JPH11128960A - Deodorization of stink water, etc., and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deodorization method and an apparatus therefor wherein water to be treated contg. stink substances or malodorous substances is brought into contact with air or oxygen contg. ozone by using a small-sized apparatus and an ordinary pump as a pump for feeding the water to be treated and the reaction time can be extended and deodorization can be efficiently performed. SOLUTION: An ejector 25 is provided with an inlet part 26 for making water to be treated flow in, a suction opening part 27 for air or oxygen contg. ozone to be mixed with the water to be treated flowing in from this inlet part 26 and an outlet part 28 for making the water treated by gas-liq. mixing with the air of oxygen contg. ozone sucked from the inlet part 27 flow out. In the ejector 25, the inlet part 26 ad the outlet part 28 are arranged at a horizontal position. A spiral reaction pipe 30 connected with the outlet part 28 of the ejector 25 is arranged at a lower position than the outlet part 28. In the spiral reaction pipe 30, the water to be treated gas-liq. mixed with the air or oxygen contg. ozone is deodorized by performing ozone oxidative reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for deodorizing odorous substances contained in clean water or odorous wastewater, which are said to be musty, and offensive odorous substances which are deodorized by ozone oxidation of odorous substances.

[0002]

2. Description of the Related Art Various studies have been made on a method of deodorizing an odorous substance or a malodorous substance contained in water such as clean water or waste water by oxidizing it with ozone. I have. However, deodorization due to malodorous substances in wastewater is in the stage of finally entering the practical stage from the research stage because the ozone generation equipment is expensive.

[0003] A conventionally used apparatus for injecting ozone into a liquid phase is generally a method in which a diffuser is installed in a lower part of an ozone contact tank to inject ozone and contact the water to be treated in the ozone contact tank, or a packed tower. Gas-liquid contact, or, for example, the "Water Wastewater Handbook (2)"
As described on page 306 of the Industrial Water Research Council (issued in December 1973), a method is known in which ozone and gas-liquid mixed water to be treated are flowed into an ozone contact tank by an ejector to cause a contact reaction. ing.

[0004] As shown in FIG. 2, an ejector 2 is provided above an ozone contact tank 1, as shown in FIG. 2. The ejector 2 has an ozone suction port 4 formed at an intermediate portion for suctioning by the water to be treated flowing from the upper inlet part 3, and an outlet 5 for a gas-liquid mixture of ozone and the water to be treated. An opening is formed near the bottom of the contact tank 1, and an overflow port 6 formed on the upper part of the contact tank 1 is communicated with a gas-liquid separation tank 7, and a treated water drain port 8 is provided at a lower part of the gas-liquid separation tank 7. A structure is provided in which an exhaust port 9 is provided at the top while being provided.

In the apparatus shown in FIG. 2, the solubility of ozone in the water to be treated is superior to that of a device using a diffuser, and the amount of self-decomposition of ozone is small. Although the reactivity of ozone is high, the use efficiency of ozone is improved. On the other hand, in order to dissolve ozone well in the water to be treated and to maintain the contact time to some extent due to the necessity of promoting the oxidation reaction, the ozone suction port 4 of the ejector 2 It is necessary to increase the length from the outlet 5 to the outlet 5, and it is necessary to increase the amount of water to be treated used for sucking ozone.

However, there is a practical limit to increasing the length from the ozone suction port 4 to the outlet 5 of the ejector 2, and the water to be treated extends from the ozone suction port 4 to the outlet 5 of the ejector 2. The flowing time is about several seconds at the longest, and it is necessary to keep the water to be treated in the contact tank 1 for several minutes or more. Since the supply amount of the water to be treated is large, a complete mixing type is required to maintain the contact time. The contact tank 1 had to be used, and the contact tank had to be large and deep. This means that the supply of the water to be treated to the ejector 2 necessarily requires the use of a pump having a high discharge pressure and a large discharge amount, resulting in an increase in equipment costs of the entire apparatus.

As shown in FIG. 3, a gas-liquid mixing chamber 12 having an inlet 10 for water to be treated and an ozone supply port 11 is provided. Water outlet
13 is inserted through the middle part of one side wall of the contact tank 14 and is located near the middle part of the other side wall, and is opened in the contact tank 14.
Inside 14, partition walls 15 are formed horizontally from both side walls alternately,
A meandering flow path 17 is formed in the flow gap 16 between the tip of each partition wall 15 and the wall surface of the contact tank 14.
A treated water drainage port 18 is provided at the bottom of the
There has been proposed an apparatus which is provided with 19 and prolongs the contact time between the water to be treated and ozone.

However, the apparatus shown in FIG.
In order to extend the contact time, the length of the contact tank 14 must be increased, and the entire apparatus becomes large.
Since the gas phase rises against the water flow, the upper part of the contact tank 14 becomes a gas phase.Even if the contact tank 14 is enlarged, the effect of extending the contact time between the water to be treated and ozone is small, and the oxidation reaction efficiency is reduced. Has low problems.

[0009]

The conventional deodorizing apparatus shown in FIG. 2 has excellent ozone solubility.
The reactivity with off-flavor substances and malodorous substances has a high advantage, but the discharge pressure and volume of the water to be treated required for sucking ozone into the ejector are large, and the contact between ozone and the treated water is high. In order to lengthen the time, it is necessary to increase the length from the ozone suction port 4 to the outlet 5 of the ejector 2, and the contact tank 1 having a deep water is inevitably required. In the apparatus, not only is the contact tank 14 elongated in the horizontal direction, but also the proportion of the gas phase is higher than the size, and the contact time between ozone and the water to be treated is longer than the size of the contact tank 14. However, the size of the contact tank was limited in any of the apparatuses, and there was a problem in practical use.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is a small-sized device. The pump for supplying the water to be treated is a general pump that removes air or oxygen containing ozone and an off-odor substance or an off-odor substance. An object of the present invention is to provide a method for deodorizing off-odor water and the like, which can increase the contact reaction time with the water to be treated, and can efficiently deodorize water, and a device therefor.

[0011]

According to a first aspect of the present invention, there is provided a method for deodorizing off-flavor water or the like, wherein water to be treated flows from an inlet of an ejector in which an inlet and an outlet are disposed horizontally.
The water to be treated flowing from the inlet of the ejector and the air or oxygen containing ozone sucked from the suction port formed in the middle of the ejector are mixed in a gas-liquid state, and the air or oxygen containing the ozone is mixed in a gas-liquid mixture. The treated water flows through a spiral reaction tube disposed at a position lower than the ejector position in a gas-liquid mixed state, and is deodorized by an oxidation reaction.

[0012] Then, water to be treated containing off-flavor substances such as off-flavor water and malodorous substances is caused to flow in from the inlet of the ejector, and formed in the middle of the ejector by the water to be treated flowing from the inlet of the ejector. Air or oxygen containing ozone is sucked from the suction port and mixed with the water to be treated in a gas-liquid manner. The water to be treated, which has been gas-liquid mixed by the ejector, flows from the outlet of the ejector into a spiral reaction tube provided at a position lower than the ejector, and the water to be treated is vaporized while passing through the spiral reaction tube. In the liquid mixture state, ozone is dissolved in the water to be treated and reacts with an off-flavor substance or an off-flavor substance to perform deodorization.

Since the spiral reaction tube is disposed at a position lower than the ejector, the water to be treated flowing into the spiral reaction tube from the outlet of the ejector flows smoothly without resistance, and the size of the spiral reaction tube is large. As compared with the above, the flow distance is longer, the oxidation reaction time of the water to be treated with ozone is longer, and the water to be treated is deodorized.

The method for deodorizing off-flavor water according to the invention of claim 2 is the same as the method for deodorizing off-flavor water etc.
The water to be treated is clean water containing one or two of 2-methylisoborneol and diosmin.

[0015] Then, 2-methylisoborneol and / or diosmin contained in the water to be treated is deodorized by an oxidation reaction with ozone.

According to the third aspect of the present invention, there is provided a method for deodorizing off-flavor water or the like according to the first aspect.
The water to be treated is wastewater containing one or more of methyl mercaptan, hydrogen sulfide, methyl sulfide, and methyl disulfide.

The methyl mercaptan, hydrogen sulfide, methyl sulfide, and methyl disulfide contained in the water to be treated are deodorized by an oxidation reaction with ozone.

According to a fourth aspect of the present invention, there is provided an apparatus for deodorizing off-flavor water or the like, wherein an inlet for inflowing the water to be treated, a suction port for air or oxygen containing ozone mixed with the water to be treated flowing from the inlet, and An ejector having an outlet through which air to be treated mixed with air or oxygen containing ozone sucked in from the inlet and gas-liquid mixed, and having the inlet and the outlet arranged in a horizontal position; A spiral reaction tube connected to the outlet of the ejector and disposed at a position lower than the outlet of the ejector and configured to oxidize and deodorize water to be treated mixed with air or oxygen containing ozone or oxygen and deodorize the water. .

Then, the water to be treated containing off-flavor substances such as off-flavor water and malodorous substances is caused to flow in from the inlet of the ejector, and is formed in the middle of the ejector by the water to be treated flowing from the inlet of the ejector. Air or oxygen containing ozone is sucked from the suction port and mixed with the water to be treated in a gas-liquid manner. The water to be treated, which has been gas-liquid mixed by the ejector, flows from the outlet of the ejector into a spiral reaction tube provided at a position lower than the ejector, and the water to be treated is vaporized while passing through the spiral reaction tube. In the liquid mixture state, ozone is dissolved in the water to be treated and reacts with an off-flavor substance or an off-flavor substance to perform deodorization.

Since the spiral reaction tube is disposed at a position lower than the ejector, the water to be treated flowing into the spiral reaction tube from the outlet of the ejector flows smoothly without resistance, and the size of the spiral reaction tube is large. As compared with the above, the flow distance is longer, the oxidation reaction time of the water to be treated with ozone is longer, and the water to be treated is deodorized.

According to a fifth aspect of the present invention, there is provided the deodorizing apparatus for off-flavor water or the like according to the fourth aspect.
The water to be treated is clean water containing one or two of 2-methylisoborneol and diosmin.

Then, 2-methylisoborneol and / or diosmin contained in the clean water of the water to be treated is deodorized by an oxidation reaction with ozone.

In the deodorizing apparatus for off-flavor water according to the present invention, the water to be treated is waste water containing one or more of methyl mercaptan, hydrogen sulfide, methyl sulfide and methyl disulfide.

Then, methyl mercaptan, hydrogen sulfide, methyl sulfide, and methyl disulfide contained in the water to be treated are deodorized by an oxidation reaction with ozone.

[0025]

FIG. 1 shows an embodiment of the present invention.
It will be described based on FIG.

In FIG. 1, the water to be treated which has flowed into the water tank to be treated 20 from an inflow pipe 21 is sucked by a pump 23 from a suction pipe 22, and is discharged from an inlet port of an ejector 25 through a discharge pipe 24 connected to the pump 23. Flowed into 26.

The ejector 25 has an inlet 26 into which the water to be treated flows, a suction port 27 for air or oxygen containing ozone mixed with the water to be treated flowing from the inlet 26, and a suction from the suction port 27. And an outlet 28 for discharging the water to be treated mixed with air or oxygen containing gas or ozone containing the ozone.The ejector 25 has an inlet 26 and an outlet 28 which are disposed horizontally in a horizontal position. It is arranged.

An ozone generator 29 is connected to a suction port 27 for air or oxygen containing ozone in the ejector 25.

The outlet 28 of the ejector 25 is disposed at a position lower than the outlet 28 of the ejector 25 to deoxidize the water to be treated mixed with air containing ozone or oxygen and gas and liquid by oxidation reaction. The upper end of the spiral reaction tube 30 is connected to the upper end. This spiral reaction tube
Numeral 30 is formed of a spirally wound tube such that one end is on the upper side and the other end is on the lower side. The spiral reaction tube 30 is wound around a cylinder (not shown) in a spiral shape and retained.

A gas-liquid separation tank 32 is connected to a lower end of the spiral reaction tube 30 through a communication tube 31. A treated water discharge port 33 is formed at an intermediate portion of the gas-liquid separation tank 32, and an exhaust pipe 35 provided with a catalyst layer 34 is provided above the gas-liquid separation tank 32.

Next, the operation of this embodiment will be described.

The water to be treated which has flowed into the treated water tank 20 from the inflow pipe 21 flows in from the inlet 26 of the ejector 25 in which the inlet 26 and the outlet 28 are disposed in a horizontal position by the drive of the pump 23.
The water to be treated flowing from the inlet 26 of the ejector 25 is mixed with air or oxygen containing ozone generated by an ozone generator 29 sucked from a suction port 27 formed at an intermediate portion of the ejector 25 in a gas-liquid mixture. The water to be treated, which is gas-liquid mixed with air or oxygen containing ozone, flows in a spiral reaction tube 30 disposed at a position lower than the position of the ejector 25 in a gas-liquid mixed state, and the spiral reaction tube 30 While flowing, ozone is dissolved in the water to be treated, and the water to be treated is deodorized by an oxidation reaction between the off-odor substance or the malodorous substance and the ozone.

Since the spiral reaction tube 30 is disposed at a position lower than the ejector 25, the water to be treated flowing into the spiral reaction tube 30 from the outlet 28 of the ejector 25 becomes a piston flow, Even if the discharge pressure is not high, the spiral reaction tube 30 flows smoothly without resistance, the flow length of the spiral reaction tube 30 is longer than the size, and the oxidation reaction time of the water to be treated with ozone is longer. Since the water to be treated is deodorized, the ozone oxidation reaction time can be shortened as compared with the conventional apparatus shown in FIGS.

The treated water deodorized while flowing through the spiral reaction tube 30 flows into the gas-liquid separation tank 32 and is separated from air or oxygen, and the treated water flows out from the treated water discharge port 33. It flows to the next processing step as needed.

The air or oxygen separated from the treated water in a gas-liquid mixed state flowing out of the spiral reaction tube 30 and flowing into the gas-liquid separation tank 32 is separated from the exhaust pipe 35 of the gas-liquid separation tank 32 into the atmosphere. Released. When unreacted ozone is contained in the exhausted air or oxygen, the unreacted ozone is removed from the catalyst layer.
Decomposed at 34 and released into the atmosphere.

In the above embodiment, the ejector 25
The spiral reaction tube 30 connected to the outlet portion 28 of the spiral reaction tube 30 becomes compact because of the spiral shape even if it is lengthened to obtain a long reaction time, and is covered by increasing the number of turns of the reaction tube of the spiral reaction tube 30. The contact time between the treated water and ozone can be extended, and the reaction apparatus can be downsized even when the reaction rate between the off-odor substance and the malodorous substance and ozone is low.

By appropriately adjusting the amount of ozone according to the concentration of off-flavor substances in the water to be treated, the residence time in the spiral reaction tube 30 is about 5 seconds, preferably about 10 seconds, and almost deodorization can be achieved. It could be confirmed.

The water to be treated flowing through the spiral reaction tube 30 undergoes an ozone oxidation reaction in a piston flow state, so that the reaction volume can be reduced. In addition, since the reaction proceeds sequentially in the spiral reaction tube 30, Even if the use efficiency of ozone is high and the number of turns of the spiral reaction tube 30 is increased, it is not necessary to greatly increase the installed volume of the reaction device.

[0039]

【Example】

Example 1 A reaction tube connected to an outlet 28 of an ejector 25 shown in FIG. 1 has an inner diameter of 30 mm and a length of 5,000 mm, and is wound around a cylindrical tube having an outer diameter of 700 mm approximately 23 times into a spiral reaction tube.
Using a device in which a 10-liter gas-liquid separation tank 32 is connected to the spiral reaction tube 30, water to be treated having a concentration of 30 mg / l of 2-methylisoborneol (2-MIB) is ozone-oxidized. did. The entire spiral reaction tube 30 has a cylindrical shape with a diameter of about 800 mm and a height of about 800 mm.

Then, the above-mentioned water to be treated is supplied to the ejector 25 at a rate of 20 l / min, and air generated at an ozone generation amount of 80 mg / min from the ozone generator 29 is mixed with the ejector 25 by suction and mixed with 2-methylisoborneol. And reacted.

As a result, the concentration of 2-methylisoborneol in the water to be treated at the outlet of the spiral reaction tube 30 was 4.
At 5 mg / l, the odor of 2-methylisoborneol was not felt in the treated water from which unreacted ozone was removed.

Comparative Example 1 Ejector 2 shown in FIG.
Length from ozone inlet 4 to outlet 5 is 1,500 mm
The water to be treated containing 2-methylisoborneol was subjected to ozone oxidation treatment in a 300-liter ozone contact tank 1 under the same conditions as in Example 1.

As a result, the concentration of 2-methylisoborneol in the water to be treated at the overflow port 6 of the ozone contact tank 1 was 8.3 mg.
/ L, and the treated water from which unreacted ozone was removed showed an off-flavor of 2-methylisoborneol.

Example 2 Ejector 25 shown in FIG.
The reaction tube connected to the outlet 28 has an inner diameter of 15 mm and a length of 3,000
0 mm and wound about 20 times around a cylindrical tube with an outer diameter of 500 mm to form a spiral reaction tube 30.
Using a device connected to a 10-liter gas-liquid separation tank 32, the water to be treated having a concentration of dimethyl sulfide of 0.1 mg / l was subjected to ozone oxidation. The entire spiral reaction tube 30 has a diameter of about
It has a cylindrical shape with a height of 600 mm and a height of about 450 mm.

Then, the water to be treated is supplied to the ejector 25 at a rate of 15 l / min, and air generated at an ozone generation amount of 20 mg / min from the ozone generator 29 is mixed with the ejector 25 by suction and mixed with 2-methylisoborneol. And reacted.

As a result, the concentration of dimethyl sulfide in the water to be treated at the outlet of the spiral reaction tube 30 was not detected (the lower limit of quantification was 0.005 mg / l, and dimethyl sulfide was contained in the treated water from which unreacted ozone was removed). No odor was felt.

Comparative Example 2 Ejector 2 shown in FIG.
Length from ozone inlet 4 to outlet 5 is 1,500 mm
The ozone oxidation treatment was carried out on the water to be treated containing dimethyl sulfide in the ozone contact tank 1 having a volume of 300 l under the same conditions as in Example 2.

As a result, the concentration of dimethyl sulfide in the water to be treated at the overflow port 6 of the ozone contact tank 1 was 0.024 mg / l,
The odor of dimethyl sulfide was felt in the treated water from which unreacted ozone was removed.

In the apparatus used in the comparative example, in order to prevent the concentration of dimethyl sulfide from being detected, the length from the ozone inlet 4 to the outlet 5 of the ejector 2 was set to 4,000 mm, and the ozone contact was made. It was confirmed that the volume of the tank 1 needed to be 800 l, and it was found that the apparatus became large and the equipment cost increased.

[0050]

According to the first aspect of the present invention, the water to be treated containing off-flavor substances such as off-flavor water and malodorous substances can be treated with ozone in a short residence time. While passing through the tube, ozone is dissolved in the water to be treated in a gas-liquid mixed state and reacts with off-flavor substances or malodorous substances to deodorize, increasing the efficiency of use of ozone. The incoming treated water flows in smoothly without resistance, the spiral reaction tube has a longer flow distance compared to its size, and the treated water has a longer oxidation reaction time with ozone, making it possible to reduce the size of the equipment, The moldy odor due to the off-flavor substance and the malodor of the malodorous substance in the wastewater can be surely obtained by the cheap device.

According to the second aspect of the present invention, 2-methylisoborneol and / or diosmin contained in the tap water is subjected to an ozone oxidation reaction of one or two kinds of ozone, and the off-odor of the tap water is deodorized.

According to the third aspect of the present invention, one or more of the malodorous substances of methyl mercaptan, hydrogen sulfide, methyl sulfide, and methyl disulfide contained in the waste water are oxidized with ozone to deodorize the odor. You.

According to the fourth aspect of the present invention, the water to be treated containing off-flavor substances such as off-flavor water and malodorous substances can be treated with ozone in a short residence time. During the passage, ozone is dissolved in the water to be treated in a gas-liquid mixed state and reacts with off-flavor substances or malodorous substances to perform deodorization, so that the use efficiency of ozone is increased and the ozone flows from the ejector into the spiral reaction tube. The water to be treated flows smoothly without resistance, the flow length of the spiral reaction tube is longer than the size, the time of the water to be treated is longer for the oxidation reaction with ozone, the apparatus can be made smaller, The moldy odor due to the substance and the odor of the odorous substance in the wastewater can be reliably achieved with an inexpensive device.

According to the second aspect of the present invention, one or two kinds of ozone of 2-methylisoborneol and / or diosmin contained in the tap water undergoes an ozone oxidation reaction, and the off-odor of the tap water is deodorized.

According to the third aspect of the present invention, one or more of the malodorous substances contained in the wastewater, such as methyl mercaptan, hydrogen sulfide, methyl sulfide, and methyl disulfide, are oxidized with ozone to deodorize the odor. You.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an apparatus for performing a method for deodorizing off-flavor water or the like according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an apparatus for implementing a conventional method for deodorizing off-flavor water or the like.

FIG. 3 is an explanatory view of another apparatus for performing a conventional method for deodorizing off-flavor water or the like.

[Explanation of symbols] 25 Ejector 26 Inlet 27 Inlet 28 Outlet 30 Spiral reaction tube

Claims (6)

[Claims] 1. Injection of water to be treated flows from an inlet of an ejector in which an inlet and an outlet are disposed in a horizontal position, and is formed at an intermediate portion between the water to be treated flowing from the inlet of the ejector and the ejector. The air or oxygen containing ozone inhaled from the mouth is gas-liquid mixed, and the water to be treated, which is gas-liquid mixed with the air or oxygen containing ozone, is disposed at a position lower than the ejector position in a gas-liquid mixed state. A deodorizing method for off-flavor water or the like, characterized by flowing a spiral reaction tube to deodorize by an oxidation reaction. 2. The method according to claim 1, wherein the water to be treated is clean water containing one or two kinds of 2-methylisoborneol and diosmin. 3. The method according to claim 1, wherein the water to be treated is wastewater containing one or more of methyl mercaptan, hydrogen sulfide, methyl sulfide, and methyl disulfide. 4. An inlet for inflowing the water to be treated, a suction port for air or oxygen containing ozone mixed with the water to be treated flowing in from the inlet, and air or ozone containing ozone inhaled from the suction port. An ejector having an outlet part for discharging the water to be treated mixed with oxygen and gas, the inlet part and the outlet part being arranged in a horizontal position; and an ejector connected to the outlet part of the ejector and being lower than the outlet part of the ejector. A deodorizing device for odorous water or the like, comprising: a spiral reaction tube disposed at a position for oxidizing and deodorizing water to be treated mixed with air or oxygen containing ozone or air and oxygen. 5. The deodorizing apparatus according to claim 4, wherein the water to be treated is clean water containing one or two kinds of 2-methylisoborneol and diosmin. 6. The deodorizing apparatus according to claim 4, wherein the water to be treated is wastewater containing one or more of methyl mercaptan, hydrogen sulfide, methyl sulfide, and methyl disulfide.