JPH07185573A - System and method for treating water - Google Patents

Abstract

PURPOSE:To improve a sterilization effect for a bacteria that exists in water to be treated in a water treating system. CONSTITUTION:The water is taken from a lake or river 100 in a channel pond 111, and added with a floculant 110 to make micro suspended matters in the water into floc in a floc forming pond 112, and it is induced to a coagulator pond 113, and subjected to sedimentation, then, it is filtered in a sand filter pond 114. Treatment up to such step is a conventional clean water treating process. In addition to that a magnetization processor 1 is arranged at the preceding stage of an ozone processor 2. The water filtered by the sand filter pond 114 is subjected to magnetization treatment by the magnetization device 1, and then is subjected to ozone treatment by blowing ozonized air from an ozone generator 3 in an ozone reaction tank 2. The water treated with ozone treatment is purified by a bio-activated carbon tower 5, and it is sterilized by a chlorine 115 in a treating water tank 116, then, it is supplied as city water via a water supply pump 117.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment system and a water treatment method used for the purification of drinking water or pool water, and the purification of recycled water of sewers.

[0002]

2. Description of the Related Art In recent years, pollution of lakes and rivers has progressed, and plankton has propagated due to eutrophication, resulting in generation of off-flavors such as musty odor and concentration of dissolved organic matter, and supply of safe and delicious water. Therefore, the introduction of advanced water purification systems using ozone and biological activated carbon is being planned or already started, especially in metropolitan areas. Here, there is little information on the reaction products formed by ozone treatment, and because of concern about their safety, the government has instructed the use of ozone for the use of activated carbon treatment. Also,
The treatment method using ozone is being studied for advanced sewage treatment for multipurpose reuse of secondary treated water from sewage treatment plants, or sterilization and decolorization of treated human waste water and dyed wastewater. In addition, the ozone method has been attracting attention for preventing biofouling that occurs in pipes such as heat exchangers and cooling water systems.

Ozone has a strong oxidizing power second to fluorine, and generally, oxidative decomposition and removal of organic matter in water, decolorization, deodorization,
Used for sterilization purposes. For example, the main purposes of ozone treatment with tap water are removal of off-flavors, decomposition and decolorization of coloring components due to humic substances, reduction of organic chlorine compound production, oxidation of soluble iron and manganese compounds, and insolubility. To improve the biodegradability of organic substances.

[0004] Although ozone alone exerts a sufficient treatment effect, it requires a treatment in a later stage, that is, treatment with biological activated carbon. In particular, when ozone reacts with organic substances, carboxylic acids, ketones, and aldehydes are often produced. Of these, aldehydes have been pointed out to be harmful, and it is essential to install activated carbon treatment in advanced water treatment of water supply.

On the other hand, when a magnetic field is applied to water, it is said that water exhibits unique physical properties, and it has been the subject of many scholars' research and has been a topic for a while. Although this is a phenomenon for which physicochemical confirmation has not been obtained, many application examples have been reported, practical applications or numerous patents have been filed, and various magnetization processors are commercially available. As typical application examples, 1) application examples to magnetically treated water pools (JP-A-52-71854 and 57-29227), 2) application examples to biological systems such as biotechnology and aquaculture (special features JP-A-64-56189, JP-A-2-39887, JP-A1-299
688, JP-A-1-34629, JP-A 1-262988), 3) Application example for magnetized concrete, 4) Application example for scale prevention by magnetized water (JP-A-1-184291) 5) Examples of application of magnetized water to prevention of red rust, 6) Examples of application to fuel oil magnetization, and so on. In particular, magnetized water is said to be effective in preventing scale, and there are many reports of application examples to magnetic processing devices for scale prevention.

A cooling water purifying apparatus disclosed in Japanese Patent Application Laid-Open No. 1-262987 is one that utilizes both the magnetization treatment and the ozone treatment. This is to circulate a part of the circulating cooling water of the cooling tower for filtration and ozone treatment, and to magnetically treat the other circulating water, and then to join the ozone-treated water with the magnetically treated water. And the magnetization processing is performed in parallel. In addition, there are examples of research presentations on treatment methods using ozone and ultraviolet rays, electron beams, and catalysts (for example, Chemical Engineering, Vol.55, No.9, 1991).

[0007]

However, in the above-mentioned conventional technique, the ozone treatment and the magnetization treatment are performed in parallel, so that the sterilizing effect is not sufficient. That is,
It has been reported that when a magnetic field is applied to the treated water, the behavior of live bacteria in the water is inactivated and the growth of live bacteria is suppressed. You can not expect a good bactericidal effect. Further, there is no theoretical background for confirming the effect of the magnetization process, and it is difficult to guarantee a sufficient effect.

[0008] An object of the present invention is to provide a water treatment system and a water treatment method capable of sufficiently improving the bactericidal effect on bacteria existing in water to be treated.

[0009]

[Means for Solving the Problems] To achieve the above object,
The present invention relates to a water treatment system provided with an ozone treatment device for sterilizing water to be treated with ozone, wherein a magnetizing treatment device for giving magnetic energy to bacteria present in the water to be treated is treated water. Along the flow of 1., the ozone treatment apparatus is arranged at one of the front stage and the rear stage, or both at the front stage and the rear stage.

In the water treatment system having the above structure, the present invention provides a magnetizing treatment device for applying magnetic energy to bacteria existing in the water to be treated, which is an ozone treatment device along the flow of the water to be treated. While arranging it in the front stage of
A part of the water to be treated which has been magnetized by the magnetizing device is guided to the ozone treating device.

In the water treatment system having the above structure, the present invention further comprises a magnetizing treatment device for applying magnetic energy to bacteria existing in the water to be treated, which is an ozone treatment device along the flow of the water to be treated. It is placed in the latter part of the
A part of the water to be treated that has been sterilized by the ozone treatment device is guided to the magnetization treatment device.

Further, the present invention provides the water treatment system having the above-mentioned structure, further comprising a magnetizing treatment device for giving magnetic energy to bacteria existing in the water to be treated,
A part of the water to be treated that has been sterilized by the ozone treatment device is guided to the magnetization treatment device, and the treatment target water that has been magnetized by the magnetization treatment device is returned to the previous stage side of the ozone treatment device.

Further, according to the present invention, any one of the above-mentioned water treatment systems is used in a sewage secondary treated water advanced treatment system in which a part of sewage is treated as sewage or in a pool water purification system for purifying pool water. Is.

Furthermore, the present invention is a water treatment method for sterilizing water to be treated with ozone, wherein the sterilizing treatment is a magnetizing treatment for imparting magnetic energy to bacteria present in the water to be treated. Before or after, or both before and after.

[0015]

The present invention focuses on the synergistic effect of the oxidizing power of ozone and magnetic energy. Although there is no one that confirms the effect of magnetizing treatment, from magnetohydrodynamics (MHD power generation) based on Faraday's theory, when water passes through a magnetic field at a certain flow velocity, magnetic energy shock to live bacteria in the water Is expected to occur.
In addition to this, if it is oxidized with strong ozone, the bactericidal effect is great.

As a result of an experimental study with the secondary treated sewage water,
It was confirmed that the bactericidal effect of ozone was increased by the treatment with magnetization and ozone in series. Furthermore, as another effect, the same experiment was performed for the cohesiveness due to magnetization,
A new finding was obtained that the ζ potential of a suspension in water (addition of kaolin) changes. That is, since soluble iron ions and salts in water are oxidized by ozone to become insoluble compounds, which are aggregated and become a precipitate when passing through a magnetic field, it can be expected that removal by post-treatment will be easy.

The present invention has been made based on the above experimental results, and by performing magnetization and ozone treatment in series, it is possible to expect a great improvement in the sterilization effect by ozone and other effects.

If a part of the water to be treated that has been sterilized by the ozone treatment device is guided to the magnetization treatment device, or a part of the water to be treated that has been magnetized by the magnetization treatment device is introduced to the ozone treatment device. The processing amount by the magnetization processing device or the processing amount by the ozone treatment can be reduced. When returning part of the water to be treated that has been sterilized by the ozone treatment device to the previous stage of the ozone treatment device after magnetization treatment with the magnetization treatment device,
Similarly, the amount of processing by the magnetization processing device can be reduced.

[0019]

EXAMPLES The following experiments were conducted in order to demonstrate the effects of the present invention. By combining magnetization and ozone treatment, paying particular attention to the decomposition and removal performance of live bacteria, an experiment was conducted using secondary treated sewage water. The experimental method is shown in FIG. In a reaction separable flask 2 (5 liters in volume), a suspension of ozone (S
In order to reduce the influence on S), 4 liters of sewage secondary treated water subjected to sand filtration was tested. Ozone generator 3 is 0.8 g / Nm ³ -Ozonized air 1 liter / min (0.8
(mgO ₃ / liter air) was blown into the flask 2 from the ceramic air diffuser at the bottom of the flask 2 via the flow meter 23.
It was exhausted as exhaust ozone gas from the upper part. Gas phase generation-Exhaust ozone concentration measurement was performed by switching the pipes, and both the exhaust ozone concentration and the dissolved ozone concentration were measured by a diaphragm-type polarographic electrode-type ozone concentration meter for gas phase 3a and dissolved ozone concentration 3b.

The sewage secondary treated water was circulated at a rate of 200 ml / min by a pump, and a commercially available magnetization treatment device 1 was arranged on the discharge side of the pump 7 to make it a batch treatment type. In the experiment, the sewage secondary treated water was circulated by the pump 7 while magnetizing, and the ozonized air was circulated to the ozone concentration meter by the three-way switching valve 8 and switched when the generated ozone concentration became constant. I blew from. Sampling was carried out at appropriate times, and the bactericidal effect was evaluated by the number of remaining E. coli. A decioxycholate agar medium was used for culturing Escherichia coli.
In the figure, 20 and 21 are cells, and 22 is a switching valve.

The experimental results are shown in FIG. Experimental results of ozone alone and magnetization / ozone treatment in the coexistence of organic matter (COD concentration 10 ppm) are shown.
(CT value). The sewage secondary treated water contains approximately 10 ³ E. coli / ml. Although the coliform group decreases exponentially with the increase of CT value,
The slope is steeper when magnetized and ozone treated. further,
As a remarkable effect, when the treated water treated with ozone alone is left in the flask for one day and night, the E. coli re-proliferates, but the treated water for magnetization and ozone does not change even if left for one day and becomes undetectable. This is because the survival energy of bacteria is reduced by the magnetic energy shock when passing through the magnetization process and is decomposed by strong ozone oxidation. It is supposed to do.

In this case, it is important to perform a pair of ozone treatment and magnetizing treatment. This is an effect that cannot be obtained by the parallel processing of ozone treatment and magnetization treatment according to a conventional example (for example, Japanese Patent Laid-Open No. 1-262987).

Further, a simple study was made on the cohesiveness as another effect of the magnetization treatment by the same experimental apparatus. Stop ozone blowing, add 100 ppm of sodium sulfate (Na ₂ SO ₄ ) to distilled water as test water, suspend 200 ppm of kaolin (average particle size 50 μm) as suspended particles, and circulate while coagulating It was investigated. The result is shown in FIG. Cohesiveness is 100 in the settling tube at any circulation time.
Turbidity was measured by sampling milliliters of water and sampling only 10 milliliters from the water surface for each standing time. The difference in turbidity between untreated and magnetized is clear. Although the reason for the improvement of cohesiveness by the magnetization treatment is unknown, one of them was that the ζ potential of the kaolin particles was changed. The result is shown in FIG. Magnetization was carried out by the above-mentioned experimental apparatus, and sampling was carried out at each circulation time where it was circulated in the flask, and analyzed by a meter meter. Usually, fine particles in water have an electric double layer, and are difficult to settle due to Brownian motion at a negative potential. Although the initial ζ potential of kaolin particles is −30 to 40 mV, a new finding was obtained that the ζ potential turns to + when circulating while magnetizing. This means the same effect as adding a coagulant such as PAC. Therefore, soluble ions or salts are oxidized by ozone and precipitated as an insoluble compound, which is magnetized and agglomerated to facilitate separation. This is due to the effect of the serial treatment of ozone and magnetization.

Next, an embodiment of the present invention will be described below with reference to the drawings based on the above experimental results. FIG. 1 shows a processing flow of an advanced water purification system which is an embodiment of the present invention. The coagulant 11
0 is added to flocculate fine suspended matter in water in the floc formation pond 112. This is introduced into the coagulation sedimentation tank 113 to perform sedimentation separation, and is filtered in the sand filtration tank 114. Up to this point, it is the same as the current water treatment process.

In addition to these, in the present embodiment, the filtered water is treated by the magnetizing treatment apparatus 1 and then, in the ozone reaction tank 2, ozonized air is blown from the ozone generator 3 so that the ozone gives off a strange odor. Is subjected to oxidative decomposition treatment and purified in the biological activated carbon tower 5. Then, the purified treated water is sterilized by the addition of chlorine 115 in the treated water tank 116, and is supplied as tap water through the water supply pump 117. Further, the exhaust ozone after being supplied to the oxidative decomposition is processed by the exhaust ozone decomposition processing device 4 and exhausted.

In FIG. 1, the magnetization processing apparatus 1 is arranged in the front stage of the ozone reaction tank 2. However, the magnetization processing apparatus 1 may be arranged in the rear stage of the ozone reaction tank 2 or in both the front and rear stages.

FIG. 7 is a main part of the magnetization processing apparatus and shows the details of the permanent magnet type magnetization processing apparatus. FIG. 8 shows the principle of magnetization processing. An iron outer cylinder 11 is provided centering on the cylindrical permanent magnet 10, and the magnetic force lines 10m act perpendicularly to the axial direction. Magnetic field strength is 600-2000
Gauss is suitable. The water flow 14 of the treated water is distributed and agitated from the pipe 13, passes through the magnetic line of force 10 m between the magnet and the iron outer cylinder, and is magnetized. This type is common in commercial products and was used in the above experiment.

9 and 10 show the case of an electromagnet type magnetization processing device. Lines of magnetic force are generated in the pipe 11 of the flow path by the electromagnet 10a. FIG. 10 shows an example of a magnetizing process in which the stainless wool 15 is filled in the pipe 11 and the principle of high gradient magnetic separation (HGMS) is applied, or a sand layer filler containing mineral components such as Ca and K is provided. , Also effective in removing the suspended fine particles that have flowed out. In this case, the magnetic field line strength is suitably 1000 to 5000 gauss. In the figure, 10b shows a coil of the electromagnet 10a.

FIG. 2 shows a modification of the water treatment system described above. In this modification, a part of the treated water treated by the magnetization treatment device 1 is branched and guided to the ozone reaction tank 2 and further treated by the biological activated carbon tower 5. Then, after being treated in the biological activated carbon tower 5, the treated water is combined with the as-magnetized water (water not subjected to ozone treatment by the ozone treatment device 2) and sterilized with chlorine in the same manner as described above, and then the water pump 117.
To supply water. According to this modification, the amount of treated water in the ozone reaction tank 2 and the biological activated carbon tower 5 can be reduced. In addition, in FIG. 2, the amount of treated water can be reduced by exchanging the position of the magnetizing treatment device 1 and the position of the ozone treating device 2 and magnetizing a part of the treated water subjected to the ozone treatment.

FIG. 3 is also a modification similar to FIG. In this modification, a part of the treated water magnetized by the magnetizing device 1 is branched and ozone-treated by the ozone treating device 2, then further treated by the magnetizing treating device 1, and then activated carbon is treated by the biological activated carbon tank. From the above, the magnetized water is merged with the treated water that has been magnetized by the magnetizing device 1, sterilized with chlorine, and water is supplied.

FIG. 4 is also a modification, but this modification is shown in FIG.
And slightly different from that of FIG. That is, in this modification, a part of the treated water magnetized by the magnetizing device 1 is branched and ozone-treated in the ozone reaction tank 2, and the ozone-treated water is returned to the previous stage of the magnetizing device 1 and circulated. However, after that, the biological activated carbon tower 5 is used for treatment.

Next, FIG. 5 shows an embodiment of an advanced treatment system for sewage secondary treatment water which is used for multiple purposes such as car wash, toilet and water sprinkling between the clean water and the sewage by treating the sewage secondary treatment water. Show. The inflow sewage 200 flows into the settling basin 210, passes from the first settling basin 211 through the aeration tank 212, and then to the final settling basin 213.
In chlorinated sewage, the effluent is discharged from the chlorine mixing basin 214, but all or part of the effluent 215a is filtered by the sand filter tower 216, treated by the magnetization treatment device 1 and ozone-treated in the ozone reaction tank 2. , Used as medium water 220.
In the case of sewage secondary treated water, it is considered that foaming occurs in the ozone reaction tower 2. Therefore, waste ozone is processed by the waste ozone decomposition processing device 4 and discharged through the defoaming tower 2a. In addition, 21
2 is treated sewage water.

FIG. 6 shows an embodiment of a pool water purification system. The water in the pool 310 passes through the hair collector 311 and is sent to the filtration tower 313 by the circulation pump 312, processed by the magnetization processing device 1 and circulated to the pool as the magnetization processed water 314. 314a is branched to take in the ozonized air from the ozone generator 3 in the ejector 6 and is treated in the ozone reaction tower 2, and the treated water is guided to the suction side of the circulation pump 312 and circulated. Exhaust ozone in the ozone reaction tower 2 is processed by the exhaust ozone decomposition processing device 4 and exhausted.

[0034]

As described above, the present invention has the following effects.

1) Water treatment system The synergistic effect of magnetization and ozone treatment improves the purification performance in the biological activated carbon tower and increases the sterilization effect, so that the amount of chlorine added can be reduced.

By distributing a part of the magnetized water to the ozone treatment, the amount of the ozone treated water can be reduced, and the ozone generator can be downsized and the power consumption can be reduced.

Since soluble iron ions are strongly oxidized by ozone and converted into insoluble compounds, it is C
Even if agglomerates are formed as nucleation buds of salt precipitation such as a, the agglomerates can be easily removed, water quality hardness can be expected to be reduced, and at the same time, scale prevention is also effective.

"Delicious water" as magnetic water can be expected.

The use of the magnetization processing device having a built-in permanent magnet does not require new electric power and does not increase the cost.

2) Sewage secondary treated water advanced treatment system By sterilization and decolorization by magnetizing-ozone treatment, good quality sewage can be obtained and its application as reused water can be expanded.

The blowing component is simultaneously removed by blowing ozonized air.

3) Pool Water Purification System Since the magnetized-ozone treated water circulates, the bactericidal effect is sustained and there is no dirt adhesion which seems to be algae that is generated on the pool's water surface.

The ozone treatment effect increases the transparency of the water in the pool.

The amount of chlorine added for sterilization can be reduced, and the smell of chlorine is small, which improves comfort during swimming.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a water treatment system of the present invention.

FIG. 2 is a diagram showing a modification of FIG.

FIG. 3 is a diagram showing another modified example of FIG.

FIG. 4 is a diagram showing still another modified example of FIG.

FIG. 5 is an overall configuration diagram of a sewage secondary treated water advanced treatment system to which the water treatment system of the present invention is applied.

FIG. 6 is an overall configuration diagram of a pool water purification treatment system to which the water treatment system of the present invention is applied.

FIG. 7 is a detailed view of a main part of a permanent magnet type magnetization processing device.

FIG. 8 is a diagram showing a principle of magnetization processing.

FIG. 9 is a detailed view of a main part of an electromagnet type magnetization processing device.

FIG. 10 is a detailed view of a main part of an electromagnet type magnetization processing device having another configuration.

FIG. 11 is a diagram showing a basic experiment flow of magnetization-ozone treatment.

FIG. 12 is a diagram showing a bactericidal effect by magnetization-ozone treatment.

FIG. 13 is a diagram showing the cohesiveness of suspended fine particles due to a magnetization treatment.

FIG. 14 is a diagram showing a change in ζ potential of suspended fine particles due to a magnetization process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetization processing apparatus 2 Ozone reaction tank or reaction tower 3 Ozone generator 4 Waste ozone decomposition processing apparatus 5 Bioactive carbon tower 10 Permanent magnet 10a Electromagnet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location C02F 1/50 531 R 540 A 560 G (72) Inventor Kenji Baba 7-chome Omika-cho, Hitachi City, Ibaraki Prefecture No. 1-1 Hitachi Ltd., Hitachi Research Laboratory (72) Inventor Minoru Suzuki 1-1-1 Kokubuncho, Hitachi City, Ibaraki Prefecture Hitachi Ltd. Kokubun Plant

Claims (11)

[Claims] 1. A water treatment system comprising an ozone treatment device for sterilizing water to be treated with ozone, wherein a magnetization treatment device for giving magnetic energy to bacteria present in the water to be treated is treated. A water treatment system characterized in that the water treatment system is arranged at one of a front stage and a rear stage of the ozone treatment device, or at both a front stage and a rear stage along the flow of water. 2. The water treatment system according to claim 1, wherein the magnetization treatment device is sterilized by the ozone treatment device so that soluble ions and salts contained in the water to be treated are dissolved. A water treatment system characterized in that, when an organic substance is oxidatively decomposed into an insoluble compound and deposited as a suspension, the water to be treated is subjected to a magnetizing treatment to aggregate the insoluble compound and the suspension. 3. A water treatment system provided with an ozone treatment device for sterilizing water to be treated with ozone, wherein a magnetizing treatment device for giving magnetic energy to bacteria present in the water to be treated is treated. A water treatment system characterized in that the water treatment system is arranged upstream of the ozone treatment device along the flow of water and guides a part of the water to be treated which has been magnetized by the magnetization treatment device to the ozone treatment device. 4. A water treatment system comprising an ozone treatment device for sterilizing water to be treated with ozone, wherein a magnetizing treatment device for giving magnetic energy to bacteria existing in the water to be treated is treated. A water treatment system characterized in that the water treatment system is arranged downstream of the ozone treatment device along a flow of water and guides a part of the water to be treated that has been sterilized by the ozone treatment device to the magnetization treatment device. 5. A water treatment system comprising an ozone treatment device for sterilizing water to be treated with ozone, wherein a magnetizing treatment device for giving magnetic energy to bacteria present in the water to be treated is provided. A water treatment system characterized in that a part of the water to be treated that has been sterilized by the ozone treatment device is guided to a magnetization treatment device, and the treatment water that has been magnetized by the magnetization treatment device is returned to the front side of the ozone treatment device. . 6. The water treatment system according to claim 1, wherein the water to be treated that has been sterilized by the ozone treatment device and magnetized by the magnetization treatment device is biological activated carbon later. A water treatment system characterized by being treated. 7. The water treatment system according to any one of claims 1 to 3, wherein the magnetization treatment device applies magnetic lines of force to the water to be treated from outside, inside or both sides of the flow path. A water treatment system comprising means. 8. The water treatment system according to claim 7, wherein the magnetic force generating means comprises an electromagnet or a permanent magnet,
The magnetic field line strength is set to 100 to 100,000 Gauss. 9. An advanced treatment system for sewage secondary treated water, which uses the water treatment system according to any one of claims 1 to 8 as part of sewage. 10. A pool water purification system for purifying pool water using the water treatment system according to claim 1. 11. A water treatment method for sterilizing water to be treated with ozone, wherein a magnetizing treatment for imparting magnetic energy to bacteria present in the water to be treated is performed before or after the sterilizing treatment. A water treatment method characterized in that it is carried out either one way or both before and after.