JPS63166492A - Method and apparatus for treating waste water - Google Patents

Abstract

PURPOSE:To provide high purifying capacity, by adding chlorine dioxide to waste water from which a solid, an oil component or the like are removed and further allowing said waste water to pass through a ceramics filter tank. CONSTITUTION:In the first filter part 1, waste water is transferred to the first tank 11 of a raw water pit 10 and filtered by an automatic screen 13 to remove impurity. Subsequently, the waste water is transferred to the second filter part 2 and a polymer flocculant is added to the first tank 20 of a reaction tank under stirring to perform the reactive flocculation of impurities such as a solid, an oil component or the like. Next, the waste water is transferred to the second tank 21 where a flocculation promoter such as aluminum sulfate is added under stirring to further flocculate impurities. This waste water is transferred to a pressure flotation apparatus 26 to remove impurities. Subsequently, the waste water is sent to the third filter part 3 and a pH control agent such as quartz is added to the waste water to neutralize the same and a special flocculant is added to the waste water under stirring to flocculate fine impurities. The formed floc is sedimented and separated in a flocculating sedimentation tank 36.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a wastewater treatment method and apparatus.

In particular, the present invention relates to a method and an apparatus suitable for treating wastewater from strata, wastewater from food factories, domestic wastewater, etc. containing putrefactive organic matter such as animal origin.

(Prior Art) Conventionally, wastewater containing organic matter has been mainly treated using an activated sludge method. The activated sludge method grows microorganisms such as bacteria, which adsorbs organic matter in the sludge.
It separates impurities by sedimentation and has high purification ability. Water treated by the activated sludge method was discharged directly into rivers, etc., in a state that satisfied certain water quality standards.

(Problem to be solved by the invention) However, when wastewater containing putrefactive organic matter such as animal matter is treated by this activated sludge method, the quality of the treated water obtained by this method satisfies the standard value for discharge. However, the pH is acidic, and the BOD and COD are both 30-60p.
The quality of the water was not necessarily sufficient in the sense that it was harmless to natural water bodies, such as the fact that it did not completely remove odor. In addition, the above-mentioned treated water was not suitable for reuse as factory water or washing water, and the equipment for the activated sludge method was complex and large-scale.
Equipment costs were high, and processing time was quite long.

Therefore, the present invention uses microorganisms such as bacteria to separate impurities in wastewater, which is different from the conventional activated sludge method, and uses simple and small-scale equipment to separate wastewater, especially wastewater. By deodorizing, sterilizing, and purifying wastewater that contains putrefactive organic matter such as animal products, recycled water with a quality equal to or better than tap water can be obtained, and there is not only no risk of contamination when it is discharged into natural water bodies, but it can also be used over a wide range of areas. An object of the present invention is to provide a wastewater treatment method and apparatus that can obtain reclaimed water suitable for reuse.

(Means for solving the problem) In order to achieve the above object, the present invention adds chlorine dioxide to wastewater from which solids, oil, etc. have been removed through appropriate filtration, reaction or precipitation tanks, and then filters the wastewater through ceramic filtration. The present invention provides a wastewater treatment method characterized by passing the wastewater through a tank, and a wastewater treatment apparatus including a configuration in which a ceramic filtration tank is provided and a chlorine dioxide adding device is disposed on the inflow side of the wastewater.

Preferably, the ceramic filtration tank is divided into a plurality of chambers, and the wastewater is configured to pass through each of the divided filtration tanks from bottom to top.

(Example) Next, the wastewater treatment method and its apparatus of the present invention will be explained based on the drawings. The raw water to be purified here is wastewater containing putrefactive organic matter, but it may be other wastewater.

In this embodiment, the entire wastewater treatment apparatus is configured so that the wastewater is introduced into the main apparatus of the present invention after undergoing a pretreatment process to remove as much solid content, oil, etc. from the wastewater as possible. The first to fourth filtration sections 1 to 4 shown in FIG. 1 show this pretreatment process, and conventional filtration means can be combined as appropriate, but in this example, the following Illustrate the means.

First, the main purpose of the first filtration section 1 is to remove large-particle impurities such as solids from wastewater, and an automatic screen 13 is provided to filter the wastewater and remove large-particle solids. A raw water pit 10 is provided in which a first tank 11 and a second tank 12 are arranged, and wastewater is first introduced into the first tank 11 and then passed through an automatic screen 13 to be transferred to the second tank 12. A tank 14 that stores solids removed by the automatic screen 13, a raw water tank 15 that stores wastewater flowing out from the second tank 12, and the raw water tank 1.
The measuring tank 16 transfers the water to the next second filtration part 2 while adjusting the flow rate and flow rate that can process the water of No. 5 per unit time.

The main purpose of the second filtration section 2 is to remove minute impurities such as oil that could not be removed in the first filtration section 1. A reaction tank 22 is formed which includes a first tank 20 and a second tank 21 for re-coagulating the wastewater transferred from the first tank 20, and each type 20, 21 is provided with an agitator 25. ing. In addition, coagulant injection devices 23 and 24 are provided for adding a polymer coagulant to the first tank 20 and a special coagulant to the second tank 21, respectively, and furthermore, waste water that has undergone a coagulation reaction in the second tank 21 is provided. A pressurized flotation device 26 is provided to separate and remove coagulated impurities from this wastewater. The pressurized flotation device 26 is configured to introduce waste water and inject pressurized air using a pressurized air injector 28 having a compressor to separate impurities in the waste water and remove the impurities using a skimmer 27.

The second filtration section 3 has the main purpose of removing further minute impurities that were not removed by the second filtration section 2, and receives the wastewater introduced through the pressure flotation device 26, and controls the pH value of the wastewater. A reaction tank 22 is formed, which includes a first tank 30 for adjusting the wastewater and a second tank 31 for further solidifying the wastewater transferred from the first tank 30.
31 is provided with a stirrer 35, respectively. Also,
The first tank 30 is provided with an injection device 33 for adding a PH value adjusting agent, and the second tank 31 is provided with a forging agent injection device 34 for adding a special coagulant. A coagulation-sedimentation tank 36 is formed into which the wastewater subjected to the coagulation reaction in the tank 31 is introduced, and coagulation impurities are separated and removed from the wastewater. The coagulation sedimentation tank 36 is equipped with a skimmer 37 that filters impurities.
It is equipped with The water from which impurities have been removed in the coagulation and sedimentation tank 36 is temporarily sent and stored in a supernatant water tank 38.

The fourth filtration section 4 has the main purpose of removing sand from the supernatant water tank 38, and a ceramic filtration tank 5 to be described later.
It is formed by a sand filter 40 disposed in the middle of water supply to 0.

The main purpose of the bag y15 of the present invention is to deodorize, sterilize, and finally purify the wastewater from which impurities have been removed as described above, and as shown in FIG. has been done.

The ceramic filtration tank 50 is formed by dividing into a plurality of chambers,
An inlet 52 is provided in the first section, and a porous soft ceramic 51 made of ceramic, preferably microbubbles with a firing temperature of 900 degrees or less, is disposed in each section, and water flows through the ceramic. Water flows naturally through the inlet 52 and naturally passes through each section from bottom to top. The chlorine dioxide injection device 53 is formed to be able to add chlorine dioxide to the inlet 52 side. Further, a water storage tank 54 is formed which stores the water collected in the ceramic filtration tank 50 and is provided with a spout 56 . The tank 54 is equipped with a pump 55 set in a flow path for transferring and recirculating the stored water to the fourth filtration section 4 or the ceramic filtration tank 50 again.

Note that the filtration process up to the transfer to the device 5 of the present invention is performed in the first filtration section! as described above. In addition to the four stages of the fourth filtration section 4, it is possible to increase or decrease the number of stages or change the filtration device depending on the quantity and quality of impurities contained in the waste water.

When treating wastewater containing putrefying organic matter with the five-stage device from the above-mentioned filtration section 1 to the device 5 of the present invention, first, the wastewater is transferred to the first tank of the raw water bit 10 in the filtration section 1. ! Transfer to l. The wastewater is filtered through an automatic screen 13 to remove large-particle solids, such as body hair and organ residues contained in aquifer wastewater, and food and other impurities contained in food improvement wastewater and domestic wastewater. Impurities accumulate in the tank 14, and the filtered water is transferred to the second tank 12 and stored in the raw water tank 15 by a pump or the like. Here, it is preferable to add a small amount of chlorine dioxide to the wastewater in the raw water tank 15 in order to stop the growth of bacteria such as bacteria. , and is transferred to the next second filtration section 2 while adjusting the flow rate in the measuring tank 12.

A polymer coagulant is added by a coagulant injection device 23 to the first tank 20 of the reaction tank of the second filtration part 2 to which the wastewater from the first filtration part 1 has been transferred, and is stirred by the stirrer 25 to remove minute impurities. Impurities such as certain oils react and coagulate. Next, a coagulation accelerator such as sulfuric acid is added to the second tank 21 into which the wastewater from the first tank 20 has been transferred using the coagulant injection device 24, and the agitator 2
By stirring at step 5, the reaction is promoted and impurities are solidified. The wastewater in this second tank 21 is transferred to the pressurized flotation device 2.
6.

Air pressurized by a compressor is sent from an injection device 28 to the pressurized flotation device 26, so that minute impurities solidified in the reaction tank 22 are filtered by a skimmer 27.
Impurities are stored in the sludge tank 29 as appropriate. The wastewater from which impurities have been removed in this way is transferred to the next third filtration section 3.

A p)Tfl regulator such as lime is added to the first tank 30 of the reaction tank of the third filtration unit 3 using the P① clay regulator injection device 33, and is stirred by the stirrer 35 to prevent acidification due to putrefying organic matter. The wastewater becomes almost neutral. A special coagulant is added to the second tank 31 into which the pH-adjusted wastewater has been transferred using the coagulant injection device 34 and stirred by the stirrer 35, so that the minute impurities that have not been removed so far react and coagulate. do. The wastewater in this second tank 31 is transferred to a coagulation sedimentation tank 36.
will be transferred to.

In the coagulation-sedimentation tank 36, impurities coagulated by a special coagulant are separated by sedimentation, filtered by a skimmer 37, and stored in a sludge tank 29 as appropriate.The wastewater from which impurities have been removed in this way is transferred to a supernatant water tank 38, and then used for the next process. It is transferred to the fourth filtration section 4.

In the fourth filtration section 4, the water in the supernatant water tank 38 is transferred to the sand filter 40.
is filtered and transferred to the next apparatus 5 of the present invention.

The water filtered by the fourth filtration section 4 is allowed to naturally flow into the ceramic filtration tank 50 of the device 5 of the present invention from the inlet 52, and at the same time, chlorine dioxide is added by the injection device 53. Chlorine dioxide has the characteristic of being particularly reactive to putrid substances, and its use can provide deodorizing and sterilizing effects. The amount of chlorine dioxide added should be approximately 40 to 80 ppm relative to the amount of treated wastewater when eliminating strong odors from aquifer wastewater and reusing it for uses other than drinking water such as washing water. If it is weak, it should be 40ppm or less.
Further, when the recycled water is used for drinking, it is preferable that the amount is 20 ppffl or less.

By mixing chlorine dioxide into the water in this way, the water is deodorized and sterilized, and the water naturally passes from bottom to top through the fine bubbles of the soft ceramic 51 formed in the filtration tank 50, which is divided into a plurality of sections, and ions are removed. This exchange mineralizes the water, ensures further deodorization and sterilization, and at the same time removes chlorine. Here, by making the bubbles of the soft ceramic 51 more fine, the effects of deodorization, purification by sterilization, and mineralization can be enhanced. From the ceramic filtration tank 50, purified and mineralized reclaimed water is obtained as described above.

The recycled water is temporarily stored in the water storage tank 54, and can be taken out from the water outlet 56 of the tank 54 and reused as recycled water if necessary. In order to prevent the water quality from deteriorating due to the recycled water being stored in the tank 54 for a long time, the pump 55 transfers the recycled water from the tank 54 to the fourth filtration layer 4 or the ceramic filtration tank 50 and circulates it. It is preferable to do this, so that recycled water of good quality is always stored.

The quality of the reclaimed water obtained by the present invention as described above was determined by water quality testing of reclaimed water randomly extracted during one day of continuous treatment while adding 40 ppm of chlorine dioxide to aquifer wastewater. According to the results of a request to the Pollution Control Association, the pH value is 7.6 and the chlorine ion concentration is Q.
BOD (biological oxygen demand) is 3.6 ppm, CO
D (chemical oxygen demand): 3.2 ppm, coliform bacteria: 0, suspended solids: 5.0 ppm or less (no detected values were obtained in this test), hexane extractable substances: 2.5 ppm or less (same) Judging from the above results obtained by adding chlorine dioxide at a rate of 40 ppm, it was found that the quality of recycled water was equivalent to or better than that of tap water. Twenty people tasted the recycled water, and all found that it tasted lighter and sweeter than tap water, similar to so-called natural mineral water.

According to the test results of the above-mentioned Pollution Control Association, the quality of the aquifer wastewater before treatment has a pH value of 5.8, a BOD (biological oxygen demand) of 845 ppm, and a COD (chemical oxygen demand). ) is 236 ppm, suspended solids are 730 ppm,
The amount of hexane extracted substance was 13 appm, which shows that the present invention has an extremely high purification ability.

When the recycled water produced by the above device is used as factory water or water for various purposes other than washing water, if the used water is purified again with the above device, it can be used as recycled water any number of times, saving water resources. useful for.

In addition, the device 5 of the present invention is characterized by being equipped with a simple aim of a ceramic filtration tank 50 and a chlorine dioxide injection device 53 in order to deodorize, sterilize, and purify wastewater. Even including the equipment, the equipment is simpler and smaller than the conventional activated sludge method that uses bacteria, etc. Therefore, equipment costs are low and processing time is also shortened. .

Note that since the impurities removed by the pressure flotation device 26 and the coagulation sedimentation tank 36 are organic substances, they can be used as fertilizer or compost by applying appropriate treatment.

(Effects of the Invention) As described above, the present invention adds chlorine dioxide to wastewater from which solids, oil, etc. have been removed through appropriate filtration, reaction or precipitation tanks, and also allows the wastewater to pass through a ceramic filtration tank. Because of its characteristics, it is possible to deodorize, sterilize, and purify wastewater, especially wastewater containing putrefactive organic matter such as animal origin, and mineralize it at the same time, thereby obtaining recycled water with a quality equal to or higher than that of tap water. Therefore, this reclaimed water is not only suitable for wide-area reuse, but also poses no risk of contamination when released into natural water bodies.

Moreover, when the recycled water obtained by the present invention is used, if the water after use is purified again by the present invention, it can be used as recycled water any number of times, which is useful for saving water resources.

The present invention is characterized by being equipped with a simple mechanism of a ceramic filtration tank and a chlorine dioxide addition device in order to deodorize, sterilize, and purify wastewater. Compared to the law, the equipment is Mj
＆And it is small-scale, so the equipment cost is low and the processing time is also shortened.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing the pretreatment process of the present invention, and FIG. 2 is a system diagram showing the main processing process of the present invention. ■--first filtration section, 2-second filtration section, 3-third filtration tank,
4-Fourth filtration section, 5-.1 device of the present invention, 50.--ceramic filtration tank, 5.--soft ceramics, 52.
- Inflow port, 53... Chlorine dioxide injection device, 54- Water storage tank, 55...- Pump, 56... Water outlet. Applicant Fuji 1) Engraving of Sanai drawing (no change in content) 27 Fu (Ete-55 O (Schiff 1) 28 Emphasis on 9 Hiro entry 56゜LLa32 L Civil tank procedure amendment book February 1986 5th 2. Title of the invention: Wastewater treatment method and device 3. Amended person: Fujita Sanai 4. Agent: Yu 101. 5. Spontaneous amendment.

Claims (3)

[Claims] (1) Add chlorine dioxide to wastewater from which solids, oil, etc. have been removed through appropriate filtration, reaction or settling tanks, and
A wastewater treatment method characterized by passing the wastewater through a ceramic filtration tank. (2) A wastewater treatment device including a configuration in which a ceramic filtration tank is provided and a chlorine dioxide addition device is provided on the inflow side of the wastewater. (3) The wastewater treatment device according to item 2, wherein the ceramic filtration tank is divided into a plurality of chambers, and the wastewater is configured to pass through each divided filtration tank from bottom to top.