JP2003012410A - Antiseptic solution for waste water and method and apparatus for disinfecting waste water by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a novel disinfectant capable of efficiently and inexpensively disinfecting untreated sewage in rainy weather containing bacteria such as E. coli and the like discharged to public waters from sewage plants, pumping stations and rain water outlets, especially overflows in the sewage plants. SOLUTION: This disinfectant contains a halogenated glyoxime. Preferably, the disinfectant contains a bromine-based compound in addition to the halogenated glyoxime. A method and equipment for disinfecting waste water by using the disinfectant are also provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to the field of wastewater treatment, particularly sewage treatment, and more specifically, it is used for disinfection of sewage discharged from a sewage treatment plant, a pump station, a rainwater outlet into a public water area. The present invention relates to a disinfectant that can be used and a method for disinfecting sewage using the disinfectant.

[0002]

2. Description of the Related Art A sewage treatment plant is a facility for detoxifying sewage discharged from homes and factories and discharging it into public water areas. The sewage mixed with rainwater (hereinafter referred to as sewage in rainy weather) is discharged from the pump station and rainwater spout to the public water area in a few tens of seconds to a few minutes without treatment. In this case, coarse suspended matter and SS (suspended substance: suspended matter) are discharged to public water bodies as they are, which often causes an aesthetic problem. Even at sewage treatment plants, if the inflowing sewage significantly exceeds the treatment capacity, some of the sewage in rainy weather may be discharged without treatment. In this case, since disinfection of bacteria is not carried out, coliform bacteria may be detected that greatly exceed the emission control value (3000 CFU / mL or less) specified by the Water Pollution Control Law. These are the phenomena especially seen in the combined sewer system, but even in the divided sewer system, soil coliform bacteria and coarse suspended solids flow into the sewer system. The same problem as the sewer system occurred.

For disinfection at a sewage treatment plant, see "Sewerage Facility Planning".
・ Design guidelines and explanations ”(Published by Japan Sewer Association, Ministry of Construction
According to the Bureau of Sewerage, October 1994), hypochlorite
Sodium oleate, liquefied chlorine, chlorinated isocyanuric acid, next
Mix them using a chlorine agent such as calcium chlorite
Large intestine by contact with sewage in the pond for more than 15 minutes
A method of disinfecting a bacterial group is shown. In addition, "sewer
Design drawings, design guidelines and explanations "are based on ozone and ultraviolet rays.
Disinfection is also described. Furthermore, tens of thousands of meters ³Storage of
A pond is provided to temporarily store sewage in case of rain, and rainfall exceeding the storage amount
If overflow occurs depending on the amount, use the above chlorine agent.
A method of disinfecting is also proposed.

[0004]

The above-mentioned chlorine agents such as sodium hypochlorite, liquefied chlorine, chlorinated isocyanuric acid and calcium hypochlorite are sufficiently mixed with sewage in a mixing pond or the like ( It is effective for disinfecting coliform bacteria if they can be contacted (for example, 15 minutes or more). However, when the rainfall intensity is large and it is discharged to public water areas in a short time like rainwater sewage, the contact time between the chlorine agent and the sewage cannot be taken sufficiently, so the discharge specified by the Water Pollution Control Act is not possible. It cannot be less than the standard value of coliforms in water. In addition, since the sewage in rainy weather has a large content of ammonia nitrogen, the added chlorine agent easily reacts with ammonia nitrogen to form chloramine having a low disinfection effect and high persistence. For this reason, not only is disinfection of coliform bacteria not sufficiently performed, but the chloramine formed remains as bound residual chlorine in public water bodies for a long time and adversely affects the environment. Not preferred to use.

The above-mentioned "Sewerage Facility Planning / Design Guideline and Explanation" also describes disinfection with ozone or ultraviolet rays. When using ozone, it is necessary to install equipment that supplies the amount of ozone that can be disinfected to the maximum expected amount of overflow water. Overflow of sewage during rainy weather is usually 20 to 50 times a year, and otherwise normal treatment is possible. However, in order to disinfect sewage in rainy weather of tens of thousands of m ³ per hour to the standard value stipulated by the Water Pollution Control Law, it is necessary to install a huge ozone injection facility, and when considering cost effectiveness, Not a wise way. Further, after ozone injection, it is necessary to neutralize ozone in the gas phase, but it is difficult to apply it to sewage with many underdrains, and there is a concern that equipment costs will increase due to installation of a waste ozone treatment device.

[0006] In addition, a basin of tens of thousands of m ³ is provided to temporarily store sewage in the case of rain, and when overflow occurs due to the amount of rainfall exceeding the amount stored, disinfection is performed using the above chlorine-based disinfectant. Methods have also been proposed. However, there are often no places to install new reservoirs in existing sewage treatment plants,
Not realistic. Further, when disinfection is carried out using a chlorine agent, the discharge of residual chlorine into the same environment as described above remains a serious problem, which is not preferable.

[0007]

Means for Solving the Problems The present invention solves the above-mentioned problems and provides an untreated untreated material containing bacteria such as coliform bacteria discharged from a sewage treatment plant, a pump station, a rainwater outlet to a public water area. It is an object of the present invention to provide a new disinfectant capable of disinfecting sewage in rainy weather efficiently and inexpensively.

As a means for solving the above problems, the present invention provides a drainage disinfectant containing a halogenated glyoxime. Furthermore, the present invention also relates to a method of disinfecting wastewater using such a disinfectant solution.

[0009]

DETAILED DESCRIPTION OF THE INVENTION Various embodiments of the present invention will be described below. The disinfectant according to the present invention is characterized by containing a halogenated glyoxime. Halogenated glyoximes are characterized by being able to disinfect bacteria such as coliform bacteria in a few tens of seconds to a few minutes. In addition, since halogenated glyoxime becomes oxahydroxamic acid, which has almost no toxicity in a short time of about several minutes, it is suitable as a disinfectant for wastewater discharged into public water bodies, particularly for sewage in rainy weather. Further, as compared with sodium hypochlorite which has been generally used as a disinfectant for drainage, there is no problem that the disinfection effect is lowered due to chloramine production, and no problem of residual chlorine occurs.
When using hypochlorite as a disinfectant, it is necessary to bring it into contact with sewage in a mixing pond for 15 minutes or more, as described above, because hypochlorite produces chloramine. This is because the disinfection activity is reduced. On the other hand, in the present invention, since the halogenated glyoxime is used as a disinfectant, it does not produce chloramine and does not lose the active ingredient, so that not only can bacteria be disinfected in a short time, but chloramine and the like It is also possible to prevent residual chlorine from being released into public water bodies. Further, hypochlorite has a feature that it reacts with organic substances in sewage to produce carcinogenic trihalomethane, but halogenated glyoxime does not produce trihalomethane. Examples of halogenated glyoximes that can be used in the present invention include dichloroglyoxime, dibromoglyoxime,
Examples thereof include bromochloroglyoxime.

In the prior art, papermaking process water in the paper and pulp industry, cooling water and washing water for various industries, heavy oil sludge, metalworking oil, fiber oil, paint, antifouling paint, paper coating liquid, latex. It has been proposed to use a composition containing a specific organic sulfur compound, an organic bromine compound and an oxime compound as an essential ingredient as an antiseptic or bacteriostatic / bacteriostatic agent in industrial applications such as starch. The bactericides used are used for the industrial purposes as described above, and their application fields are completely different from the disinfection of drainage, especially sewage in rainy weather, which is the object of the present invention. Also,
In the proposed fungicides, not only organic bromine compounds and oxime compounds but also 4,5-dichloro-
1,2-Dithiol-3-one is an essential component. The present invention does not require this organochlorine compound,
The inventors have found that a halogenated glyoxime can be used to obtain a disinfectant effective for disinfection of wastewater, especially sewage in rainy weather.

In the present invention, the halogenated glyoxime can be transported or used in the form of being dissolved in a diethylene glycol monomethyl ether solution. As the dissolution concentration in this case, any concentration can be selected, but a concentration in the range of 1 to 50 wt% is particularly preferable. This is because if the concentration is less than 1 wt%, the transportation cost becomes high, which is not preferable, and if the concentration exceeds 50 wt%, it is difficult to manufacture.

[0012] The addition rate of halogenated glyoxime to the wastewater is determined within several tens of seconds to several minutes so that bacteria such as coliform bacteria in the wastewater fall below the value (3000 CFU / mL) specified by the Water Pollution Control Law. . The suitable addition rate depends on the water quality of the wastewater to be treated, especially turbidity and BOD, and
Although it cannot be clearly specified because it depends on the discharge or overflow time, it is preferable that the halogenated glyoxime concentration is in the range of 0.5 to 100 mg / L. A more preferable range of the addition rate is 1 to 40 mg / L,
1 to 20 mg / L is more preferable. If the addition rate of the disinfectant according to the present invention is less than 0.5 mg / L, the disinfecting effect of rainwater sewage can hardly be expected, and if it exceeds 100 mg / L, excess halogenated glyoxime is released to public water bodies. Therefore, it is not preferable because it adversely affects the environment.

Further, the disinfectant according to the present invention may contain a bromine compound in addition to the halogenated glyoxime. When a brominated compound is further added, the disinfecting effect can be further enhanced as compared with the case where a halogenated glyoxime is added alone. Although the halogenated glyoxime alone has a disinfecting effect, it is preferable to use a brominated compound together in order to suppress the generation of resistant bacteria and stably disinfect bacteria such as coliform bacteria for a long period of time. As the bromine-based compound that can be used in the present invention for this purpose,
2,2-dibromo-3-nitrilopropionamide,
1,2-bis (bromoacetoxy) ethane, 1,4-bis (bromoacetoxy) butene, 1-bromo-3-chloro-5,5-dimethylhydantoin, 1,3-dibromo-5,5-dimethylhydantoin, It is possible to use at least one or more of brominated compounds such as trichloroisocyanuric acid, dichloroisocyanuric acid, tribromoisocyanuric acid, dibromochloroisocyanuric acid, bromodichloroisocyanuric acid, dibromoisocyanuric acid, bromochloroisocyanuric acid, and hypobromite. it can. Disinfectant according to the present invention, especially when used for disinfecting sewage in rainy weather, it is necessary to complete the disinfection in a short time and discharge after the disinfectant components are detoxified, these bromine-based compounds, Since the fish toxicity is low and the decomposition rate is high, the influence on the environment is small and it is suitable for use as one component of the disinfectant according to the present invention. In the disinfectant according to the preferred embodiment of the present invention, the mixing ratio of the brominated compound to the halogenated glyoxime is preferably in the range of 0.05 to 5 by weight.
When the ratio of brominated compounds is less than 0.05, the meaning to enhance the disinfecting effect by mixing brominated compounds is small, and when the ratio is greater than 5, the disinfecting effect of the main ingredient, halogenated glyoxime, is fully exerted. It is not preferable because it is not done.

The disinfectant according to the present invention can be used for disinfecting wastewater such as sewage, and in particular, for disinfecting sewage in rainy weather, especially sewage including rainwater removed from pump stations and rainwater outlets. It is particularly suitable. These rainwater sewage,
Since disinfection with conventional hypochlorite was not possible for a short period of time, it is currently discharged untreated to rivers or the sea, but according to the disinfectant of the present invention, Such sewage in rainy weather can be disinfected in a short time, which greatly contributes to environmental problems. Incidentally, the sewage containing the rainwater that is removed from the pump station or the rainwater spout is usually discharged untreated, but in the present invention, the untreated rainwater sewage can be disinfected as it is. Alternatively, it is also possible to perform a pretreatment such as removal of contaminants, SS, BOD, etc. in advance and then disinfect. If SS or BOD of sewage in rainy weather is removed, halogenated glyoxime is not consumed for the oxidation thereof, which is advantageous in that the addition rate of halogenated glyoxime can be reduced.

The disinfectant according to the present invention is also particularly suitable for disinfecting sewage containing rainwater discharged from a sewage treatment plant and containing untreated and / or simply treated rainwater. When there is a large amount of rainwater sewage flowing into the sewage treatment plant, these rainwater sewage may be untreated and / or subjected to a simple treatment before being discharged. In some cases, the water quality standard value was significantly exceeded, but the disinfectant according to the present invention disinfects such rainy sewage in a short time. In this case as well, in the same manner as described above, the sewage in the case of rain may be subjected to the contaminant, SS, and BOD removal treatment and then subjected to the disinfection treatment according to the present invention.

However, the sewage that has been subjected to the normal treatment at the sewage treatment plant, that is, the first settling basin, the biological treatment, the final settling basin, and the disinfection treatment, satisfies the water quality standard value stipulated by the Water Pollution Control Law. It is not necessary to carry out the disinfection treatment according to the invention.

According to the present invention, it is possible to preferably disinfect sewage including rainwater generated from the combined sewer system and the split sewer system. In the combined sewer system or the segregated sewer system, the faecal or soil-type coliform bacteria inflows in the case of rain, and when the inflowing water amount is large, the structure is such that it is discharged without treatment. Such disinfection treatment is extremely preferable because bacteria such as coliform bacteria in sewage can be disinfected in a short time. On the other hand, simple septic tanks and combined septic tanks can have a long residence time, and
Since the microbial treatment is used in combination, the use of the disinfectant kills the microorganisms and reduces the initial effect of the septic tank. Therefore, it is not preferable to use the disinfectant of the present invention.

The present invention also provides an apparatus for disinfecting drainage using the above-described disinfectant. That is,
Another aspect of the present invention relates to an apparatus for disinfecting wastewater, comprising an apparatus for supplying halogenated glyoxime to the wastewater. The invention also relates to a device as described above, further comprising a device for supplying the bromine-based compound to the wastewater. Furthermore, the present invention is an apparatus for disinfecting wastewater, which is an apparatus for preparing a disinfecting solution by mixing a halogenated glyoxime and a bromine compound;
It also relates to a device for disinfecting wastewater, comprising a device for supplying the prepared disinfectant solution to the wastewater.

A specific example of the apparatus for disinfecting waste water according to the present invention will be described below with reference to the drawings. Figure 1
FIG. 1 is a schematic diagram illustrating an embodiment of an apparatus according to the present invention. In FIG. 1, 1 is a halogenated glyoxime storage tank; 2 is a brominated compound storage tank; 3 is a brominated compound dissolution apparatus; 4 is a halogenated glyoxime / bromine compound mixing tank; 5 is a mixed solution supply pump; 6 is a turbidimeter And / or SS meter; 7 is control system; 11 is glyoxime halide transfer pipe; 1
2 is a brominated compound transfer pipe; 13 is a halogenated glyoxime supply pipe; 14 is a mixed liquid supply pipe; 15 is a brominated compound supply pipe; 21 is an inflow pipe; 22 is a shielding pipe;
Is a discharge pipe; 31 is an inflow side water level at the time of maximum treatment; 32 is an emergency overflow water level; 40 is an overflow overflow sewage;

The sewage flowing from the sewage inflow pipe 21 is normally sent to the sewage treatment plant through the interceptor pipe 22.
It is rendered harmless and released to public water bodies. However, when the amount of rainfall increases and the sewage flowing through the sewage inflow pipe 21 exceeds the maximum inflow water level 31, the overflow water 40 is discharged.

In the apparatus shown in FIG. 1, the glyoxime halide is transferred from the storage tank 1 to the mixing tank 4 through the transfer pipe 11. Further, the bromine-based compound is transferred from the storage tank 2 to the mixing tank 4 through the transfer pipe 12. When the brominated compound used is a solid, it is first dissolved in the dissolution apparatus 3 and then transferred to the mixing tank 4. The disinfecting solution according to the present invention formed by mixing the halogenated glyoxime and the bromine compound in the mixing tank 4 is supplied into the sewage by the supply pump 5 through the supply pipe 14. Further, the halogenated glyoxime can be separately supplied into the sewage through the supply pipe 13 and the bromine-based compound through the supply pipe 15. In this case, the sewage may be supplied first with the brominated compound as shown in FIG. 1 or with the halogenated glyoxime first. When a halogenated glyoxime is used alone as a disinfectant, the halogenated glyoxime can be directly supplied from the storage tank 1 to the sewage through the supply pipe 13 without using the brominated compound storage tank 2 and the mixing tank 4. it can.

Wastewater supplied with the disinfectant according to the present invention and subjected to disinfection is discharged into the public water area through the discharge pipe 23. The contact time between the disinfectant according to the present invention and the wastewater to be treated is preferably 10 seconds to 20 minutes, and 10 seconds to 1
0 minutes is more preferred.

Further, the disinfecting apparatus according to the present invention can be interlocked with an apparatus for measuring the quality of waste water. In FIG. 1, 6 is an apparatus for measuring turbidity and / or SS of waste water. Rainwater sewage is a type of rainwater that can be released.
At first, the turbidity and S
S becomes higher, and then turbidity and SS gradually decrease.
Therefore, this information can be read by the measuring device 6 and the control system 7 can supply the sewage 40 with the disinfecting liquid injection rate of an amount corresponding to the turbidity and / or SS of the sewage in rainy weather. The correlation between the turbidity and / or SS of the wastewater and the disinfecting effect (the optimum supply amount of the disinfecting liquid) can be obtained in advance by a preliminary test, and the accuracy can be increased as the number of tests is increased.

[0024]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to efficiently disinfect coliform bacteria in sewage during rainy weather, which has been conventionally discharged into public water bodies without treatment, and is hypochlorite which is a general-purpose disinfectant. Unlike sodium acidate, it does not generate residual chlorine such as chloramine, so it can reduce the impact on the aquatic organisms at the discharge destination and does not cause environmental problems.

[0025]

EXAMPLES The following examples illustrate more specific aspects of the present invention, but the present invention is not limited to the following examples.

Examples 1 to 6 A disinfection test for coliform bacteria according to the present invention was carried out by using the rainwater sewage discharged from the pump station at the time of rainfall of 5 mm / hour as treated water. As a disinfectant, dichloroglyoxime was added to sewage in rainy weather so as to have various concentrations. Table 1 shows the water quality of sewage in rainy weather before treatment, and Table 2 shows the test results. The contact time between sewage and dichloroglyoxime during rain was 1 minute.

Examples 7 to 10 In the same manner as in Example 1, a disinfection test for coliform bacteria according to the present invention was conducted using the sewage in rainy weather that overflowed from the rainwater discharge port as the water to be treated when the rainfall was 7 mm / hour. It was Table 1 shows the water quality of sewage in rainy weather before treatment, and Table 2 shows the test results. The contact time between sewage and dichloroglyoxime during rain was 1 minute.

Examples 11 to 14 A disinfection test for coliform bacteria according to the present invention was carried out in the same manner as in Example 1 using the sewage in rainy weather that overflowed from the rainwater spout at the time of rainfall of 7 mm / hour as treated water. It was Table 1 shows the water quality of sewage in rainy weather before treatment, and Table 2 shows the test results. The contact time between sewage and dichloroglyoxime during rain was 1 minute.

[0029]

[Table 1]

[0030]

[Table 2]

Examples 15 to 22 A disinfection test for coliform bacteria according to the present invention is carried out in the same manner as in Example 1 using the rainwater sewage overflowed from the sewage treatment plant as the water to be treated when the rainfall is 4 mm / hr. It was The disinfectant solution pumps up a part of the sewage in the case of rain, to which various concentrations of dichloroglyoxime as a disinfectant compound and 2,2-dibromo-3-dichloro-3-oxime at various ratios are used.
It was prepared by dissolving nitrilopropionamide. Table 1 shows the quality of sewage in rainy weather before treatment, and Table 3 shows the test results. The contact time between the sewage in rainy weather and the mixed antiseptic solution was 40 seconds.

[0032]

[Table 3]

Comparative Examples 1 to 5 A disinfection test for coliform bacteria was carried out using the rainwater sewage removed from the pumping station as the water to be treated at the same rainfall as that treated in Examples 1 to 6 when the rainfall was 5 mm / hour. It was The disinfectant solution
Sodium hypochlorite was added to sewage in rainy weather so as to have various concentrations. Table 1 shows the quality of sewage in rainy weather before treatment.
The test results are shown in Table 4. The contact time between sewage in rainy weather and sodium hypochlorite was 3 minutes.

[0034]

[Table 4]

As is clear from the results shown in the table above,
When using sodium hypochlorite as a disinfectant,
The result was that the number of coliforms could not be reduced to 3000 CFU / mL or less in a short time. Moreover, it was predicted that a large amount of residual chlorine would be detected, which would adversely affect aquatic organisms in the public water area to which it was released. In contrast, when the halogenated glyoxime was used as a disinfectant according to the present invention, the disinfection time was short and an effective disinfecting effect of coliform bacteria was recognized even with a small amount. Furthermore, when a disinfectant containing a brominated compound added to a halogenated glyoxime is used in a more preferred embodiment of the present invention, an effective disinfecting effect of coliform bacteria can be obtained in a shorter time.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the device according to the present invention.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) A01N 43/50 A01N 43/50 R 43/64 105 43/64 105 59/08 59/08 A C02F 1 / 50 510 C02F 1/50 510A 520 520P 531 531P 532 532C 532D 532H 550 550C 550D 550L ZAB ZAB

Claims (7)

[Claims] 1. A disinfectant for drainage, comprising a halogenated glyoxime. 2. The disinfectant for drainage according to claim 1, further comprising a bromine compound. 3. The brominated compound is 2,2-dibromo-3.
-Nitrilopropionamide, 1,2-bis (bromoacetoxy) ethane, 1,4-bis (bromoacetoxy)
Butene, 1-bromo-3-chloro-5,5-dimethylhydantoin, 1,3-dibromo-5,5-dimethylhydantoin, trichloroisocyanuric acid, dichloroisocyanuric acid, tribromoisocyanuric acid, dibromochloroisocyanuric acid, bromodichloro The disinfectant for drainage according to claim 2, comprising at least one or more of isocyanuric acid, dibromoisocyanuric acid, bromochloroisocyanuric acid, and hypobromite. 4. A device for disinfecting wastewater, comprising a device for supplying halogenated glyoxime to the wastewater. 5. The device according to claim 4, further comprising a device for supplying a bromine-based compound to the wastewater. 6. An apparatus for disinfecting wastewater, which is an apparatus for preparing a disinfectant solution by mixing a halogenated glyoxime and a bromine compound; and supplying the prepared disinfectant solution to the wastewater. A device for disinfecting waste water, which is provided with: 7. The device according to claim 4, further comprising a device for measuring turbidity and / or SS of waste water.