JPS62237996A - Apparatus for treating waste water - Google Patents

Abstract

PURPOSE:To obtain good quality treated water through efficient treatment, by mounting a culture tank and an apparatus for obtaining immobilized microorganism. CONSTITUTION:A part of raw water 8 is guided to a culture tank 1 and bacteria corresponding to the components of raw water are collectively cultured and a culture solution 13 is guided to a sedimentation tank 2. Conc. microorganisms are sent to a microorganism immobilizing tank 3 to prepare immobilized microorganism which are, in turn, supplied to a first stage treatment reactor 4, a second stage treatment reactor 5 and a final stage treatment reactor 6 while separated water 9 is returned to raw water flowing in the treatment reactor 4. A part of raw water is made to flow in the culture tank 1 and proper bacteria corresponding to the components of waste water containing the org. components in raw water as a main substrate are collectively cultured. Subsequently, conc. microorganisms 14 are sent to the immobilized tank 3 and enclosed in the polymer supplied from a polymer tank 5 to obtain immobilized microorganisms.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a wastewater treatment device using immobilized microorganisms.

(Prior Art) The activated sludge method is the most popular method for treating urban sewage and organic industrial wastewater. However, in this activated sludge method, the concentration of microorganisms per volume of the treatment device is low and the treatment time is long, so the device becomes large and requires a vast area. Further, there are many problems such as bulking development often occurring in the solid-liquid decomposition step after treatment and a large amount of surplus sludge being generated. On the other hand, fixed-type processing devices have been considered in which microorganisms are attached to various carriers, and the immersion hearth method, the rotating disk method, and the like have been put into practical use. These utilize the phenomenon of microorganisms naturally adhering to the surface of a carrier and forming a film, and it is possible to maintain a high concentration of microorganisms per volume of the processing equipment, and the processing equipment can also be made smaller. Further, if the treatment is carried out stably, solid-liquid separation is also easy. However, due to aging of microorganisms, fluctuations in the quality of treated water, etc., the biofilm may peel off or it may become difficult to generate a biofilm, making maintenance management difficult.

On the other hand, in the fields of pharmaceutical manufacturing and the fermentation industry, a bioreactor method has been developed in which microorganisms are immobilized in a resin or the like and made into pellets or membranes, and in recent years they have also begun to be adopted in the field of wastewater treatment. In this method, microorganisms are cultured in advance at a high concentration and immobilized, so it is possible to arbitrarily increase the microorganism concentration to a certain degree.

Furthermore, immobilization stabilizes biological activity and increases the processing temperature and pH.
etc. may have a wider tolerance range. Furthermore, since the bacterial cells are immobilized, solid-liquid separation is easy. therefore,
It is characterized by the fact that it can be processed in a short time using a small processing device.

(Problems to be solved by the invention) The microorganisms to be immobilized are concentrated activated sludge obtained from general sewage treatment plants, or activated sludge is used as a seed sludge and cultured in any artificial medium and separated. By operation,
Highly concentrated microorganisms can be obtained.

In this case, if the composition of the wastewater to be treated differs from the composition of the artificial medium in which the microorganisms were cultured, sufficient treatment efficiency may not be obtained.

Furthermore, the treatment efficiency may also decrease when the quality of the wastewater to be treated changes. Furthermore, if the wastewater to be treated contains harmful substances or difficult-to-decompose substances, the treatment efficiency will be significantly reduced.

On the other hand, alginic acid, k-carrageenan acrylamide, photocurable resin, etc. are known as immobilization carriers.
When microorganisms are immobilized, the carrier has sufficient strength, but as processing time progresses, the carrier swells due to the growth of microorganisms, gases generated through metabolism, and the effects of components in wastewater, and eventually collapses. Sometimes. As a result, free microorganisms and carrier fragments may flow out into the treated water, deteriorating the quality of the treated water.

An object of the present invention is to provide a wastewater treatment device using immobilized microorganisms that solves the problems of the prior art, efficiently processes wastewater to be treated, and provides high-quality treated water regardless of the quality of the wastewater. It's about doing.

(Means for Solving the Problems) That is, the present invention introduces a portion of raw water, uses the organic components in the raw water as the main substrate, and cultivates suitable microorganisms corresponding to the raw water components at a high concentration. an apparatus for separating the obtained microorganisms and obtaining concentrated microorganisms and separated water;
The present invention is a wastewater treatment device comprising a device for entrapping and immobilizing the obtained concentrated microorganisms to obtain immobilized microorganisms, supplying the immobilized microorganisms to a treatment reactor, and returning the separated water to the first treatment reactor.

(Operation) Next, the operation of the present invention will be explained in detail according to the drawings.

FIG. 1 is a configuration diagram showing an example of a wastewater treatment apparatus according to the present invention. In the present invention, a part of the raw water 8 is introduced into the culture tank 1, and appropriate microorganisms corresponding to the components of the raw water are enriched and cultured.
The obtained culture solution 13 containing microorganisms at a high concentration is led to the sedimentation separation tank 2, where the culture solution is sedimented and separated to obtain concentrated microorganisms 14 and separated water 9. The concentrated microorganisms are sent to the microorganism immobilization tank 3 to produce immobilized microorganisms. The obtained immobilized microorganisms are supplied to the first stage treatment reactor 4, the second stage treatment reactor 5, and the third stage (final stage) treatment reactor 6, and the separated water 9 is returned to the raw water flowing into the treatment reactor. Ru. The first feature of the present invention is that it includes each of the above devices. A portion of the raw water 8 is flowed into the culture tank 1, where appropriate microorganisms corresponding to the components of the wastewater are enriched and cultured using the organic components in the raw water as a main substrate. In addition, as necessary, substrates such as glucose and acetic acid, nitrogen to help culture microorganisms, phosphorus inorganic salts, yeast extract, etc.
It may also be supplied from the nutrient tank 7. The microorganisms to be inoculated initially may be general municipal sewage treatment sludge or industrial wastewater treatment sludge, but if the wastewater to be treated is used in advance,
If microorganisms cultured on a small scale are used, a rapid start-up can be expected. In addition, if the raw water contains a non-degradable substance, an appropriate amount of the non-degradable substance is introduced into the culture tank from the nutrient tank 7, and a special strain of bacteria that decomposes the non-degradable substance is added. By inoculating the culture tank 1, it is possible to deal with wastewater containing difficult-to-decompose substances. The conditions for cultivating the microorganism in the culture tank 1 vary depending on the microorganism, but in general, it is desirable that the temperature be 25 to 35 degrees Celsius and the pH be 6 to 8. In addition, in the case of aerobic conditions, aeration is performed with air, oxygen, etc., and dissolved oxygen is supplied. The culture solution 13 that has been enriched and cultured in the culture tank 1 flows into the sedimentation separation tank 2 . In the sedimentation separation tank 2, the culture solution 13 is left standing and the separated water 9
and concentrated microorganisms 14. In order to carry out separation, it is desirable that the microorganisms contained in the culture solution 13 coagulate and settle in the form of activated sludge by standing still, and therefore a part of the concentrated microorganisms 14 is returned to the culture tank 1. By repeating this operation, the number of microorganisms settling in the culture tank 1 increases, and as a result, the concentration of microorganisms in the culture tank increases. The separated water 9 produced in the settling tank 2 mixes with the raw water 8 and flows into the treatment reactor.

Next, the concentrated microorganisms 14 obtained in the sedimentation separation tank 2 are sent to the immobilization tank 3. Here, the microorganisms are incorporated into the polymer supplied from the polymer tank 15 to obtain immobilized microorganisms. Currently, natural polymers such as alginic acid, k-carrageenan, agar, gelatin, and albumin, and synthetic polymers such as acrylamide and photocurable resins are known as polymers used for immobilization. Any polymer may be used. Further, depending on the manufacturing method, the shape of the immobilized microorganism can be formed into pellets, sheets, fibers, etc., and this can be arbitrarily selected depending on the structure of the processing reactor. The concentrated microorganisms 14 are mixed with polymers supplied from the polymer tank 15 in an arbitrary ratio, and then transferred to the immobilization tank 3.
to perform the immobilization reaction. The surface of the obtained immobilized microorganism has many micropores, and components in the raw water pass through these micropores and diffuse inside. On the other hand, since the microorganisms immobilized inside cannot pass through the micropores, they are retained in the carrier while metabolizing and decomposing components in the diffused raw water that are difficult to leak to the outside.

As mentioned above, the concentration of microorganisms in immobilized microorganisms can be arbitrarily selected depending on the loading amount of raw water, and physical stability can be obtained by being encapsulated in polymers, and the buffering effect of polymers etc., the applicable temperature range and pH range are often widened. The obtained immobilized microorganisms are supplied to a processing reactor. Various structures have been proposed for bioreactors using immobilized microorganisms and immobilized enzymes. Fixed bed systems include packed bed type, model, pipe wall, and plate type, and fluidized bed systems include particle dispersion type and plate type. Furthermore, an ultrafiltration membrane type in combination with a separation membrane has also been devised. Immobilized microorganisms have sufficient strength immediately after the immobilization reaction, but as processing time progresses, the carrier expands due to the proliferation of microorganisms, gases generated by metabolism, and the effects of components in the raw water, and eventually collapses. There is. Therefore, multiple processing reactors can be connected and 8
! >'I+ By performing the treatment, the amount of load applied to the downstream processing reactor is reduced, the expansion of the carrier in the downstream processing reactor is reduced, and the free microorganisms and debris of the carrier that flow in from the upstream stage are removed from the downstream stage. An effective method is to capture it in a processing reactor.

As a second feature of the present invention, when supplying immobilized microorganisms to the processing reactor, the above-mentioned points are taken into account, and the deteriorated immobilized microorganisms in the first stage processing reactor are discarded and the immobilized microorganisms are sufficiently strong immediately after immobilization. At the same time, this processing reactor is used as the final processing reactor, and the second
An example of this is to sequentially shift the inflow order so that the stages after the stage processing reactor are positioned one stage forward.

FIG. 1 is an example of a three-stage process in which three process reactors are connected. At the start of the treatment, the raw water 8 flows into the No. 1 treatment reactor 4, which is the first stage treatment reactor, and most of the components to be treated are treated here. Next, the second stage processing reactor No. 2 processing reactor 5
Finally, the final stage processing reactor, No.
, 3 into the treatment reactor. In the second and final stage treatment reactors, components to be treated that could not be treated in the first stage are treated and discharged as treated water 12. No. 1, which takes the largest amount of load as processing time progresses
The immobilized microorganisms in the treatment reactor 4 begin to deteriorate, expand, and disintegrate, and free microorganisms, carrier fragments, and the like come to be mixed into the effluent water. However, while passing through the No. 2 treatment reactor 5 and the No. 3 treatment reactor 6, free microorganisms, carrier fragments, etc. are captured, and the treated water 12
water quality will not deteriorate. When the deterioration of the immobilized microorganisms in the N091 treatment reactor 4 becomes severe, the immobilized microorganisms inside are discarded and the new, freshly immobilized, sufficiently strong one obtained in the immobilization tank 3 is used. Fill with immobilized microorganisms. At this point, change the inflow route of raw water 8 and first
, flows into the two-process reactor 5. Next, it flows into No. 3 processing reactor 6, and finally No. 1 processing reactor 4.
and is discharged as treated water 12. No here,
The 2-processing reactor 5 supplies NO to the 1st-stage processing reactor.
63 processing reactor 6 becomes the second stage processing reactor, N
o, 1 processing reactor 4 has been sequentially shifted to the final stage processing reactor.

Similarly, when the immobilized microorganisms in the No. 2 treatment reactor 5 deteriorate, the deteriorated immobilized microorganisms are discarded and the newly obtained immobilized microorganisms are filled, and the raw water 8
flows into No. 3 processing reactor 6, and then No. 1
The water flows into the treatment reactor 4, and finally flows into the No. 2 treatment reactor 5, where it is discharged as treated water 12.

As mentioned above, the degraded immobilized microorganisms are discarded and the treatment reactor filled with the newly obtained immobilized microorganisms is used as the final stage treatment reactor to prevent deterioration of the quality of the treated water, and as the second stage treatment reactor. Effective treatment can be carried out by using a processing reactor that carries an appropriate load, the microorganisms in the carrier proliferate, and the activity of the immobilized microorganisms increases as the first stage processing reactor. Each processing actor
Although a small amount of surplus sludge 11 is generated, a portion is returned to the culture tank 1 as return sludge 10, and the rest is discharged outside the system.

(Effects of the Invention) As detailed above, according to the present invention, the following effects can be obtained.

(1) By performing enrichment culture of microorganisms using components in wastewater as the main substrate, immobilized microorganisms suitable for the components in wastewater can be obtained, and by supplying them to the treatment reactor as needed, the effect can be improved. processing can be performed.

(2) It can respond to fluctuations in the quality of wastewater and to wastewater containing difficult-to-decompose substances.

(3) By using the treatment reactor filled with new immobilized microorganisms as the final stage, floating microorganisms, carrier fragments, etc. that flow in from the previous stage can be captured, and the quality of the treated water is good.

(4) Since a high concentration of immobilized microorganisms is used, the device is small and does not require a large area even if multistage processing is performed.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an example of a device according to the present invention. In the figure, 1: Culture tank 2: Sedimentation tank 3: Immobilization tank 4: 1st stage processing reactor 5: 2nd stage processing reactor 6: 3rd stage processing reactor
Stage treatment reactor 7: Nutrient tank /: Cultivation tank 2: Sedimentation separation tank 3: Fixed tank φ2 171 feet 44 feet reactor: Tan 11 medium bamboo 8': Log polymer grain

Claims (2)

[Claims] (1) In a wastewater treatment device that connects a plurality of treatment reactors filled with immobilized microorganisms and performs multistage treatment, a culture tank that allows a portion of the raw water to flow in and accumulates and cultivates the microorganisms;
It is equipped with a device that separates the microorganisms that have been enriched and cultured into concentrated microorganisms and separated water, and a device that comprehensively immobilizes the concentrated microorganisms to obtain immobilized microorganisms, and returns the separated water to the first stage treatment reactor to remove the immobilized microorganisms. A wastewater treatment device characterized by supplying wastewater to a treatment reactor. (2) In the supply of the immobilized microorganisms, when discarding the deteriorated immobilized microorganisms in the first stage processing reactor and filling with new immobilized microorganisms, the first stage processing reactor is changed to the final stage processing reactor,
2. The wastewater treatment apparatus according to claim 1, wherein the order in which wastewater flows into the treatment reactor can be changed so that the second stage treatment reactor and subsequent stages are positioned one stage upstream.