KR100402900B1 - Operating method of single baffled reactor containing physically separated microorganism - Google Patents

Abstract

The present invention relates to a method of operating a single bulkhead type bioreactor capable of simultaneously treating contaminants using two kinds of spatially separated microorganisms. More specifically, the present invention relates to a method for biologically treating wastewater containing two or more kinds of inorganic ions, which are electron acceptors, in a single-walled bioreactor in which two kinds of microorganisms having different metabolism characteristics are spatially separated from each other.

By using the single bulkhead type bioreactor, the conventional ion exchange process for treating groundwater contaminated with nitrates can be innovatively used to reduce the amount of salt consumed in the regeneration of the ion exchange resin and to reduce the amount of waste liquid generated. In addition, the treatment of various wastewaters containing high concentrations of sulfates in the anaerobic digestion process has greatly helped to improve the stability of the process.

Therefore, if the method according to the present invention is applied, the operation cost of the existing ion exchange process can be greatly reduced, and it will contribute greatly to the health promotion and welfare of the residents of the farming and fishing villages using the small liver water supply facilities contaminated with nitrate nitrogen. Could be.

Description

OPERATING METHOD OF SINGLE BAFFLED REACTOR CONTAINING PHYSICALLY SEPARATED MICROORGANISM}

The present invention relates to a method of operating a single bulkhead type bioreactor capable of simultaneously treating contaminants using two kinds of spatially separated microorganisms. More specifically, the present invention relates to a method for biologically treating wastewater containing two or more kinds of inorganic ions, which are electron acceptors, in a single-walled bioreactor in which two kinds of microorganisms having different metabolism characteristics are spatially separated from each other.

In recent years, environmental problems caused by urban sewage and industrial wastewater due to the improvement of the standard of living and the high industrial development have emerged seriously. In general, municipal sewage and industrial wastewater contain large amounts of organic pollutants and nutrients, and standard activated sludge and anaerobic digestion are mainly used to remove organic pollutants. Among these methods, anaerobic digestion is mainly used for high concentration organic wastewater treatment because it can treat wastewater at low cost and recover methane, which is an alternative energy source.

Introduced in 1983 to treat organic industrial wastewater by anaerobic digestion, the ABR (anaerobic baffled reactor) can separate acid-forming bacteria from methane-forming bacteria in a reactor and operate as a two-phase anaerobic digestion system. Has the advantage. However, these relate to a method of treating wastewater having only one electron acceptor, and treatment of wastewater containing two or more kinds of electron acceptors has not been successful.

When organic wastewater containing high concentrations of sulfates is treated by anaerobic digestion, sulfate reducing bacteria using sulfates as electron acceptors generally compete with methane-forming bacteria and substrates. In general, when the reactor is operated at a medium temperature, most substrates are used by the sulfate-reducing bacteria because the sulfate-reducing bacteria are much more favorable in terms of kinetics than methane-forming bacteria. Therefore, methane-forming bacteria are inhibited by sulfides formed during sulfate reduction, thereby reducing the amount of methane gas that can be recovered. In order to solve the above problem, a method of artificially injecting heavy metals such as iron as a means for reducing the toxicity by sulfides has been studied (Dezham, P., Rosenblum, E., and Jenkins, D., " Digester Gas H ₂ S Control Using Iron Salts ", Journal of Water Pollution Ccontrol Federation, Vol. 60, No. 4, pp. 514-517, 1988), after desulfurizing the hydrogen sulfide from the reactor effluent and returning it to the influent. Measures to reduce the hydrogen sulfide concentration in the reactor have also been studied (see Yamaguchi, T., Harada, H., Hisano, T., Yamazaki, S., and Tseng, I., Process Behavior of UASB Reactor Treating Wastewater Containing High Strength). Sulfate ", Water Research, Vol. 33, No. 14, pp. 3182-3190, 1999).

However, when using the above two methods, the former has a problem of using a heavy metal which can be another source of contamination, and the latter adds an economic problem such as an increase in facility cost since the process needs to add another step.

On the other hand, the ion exchange process is widely used because it can selectively remove the specific cations or anions present in the water, and in particular, it has been spotlighted as a technology for the purification of groundwater for drinking water contaminated with nitrates. Normally, the nitrate exchange process is operated in the same cycle as service (groundwater treatment) → backwashing → regeneration → cleaning → service. In the regeneration process, high concentration (3 to 8%) of salt (NaCl) is used as regeneration solution. . When a resin having a depleted ion exchange capacity is reacted with a salt solution, anions (such as sulfate and nitrate) adsorbed on the resin are exchanged and removed by chlorine ions during the service process.

Therefore, high concentrations of sulfates and nitrates are present in the regeneration wastewater generated during the regeneration process. If the regeneration wastewater is discharged without proper treatment, secondary groundwater contamination or eutrophication of the discharged water is caused. Treatment is required.

The regeneration process in the ion exchange process is expensive enough to account for more than half of the total operating costs of the nitrate exchange process, because a large amount of salt is used to prepare the regeneration solution. In order to solve this problem, a method of biologically treating the recycled waste liquid and then reusing it as a regeneration agent has been studied. A study by van der Hoek, who denitrates nitrates from regenerated waste using an upflow sludge blanket reactor (USBR) reactor, and a regenerated waste liquid from a sequence batch reactor (SBR), was used. Clifford and Liu's work is a representative example (Clifford, DA, and Liu, X., "Ion exchange for Nitrate removal", J. AWWA , Vol. 27, No. 9, pp. 1477-1484, 1993). However, in these studies, only nitrates in the regenerated waste liquid were removed, and sulfates continued to accumulate, which greatly limited the number of times the regenerated waste liquid could be reused. The only nitrate removal from the bioreactor is because nitrates with high energy yield are preferentially used when nitrates and sulfates act as electron acceptors.

Therefore, in order to reuse the regeneration waste solution in which both nitrate and sulfate are present, the nitrate and sulfate must be reduced to nitrogen gas and hydrogen sulfide (H ₂ S) forms, respectively. In other words, because the energy yield of biological denitrification is relatively high, each group of microorganisms is treated separately in two reactors, or excessively provided with a carbon source (electron donor), so that the sulfate reduction reaction proceeds sufficiently in a single bioreactor. It should be possible. As a result, when biologically purifying wastewater containing two or more kinds of electron acceptors, it is necessary to use at least two reactors or provide an excessive carbon source, which in turn increases construction and operating costs.

Therefore, there is an urgent need for a more efficient processing method and apparatus while solving the above problems.

It is an object of the present invention to provide a method for biologically treating wastewater containing two or more types of inorganic ions, which are electron acceptors, in a single-walled bioreactor in which two microorganisms having different metabolism characteristics are spatially separated by a partition. .

1 is a block diagram of a bulkhead bioreactor for the treatment of regeneration wastewater generated in the nitrate exchange process for groundwater purification.

2 is a block diagram of a bulkhead reactor for treating organic wastewater containing high concentration sulfate.

Figure 3a and 3b is a graph showing the result of treating the nitrate and sulphate ion exchange process regeneration waste solution in a single bulkhead reactor separated from denitrifying bacteria and sulfate reducing bacteria 166 days.

Figures 4a and 4b is a graph showing the results of treating organic wastewater containing high concentration sulfate in a single-barrier reactor in which sulfate reducing bacteria and methane forming bacteria were separated for 338 days.

*** Explanation of symbols for main parts of drawing ***

10: bulkhead type bioreactor 11: first space part

12: second space portion 13: transition portion

14 head space 15 distribution device

16: pH sensor 17: discharge port

21: first inlet line 22: second inlet line

23: recycle line 24: first recycle line

25: second recycle line 26: effluent line

27 pump 28 check valve

31: first supply tank 32: second supply tank

33: first gas exhaust port 34: second gas exhaust port

35 collecting device 36: first collecting device

37: second collecting device 38: pH controller

41: sand filtration device 42: activated carbon adsorption device

43: Regeneration solution (treated water) storage tank 44: Salinity concentration measuring device

45: salt storage tank 46: supply regeneration liquid by ion exchange process

In order to achieve the above object, the present invention provides a method for biologically treating wastewater containing an inorganic ion, which is an electron acceptor, in a single-walled bioreactor in which two kinds of microorganisms having different metabolic properties are spatially separated into partitions. do.

More specifically, the present invention provides a plurality of transitions located between the plurality of spaces and the respective spaces, separated from the spaces immediately before by the weirs, and separated from the spaces immediately after the partitions with the bottom open. Using a single bulkhead type bioreactor consisting of parts, microorganism groups using inorganic ions having high energy yields as energy sources are sequentially inoculated into the space parts in order to form dominant species in each space part, and wastewater is continuously It relates to a biological treatment method of wastewater, characterized in that the operation by injection. The number of the space portions can be variously determined as necessary.

If there are two types of electron acceptors (inorganic ions) to be treated, a single-barrier bioreactor consisting of one transition part, a first space part immediately before the transition part and a second space part immediately after the transition part can be applied. have. For example, in order to treat wastewater containing nitrate and sulfate, a reaction tank having two space portions is applied, denitrifying bacteria are inoculated into the first space portion, and sulfate reducing bacteria are inoculated into the second space portion, respectively. Can be operated by injecting. At this time, since the pH changes according to the reaction in the first space portion, it is preferable to install a pH control device in the second space portion. As another example, in order to treat organic wastewater containing sulfate, the wastewater may be treated by inoculating sulfate reducing bacteria into the first space portion and methane forming bacteria in the second space portion.

In the present invention, it is preferable to add a carbon source (ethanol or methanol), a trace element, and a pH adjusting agent to the growth of microorganisms in all or part of the respective space parts in order to increase the efficiency for wastewater treatment.

Meanwhile, various types of gases may be generated in the upper part of each space part of the partition-type bioreactor applied to the present invention according to wastewater treatment. Therefore, it is desirable to further install a device that can safely collect and discharge the generated gas.

The single bulkhead bioreactor of the present invention comprises (i) an anaerobic single bulkhead bioreactor with different microbial groups predominantly at the front and rear ends: (ii) ancillary equipment such as a wastewater feeding pump: Include a recycle line applied to increase the processing efficiency in each step.

A system suitable for carrying out the above process is fabricated using not only the single bulkhead bioreactor described in the present invention, but also conventionally known anaerobic baffled reactors, pumps, piping and related plant microorganisms. This is possible. The single-barrier bioreactor of the present invention for the treatment of the regeneration wastewater generated in the nitrate exchange process can be utilized for the regeneration of the ion exchange resin for relatively small size groundwater treatment, and can be fixed and installed in addition to the groundwater treatment system. In addition, in order to further reduce the fixed cost, it is also possible to drive to the required place after installation in the vehicle.

Method 1 : Treatment of Nitrate Exchange Recycling Waste Using Single Bulkhead Bioreactor

The present invention relates to a method for treating regenerated waste liquid in a nitrate exchange process in which two or more kinds of electron acceptors are present.

Instead of using a conventional bioreactor for treating the waste liquid, a single bulkhead bioreactor produced by the present invention is used. The partition wall is divided into a single reactor 10 and a first space 11 and a second space 12, and a transition part 13 is placed in the center so that bacteria in the two spaces do not mix with each other. Then, the head space (14) of the vacuum state is placed on the top of the reaction tank so that the space portion and air do not directly contact.

The first space 11 is planted with a predetermined amount (4 liters) of sewage sludge collected from an activated sludge tank in a sewage treatment plant, and the digested sludge collected from a sewage treatment plant (4 liters) is planted with a second space portion 12.

Ethanol is added as a carbon source to the regeneration wastewater containing sulfate and nitrate, and trace elements (ammonia nitrogen, phosphorus, calcium, etc.) necessary for the growth of microorganisms are added. The input of carbon source ethanol and each trace element is calculated based on information reported in the literature (Van der Hoek, JP, Latour, PJM, and Klapwijk, A., “Denitrification with Methanol on the Presence of High Salt Concentration and High pH Levels ”, Appl. Microbiol. Biotechnol. , Vol. 27, pp. 199-205, 1987). The substrate prepared as described above is stored in the first supply tank 31, and the system is operated by allowing the substrate to enter the first space 11 during the operation of the bioreactor.

When the nitrate is removed from the first space 11, the pH in the water increases, so the pH of the sulfate reduction unit should be maintained in an appropriate range (pH 6.5 to 8.5). Therefore, the pH sensor 16 is installed on the upper part of the transition part 13 and the upper part of the second space part 12, and monitored using the pH controller 38. The pH adjusting liquid is stored in the second supply tank 32 so that the pH adjusting liquid can be injected into the intermediate portion of the transition part 13, and the pH adjusting liquid is installed in the second inflow line 22 to automate pH adjustment. It is preferable.

The waste liquid passing through the transition part 13 finally flows into the second space part 12, and the sulfate is reduced to hydrogen sulfide by the sulfate reducing bacteria. Hydrogen sulfide is exhausted through the second gas exhaust port 34 and then collected in the collecting device 35. The effluent may be recycled through the recirculation line 23 to increase the sulfate removal efficiency of the second space 12.

In addition, a line is installed so that each space portion and devices are connected to each other to allow the waste water to pass through, and a gas exhaust port and a collecting device for treating nitrogen gas and hydrogen sulfide generated during waste water treatment are installed (FIG. 1).

The final effluent discharged after the treatment in the reaction tank may be discharged as it is, or may be treated once more through the following apparatus for reuse as a regeneration solution of the ion exchange resin. That is, the remaining water may be further removed by passing the effluent water of the second space part 12 in the order of the sand filtration device 41 and the activated carbon adsorption device 42.

On the other hand, for the regeneration solution or the regeneration solution in which impurities are further removed, the salinity concentration of the regeneration solution is measured by the salt concentration measuring device 44, and if necessary, the salt is replenished from the salt storage tank 45 to obtain an appropriate concentration (3 to 3). 8%), and then reused as the ion exchange resin regeneration solution.

The post-treatment process uses a method (Application No. 10-2000-0023180, “Regeneration treatment method of ion exchange resin regeneration waste liquid”) filed by the present inventors.

Method 2 : Treatment of Sulfate Wastewater by Single Anaerobic Bulkhead Bioreactor

Organic wastewater containing high concentrations of sulfates is treated using a single-barrier bioreactor (10) in which the sulfate reducing bacteria (SRB) and methane producing bacteria (MPB) are spatially separated. It is about.

The same bioreactor 10 as used in Method 1 is used.

The sulfate (SO ₄ ^2- ) is reduced to hydrogen sulfide (H ₂ S) by the sulfate reducing bacterium in the first space part 11, and then exhausted from the first gas exhaust port 33 after passing through the first collecting device 36. do. In order to improve the sulphate removal rate, the effluent of the first space 11 may be recycled through the first recycle line 24 at the upper portion of the transition unit 13.

Wastewater from which the sulfate is removed from the first space portion 11 passes through the transition portion 13 and flows into the second space portion 12. In order to increase the activity of methane-forming bacteria, the second space 12 effluent may be recycled through the second recycle line 25 or a separate organic wastewater may be injected from the second supply tank 32. Methane gas (CH ₄ ) generated in the second space portion 12 is discharged through the second gas exhaust port 34, and then collected in the second collecting device 37.

The final effluent purified through the single bulkhead bioreactor 10 may be treated and discharged in the same manner as the final effluent subsequent treatment of Method 1.

Sewage digestion sludge (10000 to 12000 mg MLVSS / L) in a predetermined amount (3 to 4 L) is planted in the first space 11 and the second space 12 in the reactor. In general, digested sludge contains a large amount of methane-forming bacteria and sulfate reducing bacteria, so digested sludge may be used as a planting microorganism in each space. The system is operated while injecting the sulfate-containing organic wastewater stored in the first feed tank 31 into the first space 11 through the first inlet line 21 at an appropriate flow rate.

Hereinafter, the embodiment will be described in more detail. These examples are only for illustrating the present invention in more detail, it will be apparent to those skilled in the art that the scope of the present invention is not limited to these examples.

Example 1 : Treatment of Regenerated Wastewater from Nitrate Exchange Using Single Bulkhead Reactor

A single bulkhead bioreactor was used to treat the nitrate exchange regeneration wastewater containing two or more types of electron acceptors.

Instead of using a conventional bioreactor for treating the waste liquid, a single bulkhead bioreactor manufactured by the present invention was used. A single reactor is divided into a first space portion (hereinafter referred to as denitrification portion) and a second space portion (hereinafter referred to as sulfate reduction portion in this experiment), and a transition portion is placed in the center so that the bacteria in the two space portions are separated from each other. It was not mixed. And, the head space (head space) is placed on the top of the reaction tank to prevent the bio-gas (bio-gas) generated in each space portion to mix with each other. The effective capacity of the denitrification unit and the sulfate reduction unit was 5 L, the effective capacity of the transition unit was 4 L, and the head space was 3 L, respectively. In the denitrification unit, 4 L of sewage sludge collected from the activated sludge tank of Daejeon was planted, and 4 L of digested sludge collected from the sewage treatment plant was planted in the sulfate reduction unit.

The substrate prepared by adding ethanol and a trace element to the regeneration wastewater containing sulphate and nitrate was stored in the first feed tank, and introduced into the denitrification unit during the operation of the bioreactor. The bioreactor was operated at 25 ° C. with varying loading rates in nine steps for a total of 166 days.

In order to operate the reactor more efficiently, the following accessory device was installed.

A pH sensor was installed at the top of the transition part and the sulfate reduction part to confirm the increase in pH by removing nitrate from the denitrification part, and the pH was monitored using a pH controller so as not to exceed the proper range (pH 8.5). In addition, in order to inject the pH adjustment liquid in the intermediate portion of the transition portion, the pH adjustment liquid was stored in the second supply tank, and the pH adjustment liquid was allowed to flow in the second inflow line to automate pH adjustment.

In addition, lines were installed so that the spaces and devices were connected to each other to allow the wastewater to pass through, and a gas exhaust and a collecting device for collecting nitrogen gas and hydrogen sulfide generated during wastewater treatment were installed (FIG. 1).

Nitrate in the waste solution is playing the denitrification reaction in the denitration unit is reduced to nitrogen gas by _{^{(NO 3 - - → NO 2}} → N 2), a waste solution of a nitrate treatment via transition portion flows portion sulfate reduction. At this time, the generated nitrogen gas is discharged through the first gas exhaust. As a result, dissolved oxygen and oxidation-reduction potential in the regeneration waste liquid are reduced, which is advantageous for sulfate reducing bacteria. In the sulfate reduction unit, the sulfate is reduced to hydrogen sulfide by a sulfate reduction reaction (SO ₄ ^2- → H ₂ S), and the hydrogen sulfide is discharged through the second gas exhaust and collected in the collecting device. The recycled waste liquid thus treated was passed through the sulphate reducing unit again through the effluent line to increase the efficiency of removing the sulfate.

Table 1 summarizes the conditions under which the bioreactor was operated for 166 days to treat the regeneration wastewater under the above conditions. The nitrate concentration of the denitrification effluent was measured at the top of the transition part, and the sulfate concentration of the sulphate reduction effluent was measured at the top of the sulfate reduction part.

The operation was carried out continuously in a total of nine stages, with different flow rates and influent concentrations.

In stage 1 (runs 1-19), the nitrate load was operated at 1.9 g NO ₃ ^-- N / l.day, and the denitrification rate and COD removal rate were continuously monitored with increasing load. The initial sulfate load of the sulfate reduction unit was 0.7 g SO ₄ ^2- / l · day and the load was changed at the same time as the denitrification unit. With this method of operation, the maximum nitrate load of 5.4 g NO ₃ ^-- N / ℓ · day was applied in step 9 for the denitrification part, and the maximum sulfate load 3.5 g SO ₄ ^2- / ℓ · day in step 6 for the sulfur sulfate source part. Applied.

The results of the treatment of recycled waste liquid by the present experimental method are as follows.

As shown in FIG. 3a, the nitrate removal rate (denitrification rate) of the denitrification part was only about 70% since the planting microorganism was not completely adapted to the substrate in step 1, but the nitrate removal rate of the denitrification part was maintained at 90% from the second step. The nitrate removal rate was increased to 96% in the 9th stage with the maximum nitrate load of 5.4 NO ₃ ^-- N / ℓ · day. Comparing the sulfate concentration of the raw water and the denitrification effluent of Figure 3b, it can be seen that the sulphate reaction did not proceed in the denitrification unit.

Meanwhile, in the sulfate reduction unit of FIG. 3B, the sulfate reduction rate was low until step 2, but the sulfate reduction reaction proceeded dominantly from step 3 to achieve a sulfate reduction rate of 50% or more.

As can be seen from the above results, the treatment of the ion exchange resin regeneration wastewater using a single-barrier bioreactor in which the denitrification bacteria and the sulfate reduction bacteria were spatially separated resulted in high efficiency (90% and 50% or more) can be effectively treated.

Example 2 Treatment of Sulfate Wastewater Using a Single Anaerobic Bulkhead Bioreactor

A single bulkhead bioreactor was used to treat wastewater containing high concentrations of sulfate.

The same bioreactor as in Example 1 was used to treat the waste liquid.

However, the pH sensor and controller were removed because there is no need to adjust the pH (FIG. 2).

When the wastewater flowed into the first space portion (hereinafter referred to as sulfate reduction portion), the sulfate was reduced to hydrogen sulfide by a sulfate reduction reaction (SO ₄ ^2- → H ₂ S). Hydrogen sulfide was collected in a collecting device after discharged through the first gas exhaust. The recycled waste liquid thus treated was passed through the sulphate reduction unit again through the effluent line to increase the efficiency of removing the sulfate.

The effluent from which sulfate was removed flows into the second space portion (hereinafter referred to as methane forming portion) through the transition portion, and methane gas is generated by the methane forming bacteria. Methane gas was discharged through the second gas exhaust and then collected in the second collecting device.

In Daejeon, 3.5 L of sewage digestion sludge (11,100 mg MLVSS / L) was planted in the sulfate reduction unit (2), and 5 L of the same digested sludge was planted in the methane forming unit (4). Artificial wastewater was made using industrial glucose and Na ₂ SO ₄ , and COD and sulfate (SO ₄ ^2- ) removal rates were monitored in each space part by changing the loading rate in 8 steps for a total of 338 days.

Table 2 summarizes the conditions under which the bioreactor was operated for 338 days using the sulfate-containing organic wastewater artificially prepared under the above conditions. Sulfate concentration and COD concentration of the sulphate reduction effluent at the upper part of the transition part were measured, and sulfate concentration and COD concentration of the effluent of the methane forming part were measured at the top of the methane forming part.

Ratio of 0.9 SO ₄ ^2-:: 0.8, methane formation section COD: the COD step sulfate-reducing portion ratio of SO ₄ ^2- 0.6: To start the operation at 0.5. In order to increase the activity of methane-forming bacteria which are relatively slow in growth and more sensitive to environmental changes, the treated water of the methane-forming part was recycled until the second stage. In addition, after the third step, the COD load was increased by additionally injecting a separate substrate made of industrial glucose into the methane forming unit. In the final eight steps, the COD load applied to the methane forming unit amounted to 8.2 g COD / l · d.

The results of the treatment of wastewater containing high concentration of sulfate by this test method are as follows.

4A and 4B, the COD and SO ₄ ^2- concentrations of the sulphate-reduced effluent were maintained relatively high at the initial stage of operation (up to mid 70 days), but the COD and SO ₄ ^2- removal rates of the sulphate-reduced portion were very high thereafter. Good levels were seen. Most of the sulfate in the raw water was removed from the sulfate reduction section. In the case of methane formation, the COD concentration of the effluent was kept below 250 mg / l, although a maximum substrate load of 8.2 g COD / l · d was applied due to the separate substrate supply. This may be due to the fact that methane-forming bacteria in the methane-forming part were hardly affected by the toxicity of hydrogen sulfide (H ₂ S), the final product of the sulfate reduction reaction. This result is impossible to achieve with other single reactors in which the microbial population is not spatially separated.

Therefore, the treatment process developed in the present invention is shown to be very effective for the treatment of wastewater containing multiple pollutants, such as the wastewater in the present invention.

As described and demonstrated in detail above, the present invention relates to a method for biologically treating a wastewater containing a large number of inorganic ions, which are electron acceptors, in a single-walled bioreactor in which two kinds of microorganisms having different metabolism characteristics are spatially separated. will be.

By using the single bulkhead type bioreactor, the conventional ion exchange process for treating groundwater contaminated with nitrates can be innovatively used to reduce the amount of salt consumed for the regeneration of the ion exchange resin and to reduce the amount of waste liquid generated. In addition, the treatment of various organic wastewaters containing high concentration of sulfate by anaerobic digestion process greatly helped to improve the stability of the process.

Therefore, if the method according to the present invention is applied, the operation cost of the existing ion exchange process can be greatly reduced, and it will contribute greatly to the health promotion and welfare of the residents of the farming and fishing villages using the small liver water supply facilities contaminated with nitrate nitrogen. Could be.

Claims (6)

In the method of biologically treating wastewater containing two or more kinds of inorganic ions that can act as electron acceptors, A single bulkhead type bioreactor consisting of a plurality of space portions and a plurality of transition portions located between each space portion and separated from the immediately preceding space portion by a weir, and separated from the immediately spaced portion by a partition wall having an open lower portion. By using, the microbial group using inorganic ions with high energy yield as an energy source is sequentially inoculated into the space part in order to form a dominant species in each space part, characterized in that to operate by continuously injecting wastewater Biological treatment method of wastewater to be. The method of claim 1, The single bulkhead bioreactor comprises one transition portion, a first space portion immediately before the transition portion and a second space portion immediately after the transition portion. The method of claim 2, A method for biological treatment of wastewater, comprising inoculating denitrifying bacteria in the first space portion and sulfate reducing bacteria in the second space portion for treatment of wastewater containing nitrate and sulfate. The method of claim 3, wherein The second space portion is biological treatment method of wastewater, characterized in that additionally installed a pH control device. The method of claim 2, For the treatment of organic wastewater containing sulphate, the first space portion is inoculated with sulfate reducing bacteria, the second space portion methane forming bacteria, characterized in that the biological treatment method of wastewater. The method according to any one of claims 1 to 5, In order to increase the efficiency of the operation, the biological treatment method of the wastewater, characterized in that for recycling all or part of the treated water flowing out of the respective space portion.