JP2015016442A - Equipment and method for water quality clarification treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an interruption of decontamination work by effectively performing water quality clarification treatment of contaminated water contaminated with radioactive substances.SOLUTION: Contaminated water that contains a contaminant and needs water quality clarification treatment is supplied into an agitation vessel, the supplied contaminated water filled with a coagulant is agitated using an agitator, then is left standing to separate coagulated deposits from treated water and the separated treated water and coagulated deposits are independently taken out from the agitation vessel. For the purpose of the above process, first and second agitation vessels 2, 3 are provided, and channel switching means is provided so that different water quality clarification treatment can be performed in the first and second agitation vessels 2, 3, respectively, and the channel switching means enables contaminated water to be continuously supplied by switching channels with timing adjusted to entry into the agitation process by an agitator 8 in the first agitation vessel 2 to supply the second agitation vessel 3 with the contaminated water, thereby preventing an interruption of decontamination work.

Description

  The present invention relates to a water purification process apparatus and a water purification process that purifies contaminated water that contains sludge water such as sludge water, rainwater, drainage, etc., and radioactive substances, etc., and radioactive substances that require water purification treatment. Is related to the technical field.

In general, it is considered that radioactive materials diffuse into the atmosphere due to damage to nuclear reactors installed at nuclear power plants and the like. As radioactive materials diffused in this way, iodine 131, cesium 134, cesium 137, Representative examples include rhodium 106, cobalt 60, strontium 90, radium 226, uranium 234, uranium 235, uranium 238, and plutonium 239. Among such radioactive substances, cesium 134, cesium 137, and strontium 90, which are generated in large quantities, have a long half-life of about 30 years, which is a problem. Since the boiling points of these radioactive substances are 671 ° C. for cesium and 1382 ° C. for strontium and the boiling point of cesium is low, it is considered that radioactive cesium diffuses widely in the atmosphere.
The diffused radioactive cesium adheres to farmland, residential areas, school grounds, sewage sludge, debris, etc. in drainage, and falls into pools, water treatment plants, sewage treatment plants, rivers, etc. As environmental water flows into the sea area and pollution is expected to further spread, it is necessary to prevent the diffusion of radioactive materials and prevent exposure by taking early purification (decontamination) measures.
Especially in urban areas, purification (decontamination) work is required for efficient and efficient cleaning work with a small turn to quickly suck and collect the discharged wash water while preventing the splash of wash water. There are many methods that rely on human hands in the work, and it takes time to process the contaminated water collected by suction, resulting in interruption of the cleaning operation during the treatment time, and a device that can perform more efficient work. It is in the current situation being sought.
As a technique for removing contaminants such as radioactive substances, it has been proposed that the pollutants are coagulated and separated using a flocculant, thereby purifying the water containing the pollutants (polluted water). (For example, Patent Document 1).

JP 2012-247212 A

  However, in the case of coagulating and precipitating the pollutant using the flocculant, the flocculant is added to the contaminated water supplied to the stirring tank and stirred well, and then allowed to stand to separate the separated water and the aggregated precipitate, There is a problem that it takes time to take out the separated water and the coagulated sediment, and during this time, the supply of the contaminated water to the agitation tank is delayed, and the decontamination work is forced to be interrupted. There are issues to be solved.

The present invention has been created in view of the above-described circumstances and has been created for the purpose of solving these problems. The invention of claim 1 is a contamination that contains a pollutant and requires water purification treatment. Water is sucked at a negative pressure and supplied to a stirring tank, and the supplied contaminated water filled with a flocculant is stirred with a stirrer and then allowed to stand to separate into agglomerated precipitate and treated water In the water purification apparatus in which the separated treated water and the aggregated precipitate are separately taken out from the agitation tank, a plurality of the agitation tanks are provided, and each of the agitation tanks is switched by switching the flow path. It is provided with a flow path switching means for making it possible to perform another water purification process, and the flow path switching means is such that the agitation tank in which the water purification process has been performed has entered the agitation process by the agitator. Next, change the flow path at the right time. Is intended to supply of contaminated water to the position of the stirred tank, a water purification apparatus being characterized in that configured to perform the switching to forward the plurality of stirred tank.
The invention of claim 2 is characterized in that in the first half of the process in which the flocculant is supplied, the stirrer is controlled to rotate at high speed, and the second half of the process in which the aggregated precipitate grows is controlled to rotate at low speed. The water purification apparatus according to claim 1.
The invention according to claim 3 is the water purification apparatus according to claim 1 or 2, wherein the aggregated precipitate is supplied to a filter incorporated in an aggregate receiving container in which a water drainage passage is formed.
The invention according to claim 4 is a supply step of sucking the negatively-contaminated contaminated water containing a pollutant and requiring a water purification treatment into the stirring tank, and filling the supplied contaminated water with a flocculant. Stirring step of stirring things with a stirrer, separation step of separating the agglomerated precipitate and treated water by standing, and taking out the separated treated water and agglomerated sediment separately from the stirring tank In the water purification process method to be performed, the flow path switching means for configuring each of the agitation tanks so as to perform different water purification processes in each stirring tank by disposing a plurality of the agitation tanks and switching the flow paths. The flow path switching means switches the flow path in synchronization with the timing when the agitation tank that has been subjected to the water purification treatment has entered the agitation process by the agitator, and performs subsequent-order agitation. To supply contaminated water to the tank A water purification treatment method which is characterized in that the switching has been configured to run forward to the plurality of stirred tank.

According to the first and fourth aspects of the present invention, when the agitation tank preceded by the water purification process becomes the agitation process, the contaminated water is supplied in the subsequent agitation tank, and this is executed in order. As a result, the contaminated water decontaminated by the decontamination work can be supplied almost continuously, and the workability of the decontamination work is improved.
According to the invention of claim 2, it is possible to achieve a large growth of the precipitate aggregate while avoiding the flocculating agent from becoming lumpy and increasing the stirring and mixing ability of the flocculating agent, and an efficient purification treatment. Will be able to.
By setting it as invention of Claim 3, draining from the collect | recovered aggregate precipitate can be performed simultaneously with collection | recovery of an aggregate precipitate, and working efficiency improves.

It is a circuit diagram of a water quality purification processing apparatus. It is the flowchart figure which described the operation | work procedure in the 1st stirring tank. It is the flowchart figure which described the operation | work procedure in the 2nd stirring tank. It is the flowchart figure which described a part of work procedure in the 1st stirring tank which showed the other example. It is the flowchart figure which described a part of work procedure in the 2nd stirring tank which showed the other example. It is a front view of a water quality purification processing apparatus. It is a top view of a water quality purification processing apparatus. It is a side view of a water purification processing apparatus. It is a partially cutaway front view of an aggregate receiving container.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, taking as an example a decontamination process for those contaminated with radioactive substances. In the drawings, reference numeral 1 includes radioactive substances generated by decontaminating substances contaminated with radioactive substances using high-pressure washing water (the high-pressure decontamination apparatus is general-purpose and will not be described). A small-scale water purification apparatus for purifying radioactive substances (hereinafter referred to as “polluted substances”) from radioactive substance-contaminated water (hereinafter referred to as “contaminated water”). It is mounted on a possible gantry 1a and can be easily moved by being pushed and pulled by an operator. However, the first and second agitation tanks 2 and 3 and a suction device 4 are provided. However, the inlets 2a and 3a provided at the upper portions of the first and second stirring tanks 2 and 3 are connected to the first three-way switching valve 5 via the pipes 2b and 3b. Is further washed by discharging high-pressure washing water through the pipe 6a. It is connected to the contaminated water instantly by timing the suction port 6 for sucking a. By switching the flow path of the first three-way switching valve 5, the contaminated water sucked from the suction port 6 can be switched and supplied to the first and second stirring tanks 2 and 3, respectively.
Incidentally, in the water purification apparatus 1, the parts such as the gantry 1a, the stirring tanks 2 and 3, the control panel X, various hoses, and the filters 20 and 21 described later can be disassembled and assembled. Therefore, it is considered that each part can be easily carried by manpower and can be easily transported by truck.

  Further, suction ports 2c and 3c are formed in the upper portions of the first and second stirring tanks 2 and 3, and the suction ports 2c and 3c are connected to the second three-way switching valve 7 through the pipes 2d and 3d. However, the second three-way switching valve 7 is further connected to the suction machine 4 via a pipe 4a. By switching the flow path of the second three-way switching valve 7, the suction force (negative pressure) generated by driving the suction machine 4 can be switched and supplied to the first and second agitation tanks 2 and 3, respectively. ing.

  In the first and second agitation tanks 2 and 3, the first and second agitators 8 and 9, and the first and second water quantities for detecting the amount of water in the first and second agitation tanks 2 and 3, respectively. The detection sensors 10 and 11 and the first and second flocculant feeders 12 and 13 for introducing the flocculant into the first and second stirring tanks 2 and 3 are provided. When the flocculant is not charged, the input devices 12 and 13 can be shut off (sealed) from the outside air, and opened to allow the outside air to be introduced into the tank at the time of taking out treated water and agglomerated sediment described later. However, it is of course possible to separately provide an air inlet provided with an on-off valve for supplying outside air into each tank.

  Further, the aggregated sediment discharge pipes 14 and 15 provided with opening / closing valves 14a and 15a at the lower ends of the inclined bottom portions 2e and 3e of the first and second agitation tanks 2 and 3 are lower on the tip side. In order to promote the outflow of the coagulated sediment, it is connected in an inclined manner, and is above the bottom, and the coagulant is added to the contaminated water as described later to separate the treated water and the coagulated sediment. In this case, the treated water discharge pipes 16 and 17 are provided at a position higher than the surface layer of the precipitated aggregated sediment, and the treated water discharge pipes 16 and 17 are joined via the on-off valves 16a and 17a. As a result, the combined pipe 18 is provided with a pump 18a for extracting treated water, and the combined pipe 18 reaches the third three-way switching valve 19 where it is branched into the pipes 20a and 21a. It reaches the filters 20 and 21, The treated water is filtered by one of the first and second filters 20 and 21 when the third three-way switching valve 19 is switched, and is discharged via pipes 20c and 21c having check valves 20b and 21b. It has come to be. Incidentally, the reason why the first and second filters 20 and 21 are arranged in parallel and filtered by one of them is to facilitate the maintenance and replacement work of the filter and to contribute to the continuity of the decontamination work. Is.

Next, a control procedure for separating and removing contaminants from the contaminated water by the control panel (control device) X will be described with reference to a flowchart. First, as for the control procedure of the first stirring tank 2, when the system is started, an attached report lamp (not shown) is in an extinguished state, and it is determined whether or not it is the first time (S1). When it is determined that there is (YES), it is then determined whether or not the first water amount detection sensor 10 provided in the first stirring tank 2 is at a “Low” level that is set to a preset low water level ( S2) is performed, but if it is determined that the determination in S1 is not the first time (NO), it is further determined whether the second stirrer 9 is driven (S3), and the second stirrer 9 is driven The determination of S2 is made when it is determined (YES).
If the determination in S2 is YES, the decontamination operation is started in S4, the suction machine 4 is driven, the first three-way switching valve 5 is switched to the pipe 2b side, and the second three-way switching valve 7 is turned on. Switch to the piping 2d side. Thereby, the suction pressure by the suction machine 4 is supplied to the water supply port 6 via the pipe 4a, the second three-way switching valve 7, the pipe 2d, the first stirring tank 2, the pipe 2b, the first three-way switching valve 5, and the pipe 6a. Thus, the contaminated water generated by the decontamination work is supplied to the first stirring tank 2.

Next, a determination is made as to whether or not the water level of the first water amount detection sensor 10 is at a “High” level (S 5) assuming that the water level is a preset high water level, and “High” is determined (YES). Then, the reporting lamp is turned on, the decontamination work is stopped and the suction device 4 is stopped in S6, and the first stirrer 8 is driven in S7 and is preset from the first flocculant charging device 12. A sufficient amount of flocculant is introduced into the first stirring tank 2.
A determination is made as to whether or not the stirring time T1 set in advance for the first stirrer 8 has elapsed (S8). If YES is determined that it has elapsed, the first stirrer 8 is stopped in S9. To do. Whether or not the stop time of the first stirrer 8 has passed a stationary time T2 set in advance as the time when the substance contained in the treated water has agglomerated and settled (preliminarily determined in the previous experiment). If a determination (S10) is made and a YES determination is made that the stationary time T2 has elapsed, after opening the on-off valve 16a in S11, the water extraction pump 18a is driven. As a result, the treated water from which the aggregated precipitate has been separated and purified in the first stirring tank 2 passes through the pipes 16 and 18 and the third three-way switching valve 19, and either the first or second filter 20 or 21. What is supplied to and filtered is drained. The first and second filters 20 and 21 are alternately used to determine that the filtration capacity has decreased, and those having a reduced filtration capacity use the time during filtration on the other side to replace the filter. Thus, continuous filtration is possible.

  Then, a determination is made as to whether or not the water level of the first water amount detection sensor 10 has become the “Low” level (S12), and if it is determined that the water level has reached the “Low” level, the attached report lamp is turned off. At the same time, the treated water extraction pump 18a is stopped, and the opening / closing valve 16a is opened. In S14, the first opening / closing valve 14a is opened, and the aggregated sediment deposited in the first stirring tank 2 is taken out. Then, a determination is made as to whether or not the aggregated sediment has been removed (S15). If YES is determined that the aggregated sediment has been extracted, the first on-off valve 14a is closed and the process returns.

  Next, the control procedure of the second agitation tank 3 is basically the same as the control procedure of the first agitation tank 2 except that whether or not there is an initial determination of S1 is different. First, it is determined whether or not the first stirrer 8 has been driven (S16). If it is determined that the first stirrer 8 has been driven and YES is determined, then the second water amount detection sensor 11 provided in the second stirring tank 2 is preset. In step S17, it is determined whether the level is “Low” indicating that the water level is low. However, if YES is determined in step S17 as “Low” level, the result is determined in S18. While the dyeing operation is started, the suction machine 4 is driven, the first three-way switching valve 5 is switched to the pipe 3b side, and the second three-way switching valve 7 is switched to the pipe 3d side. Thereby, the suction pressure by the suction machine 4 is supplied to the water supply port 6 via the pipe 4a, the second three-way switching valve 7, the pipe 3d, the second stirring tank 3, the pipe 3b, the first three-way switching valve 5, and the pipe 6a. Thus, the contaminated water generated by the decontamination work is supplied to the second stirring tank 3.

Next, a determination is made as to whether or not the water level of the second water amount detection sensor 11 is a “High” level that is a preset high water level (S 19), and it is determined that it has become “High” (YES). Then, the reporting lamp is turned on, the decontamination operation is stopped and the suction device 4 is stopped in S20, and the second stirrer 9 is driven in S21 and a predetermined amount from the second flocculant feeder 13 The flocculant is fed into the second stirring tank 3.
A determination is made as to whether or not the stirring time T1 set in advance for the second stirrer 9 has elapsed (S22). If YES is determined that it has elapsed, the second stirrer 9 is stopped in S23. To do. Whether or not the stop time of the second stirrer 9 has passed a stationary time T2 set in advance as a time when a substance contained in the treated water has agglomerated and settled (preliminarily determined in the previous experiment). If a determination (S24) is made and a YES determination is made that the stationary time T2 has elapsed, in S25, the on-off valve 17a is opened, and then the treated water extraction pump 18a is driven. As a result, the treated water from which the aggregated precipitate has been separated and purified in the second stirring tank 3 passes through the pipes 17 and 18 and the third three-way switching valve 19, and either one of the first and second filters 20 and 21. What is supplied to and filtered is drained.

Then, a determination is made as to whether or not the water level of the second water amount detection sensor 11 has become the “Low” level (S26). If the determination is YES because it has reached the “Low” level, the attached report light is turned off. At the same time, the pump for draining the treated water 18a is stopped and the opening / closing valve 17a is opened (S27). Further, in S28, the second opening / closing valve 15a is opened to precipitate in the second stirring tank 3. Take out. Then, a determination is made as to whether or not the aggregated sediment has been removed (S29). If YES is determined that the aggregated sediment has been removed, the second on-off valve 15a is closed (S30) and the process returns. .
The precipitated agglomerate is supplied to the agglomerate receiving container 22, and the agglomerate receiving container 22 is filtered into a bottomed cylinder having a drain 22 a (water drainage path) formed at the bottom (or lower part). 23, and when the precipitate condensate is supplied into the filter 23, the water mixed with the precipitate aggregates escapes from the drainage channel, and the drained precipitate aggregates are removed. Efficient collection is possible. Here, the drain 22a is provided with an opening / closing valve, so that the sediment receiving container 22 to which the precipitate agglomerate is supplied is transported to another location where drainage or the like may be drained, and the opening / closing valve is opened here. The water filtered by the filter 23 can be drained, and the dripping of water can be prevented.

  In the present embodiment configured as described, first and second agitation tanks 2 and 3 are disposed, and supply of contaminated water by suction to the first and second agitation tanks 2 and 3 and a coagulant. To the second agitation tank 3 while the agitation with the agitators 8 and 9 with contaminated water added, separation of the agglomerated precipitate and the treated water by stationary, and removal of the treated water and the agglomerated sediment can be performed separately. As a result of the supply of contaminated water being performed in time with the first stirrer 8 being driven in the first stirring tank 2, the water purification process by the first and second stirring tanks 2 and 3 is performed. The contaminated water supply process, the agitation process, the separation process, and the extraction process are alternately performed in parallel, and for this reason, the supply of the contaminated water to the respective agitation tanks 2 and 3 is performed almost continuously. As a result, there is almost no interruption in the decontamination work, improving workability. That.

  Of course, the present invention is not limited to the above-described embodiment. For example, when it takes a long time for the separation process by stationary, the number of stirring tanks is further increased to three or more, and the water quality is preceded. In accordance with the timing when the agitation tank that has undergone purification treatment has entered the agitation process by the agitator, the flow path is switched to supply contaminated water to the agitation tank of the next rank, Concurrently supply contaminated water to the next agitation tank in time with the start of the agitation process, and sequentially supply contaminated water to the agitation tank in time with the start of the agitation process. Any configuration may be used.

Of course, the present invention is not limited to the above-described embodiment. For example, when the flocculant is likely to become lumps, the decontamination work of S6 and S20 is stopped, and the suction machine 4 The process of driving the first or second stirrer 8 or 9 after stopping the operation and supplying the flocculant until the first or second stirrer 8 or 9 in S9 or S23 is stopped, As shown in FIGS. 4 and 5, the first or second stirrer 8 or 9 is rotated at a high speed to avoid lumping of the flocculant. Can be considered.
That is, in S7-1 and S21-1, the first and second agitators 8 and 9 are rotated at high speed and the flocculant is supplied, and it is determined that the first agitation time T1x has elapsed (S8-1 and S22-1). ), The first and second agitators 8 and 9 are rotated at a low speed (S7-2, S21-2), and it is determined that the second agitation time T1y has passed (S8-2, S22-2) The first and second agitators 8 and 9 can be controlled to be stopped (S9, S23), so that the flocculant can be prevented from becoming lumps and can be grown into large precipitate agglomerates. Consideration. Incidentally, the speed reduction of the stirrers 8 and 9 can be performed not in two stages but in multiple stages, and of course, may be a continuous speed reduction.

  INDUSTRIAL APPLICABILITY The present invention can be used in a water purification device and a water purification method that purify contaminated water that contains a pollutant such as a radioactive substance and requires water purification. Also, it can be used for clean water treatment of contaminated water at building construction sites, clean water treatment by purification of rainwater, drainage, etc.

DESCRIPTION OF SYMBOLS 1 Water purification processing apparatus 2, 3 1st, 2nd stirring tank 4 Suction machine 8, 9 1st, 2nd stirring machine

Claims (4)

  After the contaminated water containing the pollutant and requiring water purification treatment is sucked at a negative pressure and supplied to the agitation tank, the supplied contaminated water filled with the flocculant is agitated with an agitator In the water purification apparatus that separates the aggregated precipitate and the treated water by standing, and separates the separated treated water and the aggregated precipitate from the stirred tank, a plurality of the stirred tanks are provided. And a flow path switching means for configuring each of the agitation tanks so that each water purification process can be performed by switching the flow path. The flow path switching means is preceded by a water quality purification process. The agitation tank is switched to the timing when the agitation tank has entered the agitation process by the agitator, and the contaminated water is supplied to the agitation tank of the subsequent rank. It was configured to run forward to the stirring tank Water purification apparatus for treating symptoms.   The stirring step is characterized in that the stirrer is controlled to rotate at high speed in the first half of the process in which the flocculant is supplied and is controlled to rotate at low speed in the second half of the process in which the aggregated precipitate grows. Water purification equipment.   The water purification apparatus according to claim 1 or 2, wherein the aggregated precipitate is supplied to a filter incorporated in an aggregate receiving container in which a water drainage passage is formed.   Supply process for sucking contaminated water containing pollutants and requiring water purification treatment at a negative pressure and supplying it to the stirring tank, stirring the supplied contaminated water filled with a flocculant with a stirrer Water quality purification, in which a separation step of separating the agglomerated precipitate and the treated water by standing, a removal step of taking out the separated treated water and the agglomerated sediment separately from the agitation tank, is sequentially performed. In the treatment method, a plurality of the agitation tanks are provided, and flow path switching means is provided for configuring each of the agitation tanks to perform different water purification processes by switching the flow paths. The path switching means switches the flow path at the timing when the agitation tank that has been subjected to the water purification process in advance has entered the agitation process by the agitator, and supplies the contaminated water to the agitation tank of the subsequent rank. This switching is performed as described above. Water purification treatment method which is characterized in that configured to perform the forward to the stirred tank number.

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