing machine for removing radioactive substances, for example, which can be used as a method for removing or washing radioactive substances. The high-pressure water-absorbing and cleaning machine A includes a high-temperature and high-pressure suction device 1, a cleaning spinner 2 that supplies high-pressure hot water by connecting a hose to the high-temperature and high-pressure suction device 1, the cleaning spinner 2, and the high-temperature and high-pressure suction device. A hose is connected to the apparatus 1 to recover cleaning waste gas from the cleaning spinner 2 and to the waste gas waste liquid separation apparatus 3 for recovering waste gas to the high-temperature and high-pressure suction apparatus 1, and to the waste gas waste liquid separation apparatus 3. And a waste liquid treatment tank 4 for collecting the waste liquid.

  The radioactive substance cleaning process by the high-pressure suction washer A is performed by, for example, connecting the water supply 11 to the high-temperature high-pressure suction device 1 to supply cleaning water and cleaning the high-temperature cleaning water heated by the high-temperature high-pressure suction device 1. High-temperature cleaning using the cleaning from the suction hole 22 disposed on the inner peripheral edge of the cleaning spinner 2 while high-pressure jetting is performed on the cleaning target site of the radioactive substance cleaning target through the rotating nozzle 21 of the spinner 2 The water is sucked and recovered and returned to the waste gas waste liquid separation device 1, and the waste gas separated by the waste gas waste liquid separation device 3 is again sucked into the high temperature and high pressure suction device 1, while the waste liquid separated by the waste gas waste liquid separation device 3. Is collected in the waste liquid treatment tank 4 and the waste liquid collected in the waste liquid treatment tank 4 is purified by introducing and aggregating the radioactive aggregate-removing inorganic agglomerated material into the waste liquid treatment tank 4. Discharge to public water system On the other hand, this is performed so that the secondary flocs, which will be described later, which are the remaining agglomerated sediment-containing suspension water separated by the inorganic flocculant, are separately carried into a designated disposal place as designated waste. .

  At this time, the inorganic flocculant for removing radioactive substances is a cationic flocculant for forming primary flocs as a powder flocculant having a radioactive substance removing function for removing radioactive substances contained in the recovered waste liquid of high-pressure water-absorbing washing. A flocculant, aluminum sulfate for promoting floc formation of fine particles, nonionic and / or anionic polymer flocculants for forming secondary flocs, and inorganic fine powder for sedimentation weight of the secondary flocs; Secondary flocs containing aggregated sediment-containing suspended water containing ultrafine fine particles or porous materials for adsorption of ionic radioactive materials, and containing recovered wastewater containing clean water that can be drained on-site and radioactive materials that are stored in place In the present example, the porous substance for adsorbing the radioactive substance includes the cationic polymer flocculant, aluminum sulfate, nonionic and / or In addition to the anionic polymer flocculant, the inorganic fine powder and the porous substance, an insoluble inorganic substance having a specific gravity of 2 to 3 as a sedimentation accelerator for the inorganic fine powder is used as a nonionic for forming the secondary floc and / or It contains slaked lime as a settling accelerator for residual primary flocs due to secondary floc leakage due to anionic polymer flocculants, and also retains the water in the secondary flocs of the above aggregated sediment-containing suspension water as crystal water in ettringite. Thus, a hydraulic substance that makes the secondary floc a solidified aggregated precipitate is additionally contained.

  The cationic polymer flocculant is added to mix dust containing sand, mud, etc. from the collected waste liquid in combination with dust to which radioactive substances are attached, and is mixed and contained. The flocculant dissolves in the recovered waste liquid by adding a small amount of the powder, and neutralizes dust such as sand and mud by reacting with negative charge of dust such as sand and mud in the waste liquid. It is intended to be used for primary flocking by promoting the attractive action between dust and condensing each other.

  The cationic polymer flocculant is added and contained in an amount of 0.07 to 0.8 wt% with respect to the weight of the inorganic flocculant for removing radioactive substances. While the capacity is insufficient and primary flocs cannot be formed, the excess cationic polymer flocculant that does not contribute to the formation of primary flocs remains in the waste liquid when it exceeds 0.8 wt%. As a result of an increase in the biochemical oxygen demand (BOD), it becomes unsuitable as clean water to be discharged to the public water system after treatment of the recovered waste liquid. At this time, if the amount is less than 0.15 wt%, the tendency to decrease the formation of primary flocs tends to be reduced, whereas if the amount exceeds 0.4 wt%, a tendency to increase BOD due to the cationic polymer flocculent tends to be caused. The cationic polymer flocculant is preferably 0.15 to 0.4 wt% from the viewpoint of both primary floc formation and environmental maintenance.

  Aluminum sulfate is added and mixed to promote the formation of flocs of fine particles by the cationic polymer flocculant. By adding the aluminum sulfate, fine particles of dust such as sand and mud are added. The primary floc formation is greatly promoted, the radioactive substances in the recovered waste liquid are reduced as quickly as possible, and the recovered waste liquid in the radioactivity removal operation can be efficiently processed in a short time.

  Aluminum sulfate is added and contained in an amount of 5 to 20 wt% with respect to the weight of the inorganic flocculant for removing radioactive substances. When the amount is less than 5 wt%, the amount is insufficient and the effect of promoting the formation of primary flocs is obtained. When it exceeds 20 wt, it becomes excessive in quantity, and the primary flock formation promoting effect is not changed, leading to waste and meaninglessness. In addition, if the amount is less than 7 wt%, the amount tends to be insufficient, and if the amount is more than 12 wt%, the primary floc formation promoting effect tends to be an upper limit. From the viewpoint of effectively securing the effect, it is preferable to set this to 7 to 12 wt%.

  The nonionic and / or anionic polymer flocculant, in this example, the anionic polymer flocculant is formed by neutralizing and coagulating the cationic flocculant, and using the above cationic polymer flocculant or this and aluminum sulfate. The primary floc of the recovered waste liquid is re-aggregated and coarsened by a cross-linking adhesive action, and the primary floc is converted into a secondary floc.

  The nonionic and / or anionic polymer flocculant is added in an amount of 0.05 to 0.8 wt% with respect to the weight of the radioactive flocculant inorganic flocculant, and 0.05 wt% If it is below, it will be insufficient in quantity and it will be difficult to demonstrate the cross-linking adhesive action and secondary floc forming ability, and if it exceeds 0.8 wt%, it will be excessive in quantity and there will be a change in secondary floc forming ability. The polymer flocculant is wasted without being seen. In addition, if it is less than 0.15 wt% at this time, the cross-linking adhesive action is lowered, and the tendency to lower the secondary floc-forming ability tends to be reduced, and if it exceeds 0.8 wt%, the primary floc-forming ability tends to be the upper limit. Since it becomes easy to invite, it is preferable that this nonionic and / or anionic polymer flocculant is 0.15 to 0.8 wt% from the viewpoint of effectively ensuring the ability to form secondary flocs.

  The inorganic fine powder is used as the sedimentation weight of the secondary floc, and is taken into the secondary floc to promote the sedimentation of the secondary floc and treat the recovered waste liquid in as short a time as possible. . The inorganic fine powder uses, for example, calcium carbonate having a specific gravity of about 2.0 to 3.0 and a particle size of 325 to 500 mesh (may be called tancal). At this time, the inorganic fine powder has a specific gravity that is too small when the specific gravity is less than 2.0, and the effect of promoting the sedimentation of the secondary flocs tends to be inferior. The specific gravity is preferably in the range of 2.0 to 3.0 because it tends to settle by itself before being taken into the next floc, and the smaller the particle size, the easier it is taken into the secondary floc. Since a sedimentation promoting effect can be expected, the above-described 325 mesh to 500 mesh is preferable.

  The inorganic fine powder is added and contained in an amount of 40 to 70 wt% with respect to the weight of the inorganic flocculant for removing radioactive substances. When the inorganic fine powder is less than 40 wt%, it is quantitatively used as a sedimentation weight of the secondary floc. If it is insufficient and exceeds 70 wt%, it will be excessive in quantity and will be settled alone without being taken into the secondary flocs. Further, if it is less than 50 wt%, it tends to be quantitatively insufficient as a sedimentation weight, and if it exceeds 65 wt%, it tends to be excessive in quantity. Therefore, the inorganic fine powder is reduced to 50 to 65 wt%. % Is preferable.

  The porous substance is added and used so as to adsorb and remove ultrafine particles or ionic radioactive substances in the recovered waste liquid. Since the radioactive substance in the radioactive substance cleaning target adheres to dust, such as sand and mud scattered in the target part, in addition to the target part to be cleaned, it is simultaneously removed by the temporary flocking or the secondary flocking of the recovered waste liquid. However, when the recovered waste liquid contains finer fine particles and ionic radioactive substances other than those attached to them, these fine fine particles and ionic radioactive substances are separated from the primary flocs or second. Because it is too small to capture as the next floc, it is easy to result in that it cannot be sufficiently captured. For this reason, radioactive materials and ions attached to these ultrafine particles that remain in the recovered waste liquid by adding and using porous materials Adsorption and removal of the radioactive radioactive material is performed.

  At this time, the porous substance has an adsorbing ability for radioactive substances and ions thereof, for example, zeolite, brussian blue, PS ash and the like having a large porosity and an effective adsorbing ability. When ash is used, for example, a bulk specific gravity of 0.6, a porosity of 75%, a central pore diameter of 3.8 μm, and a pH of about 10 can be used. PS ash has an excellent ability to adsorb radioactive substances and has a bulk specific gravity of Since it is large and bulky, by adding and using the PS ash, the fine fine particles and the ionic radioactive substance are effectively and accurately adsorbed and removed, and a secondary flock is interposed between the secondary flocks when forming the secondary flock. By preventing the flocs from adhering to each other, it is possible to avoid the secondary flocs from adhering to each other and causing complicated processing.

  Porous substances, especially PS ash, is added and contained in an amount of 5 to 60 wt% with respect to the weight of the inorganic flocculant for removing radioactive substances. If it is less than 5 wt%, PS ash is insufficient in quantity. As a result, the adsorption and removal of ultrafine particles and ionic radioactive materials, especially radioactive cesium, becomes insufficient, and the remaining of radioactive cesium is observed in clean water separated from the recovered waste liquid. When the amount is excessive, fine particles of PS ash slightly remain on the surface of the clean water after the coagulation treatment, and radioactive cesium remains in the clean water after separation. If it is less than 15 wt% and more than 40 wt% to less than 40 wt%, there is a tendency that a slight amount of radioactive cesium remains, so that the PS ash may be made 15 to 40 wt% to less than 40 wt%. Preferably, when the PS ash exceeds 35 to 36 wt%, the clean water separated from the recovered waste liquid tends to be colored light brown (it seems to be due to iron oxide). It is particularly preferable to set it to 36 wt%.

  In this example, the insoluble inorganic substance having a specific gravity of 2 to 3 additionally added may be, for example, crushed silica sand, silica stone, limestone, wax stone, serpentinite, etc. In this example, as a calcium carbonate precipitation accelerator, it is used in combination with an inorganic fine powder so as to accelerate its sedimentation rate. For example, when silica sand is used as the insoluble inorganic substance, the silica sand has a specific gravity of 2.6, an average particle size of 0.3 to 0.25 mm, and a particle size of 0.6 to 0.07 mm to 0.4 to 0.05 mm. Those having a distribution (for example, silica sand No. 6, No. 6 A, etc.) are preferable. The silica sand is added and contained in an amount of 5 to 20 wt% with respect to the weight of the inorganic flocculant for removing the radioactive substance. It becomes difficult to ensure the effect, and if it exceeds 20 wt%, it becomes excessive in quantity and tends to settle separately. Therefore, the silica sand is preferably 5 to 20 wt%.

  The slaked lime which is additionally added in this example is also used as a settling accelerator for the remaining primary floc of secondary floc leakage due to the nonionic and / or anionic polymer flocculant for forming the secondary floc. The slaked lime is added and contained in an amount of 5 to 15 wt% based on the weight of the inorganic flocculant for radioactive substance removal, and if it falls below 5 wt%, the amount of residual primary floc is insufficient. It becomes difficult to ensure the sedimentation promoting effect, and when it exceeds 15 wt%, the amount becomes excessive and sedimentation occurs. Moreover, if it is less than 8 wt% at this time, it tends to reduce the sedimentation promoting effect of the remaining primary flocs, and if it exceeds 12 wt%, the slaked lime tends to settle independently, so the slaked lime is 8 to 12 wt%. Is preferred.

  Table 1 shows the above-mentioned inorganic flocculant for removing a radioactive substance as a list of the powdery raw material, the quantitative range in the flocculant, and the weight percent of the preferred quantitative range.

The inorganic flocculant for removing radioactive substances may be formed by the above composition, but in addition to the composition, the hydraulic substance can be additionally used. water in the secondary flocs of objects containing aqueous suspension with water held as crystal water in ettringite produced by the hydration reaction _{(3CaO · Al 2 O 3 ·} 3SO 4 · 32H 2 O), solidified form a secondary floc Thus, for example, it is possible to easily handle the secondary flock on the spot as a cohesive precipitate with a feeling of water that does not flow out of water even under a certain degree of squeezing and pressurization. If the hydraulic substance forms ettringite, for example, gypsum, calcium aluminate, cement, lime or the like alone or a mixture of two or more thereof can be used. The hydraulic material may be added and contained in addition to the above composition, and the addition amount may be determined in light of the state of securing the hydraulic property by the hydration reaction of the secondary floc. On the other hand, the hydraulic substance additionally used for the inorganic flocculant is replaced with the secondary flocs after separation of clean water and secondary flocs, instead of containing it in the inorganic flocculant for removing radioactive substances. It is possible to prepare for post-packaging addition to be added to the floc. The post-addition is separately packaged from the above-mentioned inorganic flocculant for removing radioactive substances, and this is referred to as the flocculant. What is necessary is just to supply separately.

  The inorganic flocculant for removing radioactive substances configured as described above is used by mixing and using the recovered waste liquid washed by the high-pressure (wet) washer to effectively and appropriately contain the radioactive substance in the secondary floc. In addition, it is possible to efficiently remove radioactive substances in a short time, including capture of ultrafine particles present in the recovered waste liquid, including ionic radioactive substances, particularly radioactive cesium, In particular, it is possible to separate the recovered waste liquid into secondary flocks of specified waste containing radioactive substances and clean water for removing radioactive substances that do not contain radioactive substances, and then dispose of the clean water into public sewage at the cleaning site. it can. In addition, by using a hydraulic substance, water in the secondary floc is absorbed and retained as crystal water in the ettringite produced by the hydration reaction, and the secondary floc is formed as a solidified aggregated precipitate with a soft feeling. It is possible to easily handle on-site transportation, etc., and to ensure good workability in on-site work, and to easily and quickly carry out radioactive substance removal work using the high pressure washer. be able to.

  Although the illustrated example is as described above, in addition to the radioactive substance removal work using the high-pressure feed water washer, the radioactive substance removal treatment or washing treatment is performed on a non-water-absorbing surface or a water-absorbing surface, and consequently In water treatment such as contaminated water storage that has flowed down the public waterway, this can be done by various removal or washing methods such as high pressure washing, brushing after water washing, polishing, grinding, surface soil washing, washing treatment of contaminated water, etc. In addition, it is possible to perform the removal of radioactive substances as efficiently as possible by treating the waste liquid effectively and appropriately by widely using the above-mentioned inorganic coagulant for removing radioactive substances in the waste liquid as well. Can do.

Experimental example

  No. 1 to No. The inorganic flocculant of No. 5 was composed, stirred into the radioactively contaminated water, stirred, and the radioactive substance removing ability was measured and determined using the supernatant liquid separated from the secondary floc as test water.

  As shown in Table 2, the inorganic flocculants are as follows: cationic flocculant 0.27 wt%, anionic flocculant 0.27 wt%, calcium sulfate 7.16 wt%, slaked lime 2.7 wt%, quartz sand (No. 6) 13 .5 wt% in common and the remaining 76.1 wt%, the addition contents of the porous material (PS ash) and the inorganic fine powder (calcium carbonate) were respectively changed. 1, porous material (PS ash) 0.0 wt%, inorganic fine powder (calcium carbonate) 76.1 wt%, No. 1 2 is 17.9 wt% of porous material (PS ash), 58.2 wt% of inorganic fine powder (calcium carbonate), No. 2 3 is 40.0 wt% porous material (PS ash), 36.1 wt% inorganic fine powder (calcium carbonate), No. 3 4 is 60.0 wt% porous material (PS ash), 16.1 wt% inorganic fine powder (calcium carbonate), No. 4 5 was 76.1 wt% of a porous material (PS ash) and 0.0 wt% of an inorganic fine powder (calcium carbonate).

  As shown in Table 3, the test water is No. for each raw water amount of about 750 g. 1 to No. No. 5 inorganic flocculant, no. 1 for 8.2 g, No. 1 14.6 g, No. 2 No. 3, 20.8 g, no. 4 for 27.7 g, no. 29.9 g of No. 5 was added and stirred, allowed to stand overnight, and each about 500 g of supernatant was collected and used as test water. For comparison, raw water was used as test water.

  About each test water, it detects radioactive iodine (I-131) and radioactive cesium (Cs-137, Cs-134, Cs-136) using a germanium semiconductor detector, and removes the radioactive substance from the inorganic flocculant. The ability was judged. The results are shown in Table 4 (excluding Cs-136).

  Furthermore, for raw water containing high concentration of radioactive cesium, The radioactive substance removing ability was measured with test water using the inorganic flocculant of No. 2. The results are shown in Table 5. In addition, for each test water, the hydrogen ion index (pH) by the glass electrode method of JISK010212.1, the biochemical oxygen demand (BOD) by the diaphragm electrode method of JISK010221 and JISK010232.3, and the Environment Agency Notification No. 59 of 1971. The amount of suspended solids (SS) was measured by the filtration weight method in Appendix Table 8 and compared with the emission standards applied to specific establishments nationwide based on Article 3, Paragraph 1 of the Water Pollution Law. The results are shown in Table 6.

  According to the above experiments, including the case where one of the porous material (PS ash) or the inorganic fine powder (calcium carbonate) is not added, the radioactive material is effective approximately 98% or more by using the inorganic flocculant. However, by adding both of them, the cesium 137 having a removal rate of 98% or more can be completely removed until it reaches the detection limit. No. 2 to No. As is clear from the comparison in FIG. The test water of No. 2 was colorless and transparent and no coloration was observed. 3 to No. Although the concentration of the test water of No. 5 is different, in any case, brown coloration (which seems to be due to the oxidation of iron) occurs, the porous material (PS ash) is very fine particles in the recovered waste liquid. Although it is extremely effective for the removal of cesium 137 including ionic radioactive substances, depending on the amount of addition, there is still the possibility that radioactive substances may remain in the test water. In addition, it is recognized that the porous material (PS ash) having an addition content of about 35 wt% of 15 wt% or more and less than 40 wt% is extremely effective and appropriate for complete removal of radioactive materials. In addition, the inorganic flocculant shows excellent results in the agglomeration test and the environmental load substance measurement test. In the case of the inorganic coagulant (2), it can be made particularly suitable for discharge into public water systems.

A High-pressure water-absorbing washing machine 1 High-temperature high-pressure suction device 11 Water supply 2 Washing spinner 21 Rotating nozzle 22 Suction hole 3 Waste air waste liquid separation device 4 Waste liquid treatment tank 41 Drain pump 5 Flocculant 6 Designated waste

Claims (8)

  A powder-type flocculant having a radioactive substance removal function for removing radioactive substances contained in waste liquid of radioactive substance removal treatment or cleaning treatment, which is a cationic polymer flocculant for forming primary flocs, and flocs of fine particles Aluminum sulfate for promoting formation, nonionic and / or anionic polymer flocculants for forming secondary flocs, inorganic fine powder for sedimentation weight of secondary flocs, ultrafine particles or ionic radioactive Porous material for substance adsorption is mixed and contained, and the recovered waste liquid can be separated into clean water that can be drained on-site and secondary flocs containing suspended sediment containing radioactive materials that are stored in place. An inorganic flocculant for removing radioactive substances.   The radioactive flocculant for removing a radioactive substance according to claim 1, wherein the waste liquid of the radioactive substance removal treatment or washing treatment is used as a waste liquid for high-pressure water-absorbing washing using a high-pressure water-absorbing washing machine.   The porous material for adsorbing radioactive material is PS ash obtained by calcining paper sludge, so that fine fine particles or ionic radioactive material in the recovered waste liquid can be adsorbed freely. The inorganic flocculant for radioactive substance removal of description.   The inorganic flocculant for removing radioactive substances according to claim 2 or 3, wherein the PS ash is 5 to 60 wt%.   The inorganic flocculant for removing a radioactive substance according to claim 1, further comprising an insoluble inorganic substance having a specific gravity of 2 to 3 as a sedimentation accelerator for the inorganic fine powder. .   The slaked lime is additionally contained as a settling accelerator for the remaining primary floc in the secondary floc formation leakage by the nonionic and / or anionic polymer flocculant for forming the secondary floc. The inorganic flocculant for radioactive substance removal of 2, 3, 4 or 5.   In addition to the cationic polymer flocculant, aluminum sulfate, nonionic and / or anionic polymer flocculant, inorganic fine powder and porous substance, the water in the secondary floc of the aggregated sediment-containing suspension water is added. 7. A hydraulic substance which is retained as crystallization water in ettringite and which makes the secondary floc a solidified aggregated precipitate is additionally contained. An inorganic flocculant for removing radioactive substances as described in 1.   8. Instead of containing the hydraulic substance, the hydraulic substance is provided for separate post-packaging addition to be added to the secondary flock after separation of clean water and the secondary flock. The inorganic flocculant for radioactive substance removal of description.

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