JPH01184097A - Treatment of waste water and equipment thereof - Google Patents

Abstract

PURPOSE:To subject waste water to purifying treatment biologically and efficiently and to miniaturize the installation by providing a raw water pump for feeding waste water in a raw water tank to a rotary biological contact mechanism and providing a discharge port for feeding water to be treated of this mechanism to an aeration tank. CONSTITUTION:After introducing waste water to be treated into a raw water tank, waste water in this raw water tank is fed to a rotary biological contact mechanism by a raw water pump and herein fixing microorganisms are preferentially bread and grown and waste water is biologically subjected to purifying treatment. Then the water to be treated of this rotary biological contact mechanism is allowed to fall to an aeration tank of the lower part through its discharge port and fed thereto and in this aeration tank, floating microorganisms are preferentially bred and the fed water to be treated is subjected to purifying treatment. The fixing microorganisms remaining in the deep layer part of the aeration tank 1 are transferred into a regulation section 9 from the bottom part of a partition wall 8 and returned to the rotary biological contact mechanisms 2 via a circulation pump 11 and a measuring tank 5 and the fixing microorganisms are rebred.

Description

Detailed Description of the Invention Object of the Invention The present invention relates to a wastewater treatment method and device, and provides a method and device that can purify various wastewaters rationally and efficiently using relatively compact equipment. This is what we are trying to do.

(Industrial application field) Technology for purifying domestic wastewater as well as wastewater from various companies.

(Conventional technology) The development and spread of various production technologies today is
The generation of wastewater is unavoidable during waste treatment, chemical processing, dyeing, and other manufacturing or processing processes, and these companies must purify such wastewater because it contaminates rivers, lakes, and oceans. Various research and developments have been carried out regarding processing. In other words, water pollution in rivers and other areas is mainly caused by wastewater from companies.
Since the wastewater discharged by each of the above-mentioned industries is the largest amount, all companies that generate such wastewater are considered to be benefactors, and therefore various technologies for purifying such wastewater are being studied. were piled up.

In other words, the use of microorganisms is the most natural and low-cost method for such purification treatment, and the treatment methods are broadly divided into floating suspension method and fixed biofilm method, and the former includes activated sludge method, , the aerated lagoon method, and the latter includes the contact aeration method.

(Problems to be Solved by the Invention) In any case, the conventional wastewater treatment equipment as described above is huge, has a large installation area, has poor responsiveness to load fluctuations, and has problems with the quality of treated water and sludge properties. There are disadvantages such as being easily influenced by fluctuations in

In particular, the huge size of the equipment and the large installation area may be useful for large companies, but the pollution in rivers and other areas today is largely caused by small companies and household wastewater, and such small companies Such equipment cannot be used in such areas. In particular, the recent rise in land prices has made it virtually impossible to employ this type of equipment, which requires at least several hundred units.

Furthermore, processing efficiency is not necessarily sufficient. In other words, the BOD volumetric load is used as an index to determine the capacity of such wastewater treatment equipment, and the BOD load (kg-BOD/day) is expressed as a unit of volume (kg-80 units/r+?・day). However, in the conventional standard activated sludge method and catalytic oxidation method, this BOD load is 0.35 to 0.8 kg-BOD/
rtr/day, and even in the rotating disk method and biofilter method, which are relatively expensive, the maximum
BOD/rd·day, and its processing efficiency is low.

Processing costs are high. In other words, in this type of wastewater treatment equipment, it is essential to supply oxygen and utilize the action of aerobic microorganisms, and the cost for this oxygen supply is approximately
It is determined by the amount of oxygen transferred per WH (kgOz/KW11), but it is 0.5 to 1 except for the ultra-deep aeration method and the surface aeration method.
．． 8 kgOz/KWH, and since the ultra-deep aeration method involves constructing an aeration tank with a water depth of 80 m or more, it requires an earthquake-resistant structure, which is extremely expensive, and the surface aeration method has problems with noise and droplets. and 2 due to foam scattering.
There are disadvantages such as secondary pollution, and in the end one has no choice but to use a method with a low amount of oxygen transfer, which inevitably has the drawback of increasing processing costs.

The construction period and cost for installation are large. In other words, as mentioned above, conventional devices that have to be large in size usually require several years to install, which naturally has the disadvantage of increasing construction costs.

In addition to the above, conventional systems have other drawbacks such as limitations in response to load fluctuations, amount of sludge generated, quality of treated water, etc., and difficulty in equipment modification and operation management.

"Structure of the Invention" (Means for Solving the Problems) 16 The wastewater to be treated is introduced into a rotating biological contact mechanism and an aeration tank, and is circulated to be sequentially treated, subjected to sedimentation treatment, and then discharged. wastewater treatment method.

2. It has a raw water tank that receives wastewater to be treated, a rotating biological contact mechanism, and an aeration tank, a raw water pump that sends the wastewater from the raw water tank to the rotating biological contact mechanism, and an aeration tank that transfers the treated water of the rotating biological contact mechanism. A wastewater treatment device characterized by being equipped with an outlet for supplying water to the wastewater.

3. Form a partition wall open at the bottom on one side of the aeration tank, introduce raw water into a regulating section divided by the partition wall, and supply the raw water from the regulating section to the rotating biological contact mechanism using a raw water pump. The wastewater treatment device according to item 1 above.

4. A measuring tank is provided in the raw water supply system from the raw water pump to the rotating biological contact mechanism, a return pipe is provided between the measuring tank and the aeration tank, and the raw water in the measuring tank is fed to the rotating biological contact mechanism under a constant head difference condition. The wastewater treatment device according to the above item 1, wherein the wastewater treatment device

(Function) In the rotating organism contact mechanism, colonizing microorganisms preferentially grow and grow to purify wastewater, and in the aeration tank, planktonic microorganisms preferentially grow and purify wastewater.

As described above, efficient wastewater purification is achieved by alternately applying purification through growth of colonizing microorganisms and planktonic microorganisms.

Forming a partition wall open at the bottom on one side of the aeration tank,
By introducing raw water into the regulating area divided by the partition wall, the aeration tank acts as a regulating tank.

By introducing raw water into the rotating biological contact mechanism through a measuring tank, a steady flow of raw water is introduced into the rotating biological contact mechanism.

(Example) To explain the specific embodiment of the present invention as described above, the present invention proposes to treat wastewater by circulating it through a rotating biological contact mechanism and an aeration tank mechanism. As mentioned above, by growing colonizing microorganisms such as filamentous fungi in the rotating biological contact mechanism and growing planktonic microorganisms in the aeration tank, efficient wastewater purification is achieved as a whole. It is something.

That is, an example of an apparatus for carrying out the method of the present invention is as shown in FIG. Raw water pipe 1 from the raw water pump 10
6 first supplies raw water to the screen 4, sieves out the foreign solids contained in the raw water, and passes it through the chute 17 to the receiver 4.
Accept it to 0. The raw water 41 that is under the sieve is transferred to the aeration tank 1.
For example, it is received in a regulating section 9 that is divided by a partition wall 8 that communicates with the bottom, and is connected to the rotating biological contact mechanism 2 through a circulation pipe 15 from a circulation pump 11 provided in the regulating section 9. It is supplied to the measuring tank 5 placed in front. In other words, while the raw water received in the raw water tank 3 is generally intermittent depending on the working conditions at the source, the contact treatment in the rotating biological contact mechanism 2 is constant, and a constant amount is always supplied through the measuring tank 5. However, given this relationship, the raw water that is supplied in large quantities per unit time is once received in the adjustment section 9 of the aeration tank 1 and raises the water level of the aeration tank 1. , is substantially prevented from flowing directly into the aeration tank 1 by the partition wall 8, and is sent into the metering tank 5 almost constantly by the circulation pump 11.

The same is true for the measuring tank 5 (the partition 51 is open at the bottom).
is provided, and a weir plate 52 is provided, and the raw water from the circulation pump 11 is supplied to one side of the partition 51, and a return pipe 53 is provided to the other side of the partition 51. Adjustment zone again for raw water supplied above the level! 19
The raw water that has overflowed beyond the weir plate 52 is constantly supplied to the rotating organism contact mechanism 2 with a certain head difference in the discharge chamber 54.

In the rotating living organism contact mechanism 2, a rotating body 21, the details of which are shown in FIG. However, as shown in Fig. 1, in such a mechanism 2, the raw water is stored at a water surface level slightly below the rotating shaft 24. That is, at such a water surface level, the rotating organism contact mechanism 2 There is an outlet 2 on the other side.
2 is provided, and the treated liquid from the discharge port 22 is returned to the other side of the aeration tank 1.

As shown in detail in FIG. 1 and FIG. 3, in the aeration tank 1, an aeration pump 12 is installed at the bottom of one side and discharges air to aerate the treatment liquid filled with the nuclide 1.
A discharge port 13 is provided on the other side of the aeration tank 1, and the sludge that has accumulated at the bottom is discharged through a valve opened by an electric or electromagnetic mechanism 13. It is designed to extract.

As is clear from Figure 1.3.4, in the case of this embodiment in which the rotating organism contact mechanism 2 is installed above the aeration tank 1, the height of the aeration tank 1 is generally 2 m or more, and therefore A deck plate is installed on top of the aeration tank 1, and a climbing ladder 19 is installed.
A handrail 19a and the like are provided so that the operator can check the operating status of the rotating organism contact mechanism 2, screen 4, etc. Furthermore, an operation panel 18 is provided on one side of the aeration tank l. It is designed to set its operating state and operate automatically.

As the rotating member 21 in the aeration tank 1, an appropriate disk-shaped rotating member can be adopted, but a preferred specific example based on practical research by the present inventors has a large specific surface area and a fixing property. In order to stably colonize filamentous fungi, which are microorganisms, and achieve high contact with raw water and air, we have adopted a three-dimensional module in which curled vinylidene chloride fibers are intertwined and the intersections of the fibers are adhered with a binder. In other words, the entire surface of the interlaced fibers is used as a colonization area for the microorganisms and also as a contact surface with air (oxygen), allowing efficient growth of filamentous fungi and purifying raw water. Finish processing.

The rotating body 21 has a diameter of 1000 to 1500 m.
is generally rotated within the rotating mechanism 2 at a speed of about 2 to 6 times/Ilin, thereby converting raw water (wastewater) and air (
Favorable contact with oxygen (oxygen) is achieved to create effective growth conditions for microorganisms, and even highly concentrated wastewater with a BOD of 6000 ppm or more can be efficiently treated.

It is clear that the number of colonizing microorganisms in the treated liquid that has been efficiently processed in the aeration tank 1 as described above is reduced, that is, this treated liquid is sent to the aeration tank 1 and aerated. This also increases the aeration efficiency. In other words, the growth of planktonic microorganisms is reduced because the treatment solution containing a high proportion of planktonic microorganisms is subjected to treatment in the aeration tank 1 under conditions in which the number of colonizing microorganisms is reduced and the treated solution with high planktonic microorganisms is less likely to be inhibited by colonizing microorganisms. Once the conditions are set, efficient aeration treatment results can be obtained.

The treated liquid in the aeration tank 1 as described above is transferred from the bottom of the partition wall 8 into the adjustment section 9, especially during times when the inflow of raw water from the raw water tank 3 has stopped, and is transferred to the circulation pump 11 and the metering tank. 5 to the rotating biological contact mechanism 2. That is, in the aeration tank 1, planktonic microorganisms tend to be abundant in the floating area on the liquid surface side of the aeration tank 1, and it is therefore presumed that colonizing microorganisms remain in the deep layer of the nuclide 1. The deep layer portion is sent again to the rotating organism contact mechanism 2, where it undergoes the above-mentioned contact treatment and the growth of colonizing microorganisms is attempted.

By repeating the above-mentioned treatments in sequence, each of the colonizing microorganisms and planktonic microorganisms can grow under conditions that minimize the interference caused by the presence of other microorganisms (therefore, the wastewater (purification), and as a result, a significantly more efficient treatment result can be achieved.

FIG. 5 summarizes an example of the operating process for standard food and other production equipment with a working time of 8 hours according to the present invention. In other words, the operation plan is based on the premise that during the working hours of the production equipment, wastewater is sequentially received and the rotating biological contact mechanism 2 is operated continuously for 24 hours for treatment. 2. Aeration pump 12 and solenoid valve 13 in aeration tank 1
This table shows the operational relationship between the raw water pump 10 and the operation of the raw water pump 10.
time, the circulation pump 11 and the rotating biological contact mechanism 2
starts at the same time as receiving this raw water, and the circulation pump 11
The system operates for about 20 hours after receiving raw water, and the rotating biological contact mechanism 2 continuously rotates for 24 hours. On the other hand, the aeration pump 12 starts after the raw water intake stops and pumps 200 liters depending on the BOD load amount.
Aeration treatment is performed by appropriately discharging air for about an hour.

This aeration may be continuous or intermittent, but after the aeration pump 12 is stopped, the aeration tank 1 will act as a settling tank, and after about 3 hours of settling time, the electric or solenoid valve is opened to release the water. .

A specific example of operation according to the present invention will be described below.

Operation example 1゜The composition of raw water, which is wastewater in a tofu manufacturing factory, has a pH of 6.
．． 6, 88 minutes is 1189■/kg, COD is 755,
4■/kg, BoD 1905■/kg, T-N 50
．． 0 mg/kg, and such raw water is supplied to the equipment shown in Figs. Growth of microorganisms was attempted alternately.

A summary of the average values of the results of hourly measurements of the sedimentation tank that received the discharged liquid from the outlet of the rotating biological contact mechanism 2 and the aeration tank 1, and the discharged liquid obtained by coagulating and filtering the discharged liquid from the sedimentation tank is shown below. As shown in Table 1 below, the BOD load is 57.2 kg-BOD/day (7) under operating conditions.
The OD removal rate reached 98%, which was confirmed to be an excellent result. Note that the mesh used as the screen 4 at this time was 100 mesh.

Table 1 Operation example 2゜ Wastewater from a pickle factory has a BOD load of 116.3 kg-B
OD/day, which is equivalent to twice the BOD load in Operation Example 1, so the equipment used in Operation Example 1 was
A 0.5 fl screen was used as the screen.

The pH of the wastewater is 5.6, SS is 42■/l, B
The OD was 1550/1, and this stock solution was supplied, and the average values of the measurement results at the outlet of the rotating biological contact mechanism and the settling tank at the aeration tank outlet were as shown in Table 2 below, as in Operation Example 1. Ta.

Table 2 Operation example 3゜The pH of wastewater from seafood processing equipment is 6.4, and SS
is approximately 4400■/1, BoD is approximately 3300ffv/1,
The COD was about 1800 .mu./f, and the treatment results for this wastewater were measured in the same manner as in Operation Example 1, and the results were as shown in Table 3 below.

Table 3 Operation Example 4 The present invention was adopted for wastewater from food preparation equipment. That is, the pn value of the wastewater is 5.4, and the ss is 178aw/
l, BOD is 1091+ng/j! The COD was 307 .mu./l, and the results obtained by applying the apparatus and method of the present invention to this wastewater in the same manner as in Operation Example 2 were as shown in Table 4 below.

Table 4, that is, when based on such operation results, BO in any case
It was confirmed that the D removal rate was 85% or more, reaching 98% in some cases, and it can be said that such a removal rate is much better than that in conventional equipment. Moreover, the area required to set up the equipment is approximately 10 - 10 square meters per unit, which is extremely small, less than a fraction of that of conventional equipment. In other words, it was of a scale that could be sufficiently applied to wastewater from small and medium-sized businesses, or domestic wastewater from households fishing on boats.

In addition, the oxygen transfer efficiency obtained from the above operation results was 2 to 4 kgOz/KWH, which is equivalent to the ultra-deep aeration method, and requires ultra-deep construction such as 80 m or more. It was confirmed that high processing efficiency could be obtained without using

Furthermore, when we calculated the BOD volumetric load, it was 7kg-BOD.
/rrr/day, and in some cases 18kg-
BO mouth/r+?・The traditional weight is generally 2 kg.
-BOD/d・Under daily income, maximum 3 kg-BOD/
I learned that the performance has been dramatically improved compared to those under rd/daily income.

``Effects of the Invention'' The method according to the present invention as explained above is capable of biologically carrying out efficient wastewater purification treatment, and therefore the equipment can be significantly downsized, making it suitable for large companies only. It can be used appropriately for small and medium-sized enterprises and living environment wastewater, and it can sufficiently reduce treatment costs for operation and operation, further reduce construction period and construction costs, and reduce noise and other problems. This invention has the effect of eliminating the causes of pollution, etc., and is a highly effective invention industrially.

[Brief explanation of the drawing]

The drawings show the technical contents of the present invention, and FIG. 1 is an explanatory diagram showing an overview of the device according to the present invention, FIG. 2 is a plan view of an example of the device of the present invention, and FIG. FIG. 4 is a partially cutaway side view of the same, FIG. 4 is a front view of the same, and FIG. 5 is a diagram of the operating process when the method of the present invention is adopted at a wastewater generation source of an 8 o'clock business. In these drawings, 1 is an aeration tank, 2 is a rotating biological contact mechanism, 3 is a raw water tank, 4 is a screen, 5 is a measuring tank, 6 is a drainage gutter, 7 is a sludge removal mechanism, 8 is a partition wall, and 10 is a Raw water pump, 11 is circulation pump, 12 is aeration pump, 1
3 indicates a solenoid valve. Patent applicant Kyokusui Planning Invention Co., Ltd.
Brother Tomohiro Ike /
fil. 4th m

Claims (1)

[Scope of Claims] 1. A wastewater treatment method characterized by introducing wastewater to be treated into a rotating biological contact mechanism and an aeration tank, circulating it, sequentially treating it, and subjecting it to sedimentation before discharging it. 2. It has a raw water tank that receives wastewater to be treated, a rotating biological contact mechanism, and an aeration tank, a raw water pump that sends the wastewater from the raw water tank to the rotating biological contact mechanism, and an aeration tank that transfers the treated water of the rotating biological contact mechanism. A wastewater treatment device characterized by being equipped with an outlet for supplying water to the wastewater. 3. Form a partition wall open at the bottom on one side of the aeration tank, introduce raw water into a regulating section divided by the partition wall, and supply the raw water from the regulating section to the rotating biological contact mechanism using a raw water pump. A wastewater treatment device according to claim 1, wherein the wastewater treatment device is configured to: 4. A measuring tank is provided in the raw water supply system from the raw water pump to the rotating biological contact mechanism, a return pipe is provided between the measuring tank and the aeration tank, and the raw water in the measuring tank is fed to the rotating biological contact mechanism under a constant head difference condition. The wastewater treatment mechanism according to claim 1, wherein the wastewater treatment mechanism is configured to feed wastewater.