Atmospheric pressure flotation treatment method using turbid water treatment facility

Abstract

To provide a system which employs an atmospheric pressure flotation treatment method using chemicals and requires a certain amount of running costs, but the chemicals electrochemically adsorb air bubbles and solids to obtain highly clarified treated water, in addition, since the apparatus and the facility are formed in a compact shape, the tank can be divided and transported by trailer or truck, and assembling work can be easily performed on site.SOLUTION: A treatment facility includes a rapid agitator 3 that injects chemicals into raw water (turbid water), a tube-shaped slow agitator 5 that chemically reacts the raw water injected with chemicals, and a flotation treatment device 6 which has a drainage pipe 604 with a water collection port 604a to collect treated water provided in an inner cylinder 602 that separates raw water into scum and treated water, the lower part of which is fixed away from the bottom plate 603 of a water tank 601, a jet outlet 605a of a raw water input pipe 605 is placed inside the inner cylinder 602.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technology for purifying and treating turbid water generated in quarries, construction sites, factories, agricultural and fishery related facilities, waste treatment businesses, etc., and in particular to a turbid water treatment facility that treats turbid water by floating it at normal pressure. Atmospheric pressure levitation using It relates to a processing method. [Background technology]

[0002] Turbid water is almost always discharged in construction work where groundwater levels are high. Turbid water discharged must comply with the standards set by the Water Pollution Control Law and local ordinances established by each prefecture. Turbid water is strictly regulated by the Water Pollution Control Law and local ordinances.

[0003] Conventionally, when treating turbid water, a two-stage treatment facility (apparatus) was used: flotation treatment facility (apparatus) and coagulation and sedimentation treatment facility (apparatus). The flotation treatment method (apparatus) is a technology that separates suspended solids (oil, etc.) that have a lower specific gravity than water by floating them on the water surface. Generally, the most common flotation treatment method (apparatus) is the pressurized flotation method. This method is widely used due to its excellent efficiency and cost-effectiveness.

[0004] In the floating treatment method (apparatus), first, the raw water (turbid water) is flowed into a raw water tank and stored there. In order to make the raw water (turbid water) uniform, it is transferred to a raw water adjustment tank. Note that this raw water adjustment tank is not a required facility (apparatus). Next, chemicals are added and the raw water (turbid water) to which chemicals have been added is fed into a flotation tank where fine air bubbles are attached to the suspended solids in the turbid water, reducing the apparent specific gravity of the suspended solids, causing them to float to the water surface and be discharged as scum.

[0005] Fig. 18 is a cross-sectional view showing an example of a conventional flotation treatment device. Fig. 19 is a plan view showing an example of a conventional flotation treatment device. The conventional flotation treatment device 901 shown in the figure has a raw water flow rate Q of 50 m 31 shows a treatment tank of a / H type. This flotation treatment device 901 is a rectangular parallelepiped water tank 902. In the left half of this water tank 902, an input pipe 903 for inputting raw water (turbid water) is placed in the vertical center position of the water tank 902 so that its outlet 904 faces upward. In the right half of the water tank 902, a drain pipe 905 for collecting treated water (treated water) is placed. The drain pipe 905 is placed in the water tank 902 so that the collection port 906 of the drain pipe 905 is located at the upper surface of the water tank 902. A partition plate 907 is attached to divide the water tank 902 into right and left halves so that the raw water and the treated water do not become turbid. This partition plate 907 is placed between the input pipe 903 and the drain pipe 905. The lower part of the partition plate 907 is separated from the bottom plate 902a of the water tank 902, so that the treated water moves through it.

[0006] In this conventional flotation treatment device 901, scum floats to the top of the suspended treated water that is sprayed toward the water surface from the nozzle 904 of the input pipe 903, and the treated water from which the scum has separated moves to the right half of the drain pipe 905. At this time, the floating scum is prevented from collecting in the drain pipe 905 by a partition plate 907. This scum is scooped up, and the muddy water is separated into scum and treated water.

[0007] Many techniques for treating turbid water have been proposed in this way. For example, Patent Document 1, JP 2008-119563 A, "Turbid Water Treatment Apparatus," proposes a turbid water treatment apparatus that is provided on a portable stand with a raw water tank, a slow stirring tank, a first supplying means for supplying raw water from the raw water tank to the slow stirring tank, a flocculant supplying means for supplying flocculant to a flocculant injection section in the middle of the first supplying means, and a second supplying means for supplying treated water from the slow stirring tank to a settling separation tank and the like. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2008-119563 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the conventional flotation treatment device 901 shown in the cross section of Fig. 18 and the plan view of Fig. 19, when the suspended treated water jetted out from the jet outlet 904 of the input pipe 903 toward the water surface is separated into scum and treated water, the scum spreads over the entire water surface with the water current and swirls, making it difficult to scrape the scum together, as shown in the cross section of Fig. 18. This results in a problem of a decrease in the removal rate of scum.

[0010] In addition, the floating treatment device 901 has a flow velocity V L In order to keep the area constant, the opening height at the bottom center of the water tank 902 is set to h = 1300 mm, and the separation area A L (1.7m 2 This not only increases the height of the floating treatment device 901, but also increases the volume.

[0011] Raw water flow rate Q=200m 3 In the case of a large-scale treatment device such as the 1 / H, the volume of the floating treatment device 901 increases, which can make transportation difficult. When transporting by trailer or truck, there are problems such as the inability to transport the tank in parts, the inability to assemble the tank on site, and the inability to secure a yard.

[0012] In the conventional method of injecting chemicals, the chemicals may not mix evenly after being added to the stored raw water, such as by attaching air bubbles to the water. If the treated water is then subjected to flotation separation treatment in this state, the clarity of the treated water may be poor. In addition, the speed of the separation treatment must be slowed down, which increases the treatment time.

[0013] In the conventional method of determining the amount of chemicals to be injected, the chemicals to be used for flotation treatment were determined by collecting turbid water at the construction site and determining the operating conditions of the flotation treatment device used at the site. If the appropriate amount of chemicals was not determined, there were many cases where air bubble adhesion was insufficient, and the clarity of the treated water was likely to be poor. In addition, when the adjustment of the amount of chemicals injected was complicated, the treatment flow rate was lowered for operation, which resulted in a problem of a decrease in the amount of treatment per hour.

[0014] The "turbid water treatment device" described in Patent Document 1 had the problem that it required a raw water tank, a slow stirring tank, and a sedimentation separation tank, each with its own feeding means, which tended to require a large treatment installation space.

[0015] The present invention was invented to solve such problems. That is, the object of the present invention is to provide a turbid water treatment system that uses chemicals to electrochemically adsorb air bubbles and solids, which requires a certain degree of running cost, but produces highly clear treated water. In addition, by making the device and equipment compact, it is possible to transport the tanks separately by trailer or truck, and to easily assemble the equipment on-site. Atmospheric pressure levitation using The present invention aims to provide a processing method. [Means for solving the problem]

[0016] The atmospheric flotation treatment method of the present invention is a method for treating turbid water generated at quarries, construction sites, factories, agricultural and fishery facilities, and waste treatment facilities, using a turbid water treatment facility that includes a raw water tank (1) for storing turbid water (raw water) to adjust the amount of water to be treated, a rapid mixer (3) for injecting chemicals into the raw water, a slow mixer (5) for chemically reacting the raw water to which the chemicals have been injected, and a flotation treatment device (6) having an inner cylinder (602) disposed inside the tank (601) with its lower part separated from the bottom plate (603) of the tank (601), First, When determining the amount of raw water to be pumped from the raw water tank (1), the raw water and a chemical agent are placed in a floating jar tester (401) on-site, and the time it takes for the scum to float after a specified time is measured. The amount of raw water to be treated per hour and the amount of chemical agent to be added are calculated from the capacity of the floating treatment device (6), and the flow rate of the pump (7) of the raw water tank (1) is determined. In the rapid mixer (3), , the amount determined by the floating jar tester (401) Add chemicals and then chemically react with the raw water in a slow mixer (5). Next, the raw water that has been chemically reacted with the chemical is sprayed into the inner tube (602) of the flotation treatment device (6), causing the scum to float in the inner tube (602), and then scooped up and discharged as is. The treated water is separated from scum in the inner cylinder (602) and made to settle, and this treated water moves upward from the lower part of the inner cylinder (602) to between the inner cylinder (602) and the water tank (601), where it is collected so as to overflow, and is then discharged to complete the treatment.

[0017] In the rapid mixer (3), when adding a plurality of chemicals to raw water, the chemicals can be added using a pump that can provide a continuous non-pulsating flow by arranging two diaphragms opposite each other. Effect of the Invention

[0018] In the present invention, by making the device and equipment compact, the device can be easily transported in sections by trailer or truck, and can be easily assembled on-site. In particular, in the flotation treatment device (6), the raw water (muddy water) to which chemicals have been added is discharged upward from the center of the inner tube (602), and after being slowed down by the baffle plate (606), reaches the water surface. At this time, light flocs become scum that floats on the water surface. In addition, the scum is collected within a narrow range inside the inner tube (602) and near the center of the water surface (in a circular shape) by the action of the baffle plate (606), making it easier to scrape it up, and the efficiency of removing the scum is improved. Chemicals are used to electrochemically adsorb air bubbles and solid matter, and highly clear treated water is obtained using the atmospheric pressure flotation treatment method.

[0019] The treated water from which the scum has been separated settles down from the bottom of the inner cylinder (602) into the water tank (601). It then moves between the inner cylinder (602) and the inner wall of the water tank (601) and is discharged from the water collection port (604a) provided on the water surface. In this way, the miniaturization of the floating treatment device (6) can solve various problems such as transportation restrictions, the need for on-site work, and the need to secure a large site. [Brief description of the drawings]

[0020] [Figure 1]FIG. 1 is a front view showing the overall configuration of a turbid water treatment facility used in the atmospheric flotation treatment method of the present invention, with a portion shown in vertical cross section. [Diagram 2] FIG. 1 is a plan view showing the overall configuration of a turbid water treatment facility used in the atmospheric flotation treatment method of the present invention. [Diagram 3] FIG. 2 is a flow diagram showing the process of water treatment using various machines of the turbid water treatment equipment used in the atmospheric flotation treatment method of the present invention. [Figure 4] FIG. 1 is a schematic explanatory diagram showing the movement speeds of scum and treated water in a typical flotation treatment device. [Diagram 5] FIG. 1 is a schematic front view showing a floating jar test apparatus. [Figure 6] FIG. 2 is a schematic diagram showing a method for separating treated water and scum using a floating jar tester. [Figure 7] 1 is a graph showing test results of measurement data of mean floc floating time and turbidity. [Figure 8] FIG. 2 is a schematic explanatory diagram showing a normal drug injection mixing pattern. [Figure 9] FIG. 1 is a schematic explanatory diagram showing a pattern of drug injection into piping by a diaphragm pump. [Figure 10] FIG. 13 is a schematic diagram showing a drug injection pattern by a pump. [Figure 11] FIG. 1 is a plan view showing a rapid mixer that utilizes piping flow velocity. [Figure 12] FIG. 2 is an explanatory diagram showing the internal state of a rapid mixer. [Figure 13] FIG. 2 is an explanatory diagram showing the mixed state of raw water (turbid water) and a chemical agent. [Figure 14] FIG. 2 shows a slow chemical injection mixer, where (a) is a front view and (b) is a plan view. [Figure 15] FIG. 1 shows an example of a simply assembled piping, where (a) is a straight pipe, (b) is an elbow pipe (curved pipe), (c) is a cross-sectional view of the connected state, and (d), (e), and (f) are schematic diagrams of the connected state. [Figure 16] FIG. 2 is a cross-sectional view showing a normal pressure flotation treatment device constituting the turbid water treatment equipment used in the treatment method of the present invention. [Figure 17]FIG. 2 is a plan view showing a normal pressure flotation treatment device constituting the turbid water treatment equipment used in the treatment method of the present invention. [Figure 18] FIG. 1 is a cross-sectional view showing an example of a conventional floating treatment device. [Figure 19] FIG. 1 is a plan view showing an example of a conventional floating treatment device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] This invention is a compact water treatment device that treats raw water (turbid water) generated at sites such as quarries, construction sites, factories, agricultural and fishery facilities, and waste treatment businesses by floating suspended solids (oil, etc.) that have a lower specific gravity than water to the surface of the water. Normal pressure floating treatment method using It is. EXAMPLES

[0022] <Overall configuration of turbid water treatment equipment> Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of the present invention. Used in atmospheric floating processing method FIG. 2 is a front view showing the overall configuration of the turbid water treatment equipment of the present invention, with a portion shown in vertical section. Used in atmospheric floating processing method FIG. 3 is a plan view showing the overall configuration of the turbid water treatment equipment of the present invention. Used in atmospheric floating processing method FIG. 1 is a flow diagram showing a process for performing water treatment using various machines in a turbid water treatment facility. The present invention Used in atmospheric floating processing method The muddy water treatment equipment is transported by trailer or truck to sites such as quarries, construction sites, factories, agricultural and fishery-related facilities, and waste treatment plants, and is assembled on-site to treat muddy water into clean water. Used in atmospheric floating processing method The turbid water treatment facility mainly comprises a raw water tank 1 for securing a constant amount of raw water, a chemical injection tank (2) for storing chemicals (chemicals), and a chemical injection device 4 consisting of a rapid agitator 3. Downstream of the rapid agitator 3 is a slow speed agitator (reaction tube) 5 which uses an in-pipe stirring method, and downstream of the slow speed agitator (reaction tube) 5 is a flotation treatment device 6. Scum separated from the treated water in the flotation treatment device 6 is removed by a scraper provided above the device (not shown).

[0023] The present invention Used in processing methods The materials used for the floating treatment device 6, raw water tank 1, chemical injection tank 2, rapid mixer 3, slow mixer (reaction tube) 5, etc., in the turbid water treatment facility are determined based on the corrosiveness of the turbid water to be treated. For example, iron, steel, alloys with iron as the main component such as stainless steel, and other non-ferrous metals are used. Furthermore, synthetic resins such as polyethylene (PE) and fiber reinforced plastic (FRP), and concrete can also be used.

[0024] Scum, also known as floating sludge, is a thick, sponge-like layer of floating sludge that forms on the surface of the water when suspended solids, fibers, oils, lipids, and bacteria in the turbid water rise to the surface due to gases generated by the decay and fermentation of organic matter in the raw water (turbid water). It floats on the water surface of the treatment equipment and comes in a variety of sizes, from fine particles to large lumps over 30 cm in size. The treated water is purified by the floating treatment device 6. The treated water is mainly the raw water (turbid water) from which scum has been separated. This treated water may be discharged directly into public water areas or may be discharged into public water areas after being treated again.

[0025] <Raw water tank> The raw water tank 1 is a tank for temporarily storing raw water, i.e., turbid water generated at sites such as quarries, construction sites, factories, agricultural and fishery-related facilities, and waste treatment businesses. It is a tank for adjusting the amount of water when supplying it to the flotation treatment device 6. The raw water is transported to the downstream rapid mixer 3 using a pump 7. In the present invention, it is preferable that the length of one side of the opening of the tank is within about 1.5 m to 2.0 m, and the height of the tank is within about 2.0 m to 2.5 m so that it can be transported to the construction site by trailer or truck.

[0026] <How to determine the amount of drug to be injected> Fig. 4 is a schematic explanatory diagram showing the moving speeds of scum and treated water in a typical flotation treatment device. Fig. 5 is a schematic front view showing a flotation jar tester. Fig. 6 is a schematic explanatory diagram showing a method for separating treated water and scum using the flotation jar tester. When operating a flotation treatment device used in turbid water treatment facilities at normal pressure, it is necessary to know the dosage of chemicals in advance. This preliminary confirmation test, called a "jar test," is performed simply using a graduated cylinder. In conventional jar tests, the dosage of chemicals, the flotation speed of flocs, treatment time, turbidity, etc. are measured, but these measurements vary from person to person, making it difficult to know the exact dosage of chemicals.

[0027] When determining the amount of chemical to be injected in turbid water treatment equipment, the mixing amount is determined using a jar tester for normal pressure flotation treatment (flotation jar tester). As shown in the schematic diagram of Figure 4, the flotation treatment device utilizes the phenomenon that flocs tend to rise to the surface of the water to separate the flocs into a mass of flocs (scum) floating on the water surface and treated water below the surface. In this treatment device, the average descending speed of the treated water is V L (constant), the condition for flocs to float is number This is the case when condition 1 is satisfied. That is, V F >V L When , the flock is V F -V L It rises to the surface and turns into scum at a speed of V F <V L When , the flock is V L -V F When separating turbid water into scum and treated water, it is important to pretreat the raw water (turbid water) so that this condition is met.

[0028]

number

[0029] The flotation jar test is a confirmation test carried out before operating a flotation treatment device. It is usually carried out simply using a measuring cylinder. For this confirmation test, a flotation jar tester 401 shown in Figure 5 is used. Figure 6 is a schematic explanatory diagram showing a method for separating treated water and scum using a flotation jar tester. The principle diagram shown on the right side of Figure 6 shows the flotation state of flocs when raw water and chemicals are added, stirred, and then the flocs are left to stand on a table. Floc flotation speed V F When the flocs pass through the water depth H2 from the bottom of the vessel to the valve 402 at a constant speed (average speed), the floating time t crf Using number Define it as 2.

[0030]

number

[0031] In order to grasp the state of the floating treatment device in FIG. 6 in advance using the floating jar tester 401, the condition of the formula 1 must be satisfied. number 2 number Substituting into 1, the new condition for the average floc floating time is as follows: number 3 is obtained.

[0032]

number

[0033] Mean time to float flocs t crf can be calculated from the dimensions of the floating jar tester 401 and the floating treatment device. crf The three patterns are shown below, showing how flocs rise when a certain amount of water is applied.

[0034] (1) Pattern 1: V F <V L (=Q / A L ), the flocs do not reach the position of the valve 402. This pattern is V L V FBecause they are larger, in a flotation treatment system the flocs fall down as treated water. (2) Pattern 2: V F =V L (=Q / A L ), the flocs reach the position of the valve 402. (3) Pattern 3: V F >V L (=Q / A L ), the flocs pass through and rise to the position of the valve 402. This pattern is F V L Because they are larger, the flocs float as scum in flotation treatment equipment. As a result of the above, the floating jar tester 401 is left stationary and crf When the valve 402 is closed after this time, the water above the valve 402 can be separated into scum and treated water below the valve 402.

[0035] <Design of the floating jar tester> FIG. 5 is a front view showing an example of a floating jar tester. A valve 402 is provided at a position (H2=231 mm) where 500 mL of raw water has been poured into a floating jar tester 401. In this floating jar tester 401, raw water is poured up to the raw water pouring scale 403 to perform the test. As a preparation before starting the flotation jar test using the flotation jar tester 401, it is necessary to determine the operating conditions of the flotation treatment device to be used on-site. 3 This shows the operating conditions for the / H type flotation treatment device. Items 1 and 2 are values ​​that can be known in advance from the treatment plan. On the other hand, items 3 and 4 require calculation as shown in the remarks. In particular, item 4, the maximum value of the average floc flotation time t crf Understanding (sec) is extremely important when performing the floating jar test.

[0036] [Table 1]

[0037] FIG. 7 is a graph showing the test results of the mean floc floating time and turbidity measurement data. This time, we used a floating jar tester (a ready-made measuring cylinder that is slightly smaller than the one in Figure 5) and conducted the test under the following conditions. In this test, in order to confirm the floating condition, the floating time was divided into three stages and data was collected. (1) Raw water: Raw water concentration: Turbidity 642 degrees (2) Medication amount... Polyaluminium chloride (PAC): 15 ppm, Surfactant FA-3: 2 ppm, Cationic polymer flocculant ZK: 1 ppm, Anionic polymer flocculant ZA: 2 ppm

[0038] Figure 7 shows the test results, which are the measurement data of the mean floc floating time and turbidity. The mean floc floating time is the time elapsed from leaving the jar test device 401 still after mixing the raw water and chemicals until the valve is closed. The turbidity (degrees) is the value measured by taking out the bottom layer water (water depth H2 = 124 mm) when the valve 402 is closed.

[0039] Based on the results of FIG. 7, if the maximum value of the floc floating time in Table 1, tcrt=12 seconds, is given, the turbidity of the treated water at this time will be 14 degrees (corresponding to SS=14 mg / L) according to the graph shown in FIG.

[0040] <Method for advanced treatment> There are two methods to achieve advanced treatment with a target turbidity of 10 degrees (equivalent to SS = 10 mg / L) or less. One is t crf This is a method of fine-tuning the amount of chemicals injected until the turbidity of the treated water clears the target turbidity of 10 degrees at time t12 seconds. Another method is to operate the system by lowering the treatment flow rate to achieve the target turbidity. In other words, to achieve the target turbidity of 10 degrees or less based on the test data in Table 2 and Figure 7, crf It is thought that about 14 seconds is required. crf If the treatment time is extended to 14 seconds, the treatable raw water flow rate is Q = 25 m, as shown in Table 1. 3 / H or less. When the adjustment of the drug injection amount is complicated like this, it is effective to process it slowly over time.

[0041] The following points should be noted when using the floating jar tester 401 shown in FIG. (1) Determine the operating conditions of the flotation treatment device to be used on-site. (2) The maximum value of the mean time for floc floating in the treated water turbidity is t crf Determine the amount of chemical to be injected so that the target turbidity is achieved. (3) When the adjustment of the amount of chemicals injected is complicated, operate the system by lowering the treatment flow rate (t crf In some cases, a method that extends the time required for the

[0042] <Method of drug injection> Fig. 8 is a schematic diagram showing a normal chemical injection and mixing pattern, Fig. 9 is a schematic diagram showing a chemical injection pattern into a pipe by a diaphragm pump, and Fig. 10 is a schematic diagram showing a chemical injection pattern by a pump. The most common method of injecting chemicals into pipes at construction sites, such as civil engineering, is to use a diaphragm pump. Since a diaphragm pump repeatedly sucks in and discharges chemicals in one stroke, the flow of chemicals in the pipes pulsates.

[0043] When using two diaphragm pumps to inject and mix two types of chemicals (chemicals A and B) and then stir them, the mixing pattern shown in Figure 8 is possible. This conventional diaphragm pump method has the following problems. The mixed area in the piping is reduced. The state shown in Figure 8 is an example in which the diaphragm pumps for chemical A and chemical B are not synchronized and the phase difference is large, and the mixed area of ​​the two chemicals (the shaded area of ​​A+B) is relatively small. In addition, since the injection of the two chemicals was not controlled, the ratio of the mixture of the two chemicals (the shaded area of ​​A+B) changed every time the diaphragm pump was operated, which tended to result in unstable operation.

[0044] When mixing two types of chemicals, the following two methods can be considered. There is a method to feed a mixture of two chemicals in advance. There is a method to mix two chemicals (chemicals A and B) in advance and feed this with one diaphragm pump. This makes it possible to save on chemical tanks and diaphragm pumps. However, because the diaphragm pump repeatedly sucks in and discharges as shown in Figure 9, only half of the chemicals in the piping are fed, and this is what is stirred. In other words, the remaining half of the piping is stirred without being fed with chemicals, and this method is prone to uneven mixing.

[0045] Next, there is the continuous drug injection method using a pump. This pump is a drug injection pump that allows for a continuous flow without pulsation by arranging two diaphragms facing each other. By using this, it is possible to continuously inject drugs in the piping, as shown in Figure 9, as shown in Figure 10. In addition, even if chemicals A and B shown in FIG. 8 are pumped separately, they can be pumped continuously, so that the mixed area of ​​A and B is continuous, and good mixing results can be obtained.

[0046] <Rapid Mixer> Fig. 11 is a plan view showing a rapid mixer that utilizes piping flow velocity. Fig. 12 is an explanatory diagram showing the internal state of the rapid mixer. Fig. 13 is an explanatory diagram showing the mixed state of raw water (turbid water) and chemicals. In the atmospheric pressure flotation treatment device 6, chemicals must be added before the raw water is sent to the treatment tank through piping. In order to add chemicals, an in-pipe mixing method is used, in which the chemicals are injected into the piping and then immediately mixed in the pipe, making the device more compact. In the in-pipe mixing method, mixing can be done quickly or slowly depending on the type of chemical.

[0047] The rapid mixer 3, together with the chemical injection tank 2, constitutes the chemical injection device 4. The rapid mixer 3 has a chemical injection port 302 on the upstream side of a cylindrical body 301, and a mixer 303 is provided downstream adjacent to this chemical injection port 302. In the illustrated example, the chemical injection port 302 is represented by a black circle. A pipe from the chemical injection tank 2 is connected to this chemical injection port 302. The mixer 303 is also attached at several points inside the cylindrical body 301. This rapid mixer 3 is used to electrically charge fine particles in the turbid water to break them into small clumps. Examples of chemicals (chemical liquids) include, Polyaluminium chloride (PAC), Surfactant (FA-3), Cationic polymer flocculant (ZK), Anionic polymer flocculants (ZA) are used.

[0048] These chemicals and air are continuously injected into the rapid mixer 3 by the pump in the chemical injection tank 2, and are immediately rapidly mixed by the mixer 303, which rotates at high speed due to the flow rate. Note that it is also possible to use an impeller instead of the mixer 303 for mixing. The type, amount and injection sequence of the chemicals to be injected are determined by the floating jar test. In this rapid mixer 3, it is important to rapidly mix with the mixer 303 immediately after continuously injecting the chemicals and air.

[0049] 12 shows an example in which five mixers 303 are used in the rapid mixer 3, but the number is not limited to five. If mixing is insufficient, it is necessary to increase the number of mixers 303.

[0050] Figure 13 shows the mechanism of mixing by chemical injection and rapid mixing in this rapid mixer 3 when raw water passes through the piping. For example, first the chemicals are injected in the order of polyaluminum chloride (PAC), followed by surfactant (FA-3), and each time they are mixed by mixer 303. Next, air is injected with an air compressor and mixed. Subsequently, chemical injection and mixing are carried out in the order of cationic polymer coagulant (ZK) followed by anionic polymer coagulant (ZA). Finally, all the chemicals and air are completely mixed with the raw water. After that, it is moved to the next slow speed mixer 5.

[0051] Here, each chemical needs to be supplied and mixed in a timely manner. For this purpose, it is preferable to continuously inject each chemical using a non-pulsating chemical injection pump. Air also needs to be continuously injected using an air compressor (not shown).

[0052] <Slow speed agitator (reaction tube)> FIG. 14 shows a slow-speed stirrer (reaction tube), where (a) is a front view and (b) is a plan view. After rapid mixing, the final injection of an anionic polymer coagulant (ZA) breaks the clumps of fine particles in the turbid water into larger flocs. The flocs mix with FA-3 and air and rise to the water surface. The agitator shown in the figure is an example of a slow agitator 5 with a tube wound several times. The turbid water injected with chemicals is slowly mixed in this reaction tube by centrifugal force. In order to prevent the turbid water injected with chemicals from being disturbed by excess air, etc., the piping structure is designed to be upwardly inclined so that water is injected from the inlet at the bottom and discharged from the outlet at the top, as shown in Figure 14(a). A certain amount of reaction time is required to form appropriate flocs. In the slow agitator 5 shown in the figure, the reaction time is adjusted by the length of the reaction tube. If the reaction time is long, the length of the reaction tube is increased, and if the reaction time is short, the length of the reaction tube is decreased. The slow agitator 5 shown in the front view of Figure 14(a) is wound four times, but this is only one example and it is of course not limited to this four winding.

[0053] FIG. 15 shows an example of a simply assembled piping, where (a) is a straight pipe, (b) is an elbow pipe (curved pipe), (c) is a cross-sectional view of the connected state, and (d), (e), and (f) are schematic diagrams of the connected state. For the slow-speed agitator (reaction tube) 5, a unit tube is used which is compact, easily transportable, easily assembled on-site, and highly versatile. Figure 15(a) shows a unit tube of straight pipe 501. (b) shows a unit tube of elbow pipe (curved pipe) 502. As shown in Figure 15(c), each unit tube has flanges 503 at both ends, and these flanges 503 are joined together and connected using connectors 504 which enclose and clamp these parts. By combining the straight pipes 501 and elbow pipes (curved pipes) 502, piping of various shapes can be made as shown in (d), (e), and (f).

[0054] <Configuration of the atmospheric pressure floating treatment device> FIG. 16 shows the present invention Used in processing methods 17 is a cross-sectional view showing an atmospheric pressure flotation treatment device constituting the turbid water treatment facility of the present invention. The present invention Used in processing methods The atmospheric pressure flotation treatment device (flotation treatment device) 6 constituting the turbid water treatment facility has a rectangular inner cylinder 602 disposed inside a rectangular parallelepiped water tank 601 with its lower edge 602a spaced apart from the bottom plate 603 of the water tank 601. The upper edge 602b of the inner cylinder 602 is disposed at the same height as the upper edges 602b of the side plates of the water tank 601. The upper edge 602b of the inner cylinder 602 needs to be positioned higher than a water collection port 604a of a drainage pipe 604, which will be described later. This is because there is a risk that scum separated from the turbid water may be mixed into the treated water.

[0055] The illustrated atmospheric pressure flotation treatment device 6 has a rectangular parallelepiped water tank 601 and a square inner cylinder 602. This is based on the consideration of the size and capacity that can be loaded within the width of the trailer or truck used for transportation. The atmospheric pressure flotation treatment device 6 is not limited to a square shape. It can also be cylindrical or polygonal.

[0056] In the normal pressure flotation treatment device 6, an input pipe 605 for inputting raw water (turbid water) is arranged so that its outlet 605a is located at the center of the inner cylinder 602 in a plan view. The outlet 605a is arranged so as to face upward and at a vertically intermediate position of the water tank 601.

[0057] A baffle plate 606 is attached to the nozzle 605a so that the flow path of the muddy water coming out of the nozzle 605a is oriented perpendicular to the direction of the water being ejected. The baffle plate 606 serves to reduce the flow rate of the ejected muddy water as much as possible and collect the scum around the nozzle 605a, making it easier to separate the scum from the treated water.

[0058] In the illustrated example, a thin inverted cone-shaped baffle plate 606 is shown, but a thick inverted cone-shaped plate may be used instead. A simple disk may also be used. The baffle plate is not limited to a disk, and a hexagonal plate or other polygonal plate may be used. Furthermore, the baffle plate 606 may have any shape as long as it prevents the muddy water sent to the inner cylinder 602 from spurting out upward and allows the muddy water to accumulate in the "central separation area" of the inner cylinder 602. For example, the baffle plate 606 may be a member having a spherical shape, an oblate ellipsoid like a "go stone," a flat spindle shape like an "abacus piece," or the like.

[0059] In this water tank 601, purified water (treated water) is collected and discharged from a drain pipe 604. This water collection pipe 604 is disposed between the side wall of the water tank 601 and the inner cylinder 602, at an upper position of the normal pressure flotation treatment device 6, so that a water collection port 604a is located at the upper surface position of the water tank 601.

[0060] <Treatment method of atmospheric pressure flotation treatment device> In the atmospheric pressure flotation treatment device 6 of the present invention, the suspended treated water sprayed upward from the nozzle 605a of the input pipe 605 hits the baffle plate 606 and is decelerated. Scum, which is a solid matter, has the property of moving while touching an object (baffle plate 606) due to the action of surface tension, and therefore the scum that hits the baffle plate 606 tends to move along the outer shape of the baffle plate 606. This scum floats up in a circular shape. The floated scum is scooped up as it is. At this time, the floated scum floats up inside the inner cylinder 602. In this way, the scum and the treated water are separated.

[0061] The raw water Q to which chemicals have been added is discharged upward from the center of the inner cylinder 602, and after being decelerated by the baffle plate 606, reaches the water surface. At this time, the light flocs are transported by the V F The scum floats to the water surface at a speed of 1000 rpm. The scum is collected near the center of the water surface (in a circular shape) by the action of the baffle plate 606, so it can be easily scraped away. This increases the efficiency of scum removal.

[0062] Meanwhile, the separated treated water moves around the inner cylinder 602. The treated water moves over a wide area within the water tank 601 from the lower edge 602a of the inner cylinder 602 to its outer periphery. At this time, since the planar area of ​​the water tank 601 through which the treated water moves is large compared to the bottom area of ​​the inner cylinder 602, the movement speed of the treated water at the lower part of the inner cylinder 602 can be slowed down. As a result, there is more time for separation from the scum, and separation efficiency can be improved.

[0063] Thereafter, the treated water from which scum has been separated moves to the water collection port 604a of the drain pipe 604. The treated water rises from the four sides of the inner cylinder 602 through the gap between the inner wall surface of the water tank 601 and the inner cylinder 602, and is discharged from the water collection port 604a of the drain pipe 604 provided at the water surface. This allows the opening height to be low at h = 330 mm, thereby reducing both the height and the volume of the water tank 601. In this way, the miniaturization of the atmospheric pressure flotation treatment device 6 can solve various problems such as transportation restrictions, the need for on-site work, and the need to secure a large site.

[0064] Thus, the present invention Used in processing methods Table 2 shows the results of a comparison between the atmospheric pressure flotation treatment device 6 that constitutes part of the turbid water treatment facility and the conventional type of flotation treatment device shown in Figures 18 and 19. As shown in Table 2 (1), the conventional type has a slightly smaller area but a very large volume, making it uneconomical. On the other hand, as shown in Table 2 (2), the atmospheric pressure flotation treatment device 6 of the present invention has roughly the same area as the conventional treatment device, but is 59% smaller in volume, making it compact. It is an excellent treatment device that can be transported by trailer or truck.

[0065] [Table 2]

[0066] In addition, Used in processing methods The atmospheric pressure flotation treatment device 6 that constitutes the turbid water treatment facility employs an atmospheric pressure flotation treatment method that uses chemicals, so it requires a certain degree of running costs, but the chemicals electrochemically adsorb air bubbles and solids, producing highly clear treated water. Furthermore, as long as the device and equipment are made compact in shape, allowing for easy transportation of the tanks in sections by trailer or truck, and easy on-site assembly, the present invention is not limited to the above-mentioned embodiment of the invention, and can of course be modified in various ways without departing from the gist of the present invention. [Industrial Applicability]

[0067] Turbid water treatment equipment of the present invention Atmospheric pressure levitation using The treatment method can be used to treat turbid water generated not only in construction works but also in factories and various business establishments. [Explanation of symbols]

[0068] 1 Raw water tank 2 Chemical injection tank 3 Rapid Mixer 301 Cylindrical body 302 Drug injection port 303 Mixer 4 Medication machine 401 Floating Jar Tester 5 Slow agitator (reaction tube) 6 Flotation treatment device (normal pressure flotation treatment device) 601 Aquarium 602 Inner cylinder 602a Lower edge of inner cylinder 602b Upper edge of inner cylinder 603 Bottom plate 604 Drain pipe 604a Drainage pipe inlet 605 Raw water input pipe 605a Raw water inlet pipe outlet 606 Baffle Board

Claims

1. This is a turbid water treatment facility that separates turbid water generated at quarries, construction sites, factories, agricultural and fishery facilities, and waste treatment facilities into scum and purified treated water. A raw water tank (1) for storing a certain amount of raw water in order to adjust the amount of raw water (turbid water) to be treated; A cylindrical body (301) having a chemical injection port (302) for injecting a chemical into the raw water, which is disposed downstream of the raw water tank (1), and a rapid mixer (3) having a cross mixer (303) provided inside the cylindrical body (301); A tubular slow-speed mixer (5) arranged downstream of the rapid mixer (3) for chemically reacting raw water injected with a chemical agent while moving the raw water from a low position to a high position; a floating treatment device (6) having an inner tube (602) for separating raw water into scum and treated water, the opening of which faces vertically and the lower part of which is fixed away from the bottom plate (603) of the water tank (601) arranged downstream of the slow agitator (5), the nozzle (605a) of a raw water input pipe (605) being arranged inside the inner tube (602), and a drain pipe (604) having a collection port (604a) for collecting treated water being provided between the water tank (601) and the inner tube (602).

2. The turbid water treatment equipment according to claim 1, characterized in that the rapid mixer (3) is provided with the chemical injection port (302) on the upstream side of the cylindrical body (301) and the cross mixer (303) on the downstream side adjacent to the chemical injection port (302).

3. The turbid water treatment equipment described in claim 1, characterized in that the slow speed agitator (5) is made of a tubular material wound in a spiral shape multiple times, one end of the tubular material at a lower position is connected to a supply pipe from the raw water tank (1), and the other end of the tubular material at an upper position downstream is connected to a raw water input pipe (605) of the flotation treatment device (6).

4. In the floating treatment device (6), the water tank (601) has a rectangular shape in a plan view, and the inner cylinder (602) also has a rectangular shape in a plan view, 2. The turbid water treatment facility according to claim 1, wherein the outlet (605a) of the raw water input pipe (605) is disposed at a height position that is approximately half the total height of the water tank (601).

5. The turbid water treatment equipment according to claim 1, characterized in that a baffle plate (606) for deflecting the raw water in a direction perpendicular to the direction of its ejection is attached to the ejection port (605a) of the raw water inlet pipe (605) in the flotation treatment device (6).

6. The present invention relates to a normal pressure flotation treatment method for turbid water generated at quarries, construction sites, factories, agricultural and fishery facilities, and waste treatment business sites, using a turbid water treatment facility that includes a raw water tank (1) for storing turbid water (raw water) to adjust the amount of water to be treated, a rapid mixer (3) for injecting chemicals into the raw water, a slow mixer (5) for chemically reacting the raw water to which the chemicals have been injected, and a flotation treatment device (6) having an inner cylinder (602) disposed inside the tank (601) with its lower portion separated from the bottom plate (603) of the tank (601), First, a chemical is added to raw water in a rapid agitator (3), and then the raw water and the chemical are chemically reacted in a slow agitator (5); Next, the raw water that has been chemically reacted with the chemical is sprayed into the inner cylinder (602) of the flotation treatment device (6), causing the scum to float in the inner cylinder (602), and then scooped up and discharged as is. This floating treatment method using turbid water treatment equipment is characterized in that the treated water, which has been purified by separating scum from the inner cylinder (602), is allowed to settle, and this treated water is caused to move upward from the lower part of the inner cylinder (602) to between the inner cylinder (602) and the water tank (601), where it is collected so as to overflow, and then discharged to complete the treatment.

7. 7. The floating treatment method using turbid water treatment equipment as recited in claim 6, wherein, when a plurality of chemicals are added to the raw water in the rapid mixer (3), the chemicals are injected using a Smoothflow Pump which has two diaphragms arranged opposite each other to provide a continuous, non-pulsating flow.

8. A floating treatment method using turbid water treatment equipment as described in claim 6, characterized in that when determining the amount of raw water to be transported by pump from the raw water tank (1), the raw water and chemicals are placed in a floating jar tester (401) on-site, the floating time of scum is measured after a predetermined time, the amount of raw water treated per hour is calculated from the capacity of the floating treatment device (6), the flow rate of the pump (7) of the raw water tank (1) is determined, and the raw water is treated.

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