KR20230101555A - An eco-friendly recirculating and filtering integrated aquaculture system based on salinity tolerant aerobic granular sludge and microalgae - Google Patents

Abstract

The present invention relates to an eco-friendly circular filtration complex aquaculture system based on salt-resistant aerobic granular sludge and microalgae for the zero-discharge circular use of cultured water in fish farms. More specifically, provided is a system in which a membrane separation tank inoculated with the salt-resistant aerobic granular sludge is operated as a sequencing batch reactor (SBR) to efficiently process organic matter and ammonia nitrogen generated from feed residues and waste products generated during a shrimp and cockle farming process, remaining nitrate nitrogen is consumed by microalgae, and increased microalgae biomass is provided as a food source for cockles. According to the present invention, an environmentally friendly and efficient aquaculture system can be provided.

Description

An eco-friendly recirculating and filtering integrated aquaculture system based on salinity tolerant aerobic granular sludge and microalgae}

The present invention relates to a salt-resistant aerobic granular sludge and microalgae-based eco-friendly circulating filtration complex aquaculture system for non-discharge circulation use of aquaculture water in fish farms, and more particularly, to a continuous batch reactor using a membrane separator inoculated with salt-resistant aerobic granular sludge (Sequencing Bactch Reactor, SBR) to efficiently treat organic matter and ammonia nitrogen generated from feed scraps and wastes generated during the shrimp and cockle farming process, and microalgae consume the remaining nitrate nitrogen and increase the microalgae It relates to a system that provides algal biomass as a food source for cockles.

The festival fish farm is a form of managing water quality by relying on a running water system that continuously flows seawater and farmed water from the shore. During the farming period, feed residues, green algae, and waste products discharged from fish farming accumulate, resulting in organic matter and ammonia nitrogen in the farming water. Farmed fish grown in such harsh environments are very vulnerable to disease, leading to mass mortality. In festival fish farms, chemicals such as antibiotics, biocides, and water quality improvers are excessively injected to prevent mass death of fish, so there is a high possibility that substances harmful to the human body are concentrated in the body of the fish.

When breeding a single farmed fish species, it is weak to respond to the variability of the consumption environment. Consumption may shrink due to a good harvest or socio-cultural influence of a single fish species, or damage may occur due to rapid price fluctuations. In addition, if death occurs despite the use of antibiotics and biocides to prevent death, it will have a great impact on farm household income. In festival farms, the biomass of algae increases as the concentration of nutrients increases due to the continuous feed administration and wastes of farmed fish species during fish and shrimp farming. High concentrations of algae have advantages such as water quality, stabilization of fish growth, and reduction of feed input. In addition, algae can absorb carbon dioxide, ammonia nitrogen, and nitrate nitrogen through photosynthesis. On the other hand, if it is excessive, it can lead to deterioration of water quality due to oxygen depletion at night without light. However, algae can be used as food for shellfish eating. It can be noted that it removes nutrient salts using algae generated in aquaculture and simultaneously enables them to be supplied as feed.

Since festival-style fish farms are difficult to secure water surface due to geographical conditions and are vulnerable to natural disasters such as typhoons and red tides, a high-density on-land farming method was developed that can produce a large amount of fish in a small area. Land farms can artificially control water temperature and can grow and produce throughout the year. However, like festival-type fish farms, land-based fish farms are devastating the surrounding sea because they rely on water exchange to manage water quality. In addition, in order to secure profitability compared to investment in land aquaculture farms, antibiotics, water quality improvers, and various chemicals are used while breeding fish at high density, which can accumulate in the body of aquaculture target species and cause harm to the human body.

Due to the above problems, two technologies have been developed and known to date.

First, it is a recirculating aquaculture system (RAS), which is an aquaculture method that maintains a stable water quality environment by applying various physicochemical water treatment processes at the rear of the farm for recirculation of aquaculture water. Recirculation filtration aquaculture systems can remove solids such as feed residues, red tides and wastes from aquaculture fish in aquaculture water by physicochemical methods (coagulation using polymer coagulants, sedimentation treatment, expensive filters, etc.) If not removed properly, ammonia nitrogen is generated. Ammonia nitrogen is very difficult to treat by physicochemical methods, and due to the biological toxicity of ammonia nitrogen, it may cause a decrease in the growth rate and death of farmed fish. In addition, the circulation filtration aquaculture system is difficult to operate due to the complexity of downstream equipment other than the aquaculture tank, and the extremely high equipment price, making it impossible to apply to small fish farms.

Second, Bio-floc technology activates heterotrophic microorganisms (microorganisms that synthesize bacterial proteins using organic carbon and ammonia as energy sources) to coexist with farmed fish and treats and purifies pollutants in farmed water. It is a farming method that does not require filtration processes such as water exchange and water treatment, as the microorganisms grown and proliferated again become protein food for farmed fish. However, in the aquaculture water treatment system applied with the current biofloat technology, the ammonia nitrogen treatment rate is very slow because organic matter and ammonia nitrogen are removed by microbial synthesis by heterotrophic microorganisms, and nitrite nitrogen is generated due to partial nitrification reaction. Occurs. Nitrite nitrogen exhibits higher biotoxicity than ammonia nitrogen, resulting in fish mortality. In addition, even with stable nitrification, accumulation of nitrate nitrogen is unavoidable when operating in a zero-emission cycle. Certain species can survive in spite of high nitrate nitrogen, but the scalability of the process is limited because high value-added species that are not adapted can not be applied.

Therefore, the present invention was proposed to supplement the problems of the prior art described above, improve water quality and reduce feed costs, and utilize an eco-friendly integrated circulating filtration system capable of complex farming of shrimp and cockles.

The present invention devised an eco-friendly integrated circulatory filtration system for shrimp and cockle complex aquaculture using salt-resistant aerobic granular sludge and microalgae to solve the problems of existing festival aquaculture, land aquaculture, biofloat technology and circulatory filtration aquaculture systems. .

The eco-friendly integrated circulatory filtration system for complex aquaculture as described above reduces the mortality rate of aquaculture fish, reduces the feed used in aquaculture by cultivating different species at the same time, and finally minimizes environmental pollution caused by discharged aquaculture water. .

In order to achieve the object of the above object, the present invention provides an aquaculture system in which aquaculture water is circulated and filtered, comprising: a shrimp aquaculture tank; A membrane separation tank that includes a salt-resistant aerobic granular sludge and a membrane module to simultaneously perform an oxidation reaction of organic matter and ammonia nitrogen and removal of suspended matters; A storage tank for controlling the flow rate flowing into a subsequent process; Microalgae culture tank for culturing microalgae; and Provides an eco-friendly circulating filtration aquaculture system configured to circulate the aquaculture water through the entire system including a cockle aquaculture tank.

As another embodiment of the present invention, there is provided an eco-friendly circulation filtration aquaculture system characterized in that the concentration of the salt-resistant aerobic granular sludge in the membrane separation tank is adjusted to 200 to 700 ppm.

As another embodiment of the present invention, it provides an eco-friendly circulation filtration aquaculture system, characterized in that the suspension concentration of the aquaculture water treated through the membrane separation tank is adjusted to 0.01 to 2.5 mg / L.

As another embodiment of the present invention, the concentration of microalgae in the microalgae culture tank is 700 to 950mg / m ³ It provides an eco-friendly circulation filtration aquaculture system, characterized in that adjusted.

As another embodiment of the invention, the volume of the shrimp aquaculture tank 100 is 30 to 60 m ³ It provides an eco-friendly circulation filtration aquaculture system, characterized in that it is adjusted.

As another embodiment of the present invention, there is provided an eco-friendly circulation filtration aquaculture system, characterized in that it further comprises a culture medium storage for promoting the growth rate of the microalgae.

As another embodiment of the present invention, it provides an eco-friendly circulation filtration aquaculture system, characterized in that it further comprises a UV sterilizer for inhibiting the growth of viruses and bacteria in the aquaculture water transferred from the cockle aquaculture tank to the shrimp aquaculture tank. .

An eco-friendly and efficient aquaculture system can be provided through the eco-friendly integrated circulation filtration system for shrimp and cockle complex culture using salt-resistant aerobic granular sludge and microalgae of the present invention.

1 is a system diagram of an eco-friendly circulation filtration aquaculture system of the present invention
Figure 2 is a graph showing the concentration of chlorophyll a in the microalgae cultivation tank in the eco-friendly circulating filtration aquaculture system of the present invention
Figure 3 is a graph showing the TN concentration before and after the filtration process through the system in the eco-friendly circulation filtration aquaculture system of the present invention
Figure 4 is a graph showing the COD concentration before and after the filtration process through the system in the eco-friendly circulation filtration aquaculture system of the present invention
Figure 5 is a graph showing the SS concentration before and after the filtration process through the system in the eco-friendly circulation filtration aquaculture system of the present invention

In order to fully understand the configuration and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be implemented in various forms and various changes may be applied. However, the description of the present embodiments is provided to complete the disclosure of the present invention, and to completely inform those skilled in the art of the scope of the invention to which the present invention belongs.

The present invention relates to a salt-resistant aerobic granular sludge and algae-based eco-friendly circulating filtration complex aquaculture system, which removes organic matter, ammonia nitrogen, nitrate nitrogen, etc. generated from fish farms through the aquaculture system to produce aquaculture water It is characterized in that it continuously circulates without exchanging, and provides algae as food to the aquaculture target species.

Specifically, the aquaculture system of the present invention includes a shrimp aquaculture tank 100, a membrane separation tank 200, a storage tank 300, a microalgae culture tank 400, and a cockle aquaculture tank ( 500) is configured to circulate the entire system.

More specifically, the culture water introduced into the shrimp aquaculture tank 100 of the present invention is transferred to the membrane separation tank 200 and purified, then transferred to the storage tank 300, and then to the microalgae culture tank 400 and cockle culture It is divided into the tank 500 and introduced. Thereafter, culture water containing a large amount of microalgae is additionally introduced into the cockle aquaculture tank 500 through the microalgae culture tank 400.

The amount of aquaculture water finally introduced into the cockle aquaculture tank 500 is adjusted equal to the amount of aquaculture water transferred to the storage tank 300, and then the aquaculture water flows back into the shrimp aquaculture tank 100, as described above. The same amount of aquaculture water circulates through the entire system and can grow shrimp and cockles.

For the above circulation, it is preferable that the flow rate of the cultured water transported through the entire system is maintained constant. it is desirable More specifically, the flow flux of the aquaculture water introduced into the shrimp aquaculture tank of the present invention is preferably adjusted to 30 to 50 m ³ /day, and it is preferable that the aquaculture water be transferred to other devices at a flow rate similar to the above.

In addition, it is preferable to adjust the flow rate of the aquaculture water to be introduced and discharged so that the flow rate of the aquaculture water circulating per day relative to the volume of the entire system device is 0.8 to 1.2 times.

If a large amount of aquaculture water is circulated faster than the above range, the water treatment time in the membrane separation tank in the present system cannot be sufficiently secured, and thus nitrogen and organic matter in the aquaculture water cannot be sufficiently removed.

On the other hand, if the aquaculture water is circulated too slowly and the circulation cycle becomes long, fresh aquaculture water cannot be continuously supplied into the shrimp aquaculture tank and cockle aquaculture tank, and contaminated aquaculture water accumulates for a long time, which can adversely affect shrimp and cockle culture. As such, the speed and flow rate of cultured water need to be properly adjusted within the above range.

On the other hand, since the system of the present invention continuously circulates the same amount of cultured water, separate discharge and inflow of cultured water is not required. However, in some cases, it may be necessary to supplement the evaporated farming water or discharge excessively contaminated farming water and surplus sludge, so a separate supplementary water inlet pump and discharged water and surplus sludge outlet may be included.

In FIG. 1 , discharged water and surplus sludge outlets 900 are located at the bottom of the membrane separation tank, but the location of the outlets does not necessarily have to be located at the bottom of the membrane separation tank, and may be installed at each bottom of each device if necessary.

Similarly, in FIG. 1 , make-up water is introduced into the membrane separation tank through the make-up water inlet pump 800, but the make-up water does not necessarily have to flow into the membrane separation tank, and can be introduced into each device as needed.

The amount of aquaculture water discharged as needed is preferably adjusted to 10% or less of the aquaculture water in the entire system, and the amount of supplemented aquaculture water is also preferably controlled to 10% or less of the aquaculture water in the entire system. If a large amount of aquaculture water is discharged or replenished than the above range, the concentration of oxygen and organic matter in the entire system may change rapidly, which may adversely affect the growth of aquaculture fish.

Looking at the configuration of each device constituting the system of the present invention in detail. First, a shrimp aquaculture tank 100 in which shrimp are nurtured may be installed.

Purified aquaculture water at a level suitable for the growth of shrimp may be introduced into the aquaculture tank.

Specifically, the concentration of organic matter in the inflowing aquaculture water is adjusted to 0.01 to 5 mg/L, more preferably 0.01 to 3 mg/L, and the concentration of ammonia nitrogen is adjusted to 0.01 to 8 mg/L, preferably 0.01 to 3 mg/L. It can be.

Preferred aquaculture water conditions as described above can be achieved through organic matter removal, denitrification, and floating matter removal processes through the membrane separation tank 200 and additional denitrification process of the microalgae culture tank 400.

On the other hand, the volume of the shrimp farming tank 100 is preferably adjusted to 30 to 60 m ³ . When the volume of the aquaculture tank is designed to be smaller than 30 m ³ , there is a disadvantage in that the amount of shrimp that can be reared at one time is too small. On the contrary, when the volume is designed to be larger than 60 m ³ , the sediment becomes stagnant as the reactor becomes too large. problems can arise. In addition, since the size of the membrane separation tank, which is a water treatment tank, should be increased according to the volume of the aquaculture tank, the overall system may become too large.

In addition, it is preferable that the water level of the shrimp aquaculture tank 100 be adjusted to 1 to 1.4 m, more preferably 1.2 to 1.4 m, in order to optimize shrimp farming.

As described above, the flow rate of the aquaculture water flowing into the shrimp aquaculture tank 100 or discharged from the shrimp aquaculture tank is preferably adjusted to circulate the entire system 3 to 5 times a day, and accordingly, the shrimp aquaculture tank ( 100), it is preferable to adjust the flow rate of aquaculture water introduced and discharged during the day to 1: 0.7 to 1: 1.3.

As described above, the flow rate of the aquaculture water discharged from the aquaculture tank is configured to be the same as the flow rate of the aquaculture water flowing into the membrane separation tank at the rear stage. When the aquaculture water is transferred faster than the above range, Since the water treatment time is not sufficiently secured, a problem may occur in that nitrogen and organic matter in the cultured water cannot be sufficiently removed.

Conversely, if the aquaculture water flowing into the aquaculture tank is transported too slowly, as the shrimp is cultured in the shrimp aquaculture tank 100, residual feed and waste products generated from the shrimp remain in the aquaculture water Bar, since fresh aquaculture water is not continuously supplied into the aquaculture tank, contaminated aquaculture water accumulates for a long time, which may adversely affect shrimp farming.

On the other hand, if the waste generated in the shrimp farming tank is not filtered and circulates through the entire system, it can inhibit the growth of cockles, which will be described later, and as this contaminated farming water flows back into the shrimp farming tank, the growth of shrimp also can greatly impede it.

Therefore, in order to remove the contaminants generated as above, the culture water of the shrimp aquaculture tank 100 is moved to the membrane separation tank 200 through the pump, and the organic matter and nitrogen removal reaction in the membrane separation tank and the suspended matter at the same time elimination reaction proceeds.

The flow rate entering and exiting the membrane separation tank 200 can be adjusted to be the same as the flow rate flowing into the shrimp aquaculture tank 100, and the volume of the membrane separation tank 200 is the volume of the shrimp aquaculture tank 100. It may be composed of 0.8 to 1.2 times the contrast.

If the size of the membrane separation tank 200 is too small, a problem arises in that it does not contain a sufficient amount of aerobic granular sludge, and accordingly, the purification efficiency of aquaculture water is reduced, which is not preferable. On the other hand, if the size of the membrane separation tank is larger than the above range, purification may not occur through aerobic granular sludge and aquaculture water may pass through the membrane separation tank as it is. Therefore, it is preferable to adjust the volume within the above range for optimization.

A specific purification reaction through the membrane separation tank occurs as follows.

* First, for purification, salt-resistant aerobic granular sludge may be contained in the membrane separation tank 200 of the present invention.

The salt-resistant aerobic granular sludge is granulated as the aerobic microorganisms contained in the activated sludge exhibit a self-fixation phenomenon and agglomerate with each other by biological, physical, and chemical factors without a biofilm such as an expensive carrier or a rotating body, Nitrosomonas ( Nitrosomonas, Nitrococcus, Halomonas, rhodohalobacter, Pararhodobacter, Marinospirillum, Trueper, Pelagibacterium ), and can be prepared using aerobic or facultative anaerobic microorganisms such as Halomonas, Nitrosomonas, Nitrococcus, Nitrococcus, and True to satisfy salt tolerance. It is preferable to include one or more microorganisms selected from the group consisting of Trueper, the Halomonas, Nitrosomonas, Nitrococcus, Nitrococcus, and Truepera ( It is more preferable to include most of Trueper).

In the case of the salt-tolerant aerobic granular sludge of the present invention, as described above, the salt-tolerance of the microorganisms was improved by selecting a group of salt-tolerant microorganisms and adjusting culture conditions. In addition, by appropriately adjusting the content range of the microorganisms, the salt resistance was increased, and at the same time, they were appropriately granulated so that contaminants could be efficiently treated.

The salt-resistant aerobic granular sludge proceeds with an oxidation reaction using dissolved oxygen as the final electron acceptor under aerobic conditions in the case of organic material oxidation and ammonia nitrogen oxidation reaction, and in the case of denitrification reaction, nitric acid as the final electron acceptor under anoxic conditions The denitrification reaction can be carried out using nitrogen.

In addition, as described above, in the case of the salt-tolerant aerobic granular sludge of the present invention, it is cultured to decompose feed debris and waste products discharged from fish farming in the salt concentration condition of seawater, and survives in a high-salinity environment to proceed with the filtration process.

Specifically, in the case of the salt-tolerant aerobic granular sludge of the present invention obtained through the above culture conditions, it can grow at a salinity of 10‰ to 40‰.

If the salinity that the salt-resistant aerobic granular sludge can withstand is less than 10‰, the salinity of the inflow water must be adjusted to less than 10‰. not. On the other hand, having culture conditions to survive even at a salinity exceeding 40 ‰ requires a very difficult process, which is not preferable from an economic point of view. Therefore, it is preferable to maintain the salt-resistant aerobic granular sludge at the above concentration in the aquaculture water, and it is more preferable to maintain it at 20 to 35‰ to optimize the aquaculture environment.

The average diameter of the salt-resistant aerobic granular sludge is preferably 0.1 to 0.5 mm. If the average diameter of the salt-resistant aerobic granular sludge is less than 0.1 mm, it is difficult to control the concentration of the salt-resistant aerobic granular sludge because sedimentation does not occur properly. On the other hand, when the average diameter exceeds 0.5 mm, the salt-tolerant aerobic granular sludge does not flow smoothly in the membrane separation tank and is precipitated at the bottom of the membrane separation tank, which is undesirable because organic matter and nitrogen treatment efficiency may decrease. In order to optimize the aquaculture environment, it is more preferable that the average diameter of the salt-resistant aerobic granular sludge exceeds 70% of the total particles of 0.2 to 0.4 mm.

Meanwhile, the amount of the salt-resistant aerobic granular sludge contained in the membrane separation tank 200 of the present invention is preferably adjusted to a concentration of 200 to 700 ppm.

If the concentration of the salt-resistant aerobic granular sludge is less than 200ppm, there is a problem that organic matter removal and nitrification do not occur, and conversely, if the concentration exceeds 700ppm, it may precipitate in the membrane separation tank and rather increase pollutants. .

In the present invention, a high concentration of aerobic microorganisms can be maintained by injecting the salt-tolerant aerobic granular sludge into the membrane separation tank 200 in an already granulated state, so that strong resistance to organic impact load can be maintained.

In addition, since the salt-resistant aerobic granular sludge of the present invention is composed of granular sludge having a certain size or more, floating sludge management is easy, and the salt-tolerant aerobic granular sludge concentration can be quickly adjusted because smooth solid-liquid separation is possible.

In addition, since the salt-resistant aerobic granular sludge is activated in a floating state in the membrane separation tank 200, the homogeneity is improved, so that remaining organic matter can be quickly removed and the efficiency of the nitrification and denitrification reactions can be increased.

The organic material oxidation reaction mechanism using the salt-resistant aerobic granular sludge occurs as shown in the following reaction formula.

C ₆ H ₁₄ O ₂ N + 3.358 O ₂ → 0.878 _C 5 H ₇ O ₂ N + 1.608 CO ₂ + 0.122NH ₄ ⁺ + 3.622H ₂ O + 0.122OH ^-

In addition, the complete nitrification reaction mechanism of ammonia nitrogen using the salt-resistant aerobic granular sludge occurs as shown in the following reaction formula.

22NH ₄ ⁺ + 37O ₂ + 4CO ₂ + HCO ₃ ^- → C ₅ H ₇ O ₂ N + 21NO ₃ ^- + 20H ₂ O+ 42H ⁺

Through the above reaction, the concentration of contaminants in the aquaculture water discharged from the membrane separation tank 200 can be adjusted below the biotoxic concentration. Specifically, the concentration of organic matter in the aquaculture water may be adjusted to 0.01 to 5 mg/L, more preferably 0.01 to 3 mg/L, and the concentration of ammonia nitrogen to 0.01 to 8 mg/L, preferably 0.01 to 3 mg/L. there is.

When the concentration of the organic matter exceeds 5 mg / L, eutrophication of the aquaculture water, red tide phenomenon, etc. may occur, and the contamination level increases, resulting in a rapid increase in the possibility of shrimp or cockle disease.

In addition, when the concentration of ammonia nitrogen exceeds 8 mg/L, eutrophication of aquaculture water, red tide phenomenon, etc. may occur, and the concentration of non-ionized ammonia (NH ₃ ) increases according to pH and water temperature. Due to the biotoxicity of ionized ammonia (NH ₃ ), the growth of shrimp or cockle is stunted and the mortality rate increases rapidly.

Therefore, it is preferable to optimize the growth of shrimp or cockle to control the concentration of organic matter and the concentration of ammonia nitrogen to 5 mg/L or 8 mg/L or less, respectively.

Meanwhile, in the membrane separation tank 200 of the present invention, physical purification through the membrane module 210 may be accompanied in addition to biological purification through the salt-resistant aerobic granular sludge.

The main purpose of the membrane module 210 is to reduce the concentration of suspended solids in cultured water.

Specifically, as the membrane module 210, a gravity filter, a vacuum filter, a pressure filter, a compression filter, or a centrifugal filter may be used. In addition, in the case of the membrane used in the membrane module, it is preferable to adjust the diameter of the hole to 0.1 to 10 μm in order to properly remove the suspended matter.

By filtering the suspended solids using the membrane module, it is possible to prevent the suspended solids from being transported to a subsequent process, and specifically, it is preferable to reduce the suspended solid concentration to 0.01 to 2.5 mg/L.

Aquaculture water purified through the membrane separation tank 200 of the present invention can be transferred to the microalgae culture tank 400 and the cockle culture tank 500 through the storage tank 300. At this time, the microalgae culture tank 400 If the concentration of suspended solids in the cultured water flowing into it is maintained higher than the above range, it may negatively affect the growth of microalgae.

Specifically, organic matter and bacteria are mixed in the suspended matter, and the floating organic matter scatters light necessary for photosynthesis as above, thereby inhibiting photosynthesis of microalgae. In addition, microalgae and bacteria are heterogeneous substances in a competitive relationship with each other, and in the case of bacteria, substances that inhibit the growth and survival of microalgae are discharged.

Therefore, it is necessary to remove these suspended matters for the growth of microalgae.

In addition, sand for cockle farming is located at the bottom of the cockle aquaculture tank 500, and when the concentration of suspended matter in the farming water is high, floating matter accumulates in the sand and rotting may occur.

Therefore, it is preferable to reduce the concentration of suspended matter in the aquaculture water discharged through the membrane separation tank 200 to 0.01 to 2 mg/L through the above-mentioned salt-resistant aerobic granular sludge and the suspended matter reduction action through the membrane module.

* Aquaculture water discharged after the purification in the membrane separation tank 200 may be stored in the storage tank 300. The volume of the storage tank is preferably formed to be 0.8 to 1.2 times that of the shrimp farming tank.

The storage tank 300 serves to distribute an appropriate level of flow rate to the microalgae culture tank 400 and cockle aquaculture tank 500.

Specifically, in the case of the shrimp aquaculture tank 100, the membrane separation tank 200, the reservoir tank 300, and the cockle aquaculture tank 500, the aquaculture water is circulated throughout the day, but it takes a long time to cultivate microalgae. In order to supply sufficiently grown microalgae to the cockle aquaculture tank, it is preferable that the culture water is transported through the microalgae culture tank 400 intermittently, and the inflow of such culture water can be controlled through the storage tank.

On the other hand, more specific functions of the microalgae culture tank 400 and cockle farming tank 500 receiving culture water from the reservoir tank 400 as described above are as follows.

The microalgae culture tank 400 is a place where microalgae provided as food for cockles are cultured, and the microalgae in the microalgae culture tank are not yet removed in the membrane separation tank 200. Residual nitrogen, carbon dioxide and trace elements can absorb and grow through photosynthesis.

On the other hand, since excess residual nitrogen is removed in the microalgae culture tank 400, the aquaculture system of the present invention is nitrogen more suitable for the growth of cockles and shrimp than simply using only the membrane separation tank 200. It has the advantage of being able to adjust the concentration.

A separate culture medium reservoir 450 may be additionally provided on the aquaculture system of the present invention to promote the growth of the microalgae.

Microelements capable of promoting the growth of algae are stored in the culture medium storage in the form of a culture medium, and the culture medium can be supplied to the microalgae culture tank 400 intermittently.

Trace elements constituting the culture solution may include ZnSO ₄ 7H ₂ O, CoCl ₂ 6H ₂ O, (NH ₄ ) ₆ Mo ₇ O ₂₄ 4H ₂ O, CuSO ₄ 5H ₂ O, etc., and additional vitamins. may contain this.

On the other hand, the concentration of microalgae in the microalgae culture tank 400 through the supply of the culture medium is preferably adjusted to 700 to 950mg/m ³ .

When the concentration of microalgae is lower than the above range, a large amount of aquaculture water is required to provide the same amount of food to the cockle, so the problem is that the amount of culture water containing microalgae flowing into the cockle reaction tank is excessively increased. may occur, which is not desirable. Therefore, in order to provide sufficient microalgae with a small amount of aquaculture water, it is preferable to maintain a high concentration of microalgae, but an excessive concentration of microalgae may limit the growth of each microalgae during photosynthesis, and the above range It is desirable to adjust within.

Specifically, in order to maintain the microalgae concentration as above, the volume of the microalgae culture tank 400 is V _m , and the flow rate of the culture solution transferred from the culture medium storage 450 to the microalgae culture tank 400 for one day is Q _d , Q _{d :} V _m is preferably adjusted to 1: 15 to 1: 35.

When the flow rate including microalgae is adjusted to an appropriate range as described above, as shown in FIG. 2, chlorophyll a representing the concentration of microalgae in the aquaculture water introduced into the microalgae culture tank 400 and discharged through the microalgae culture process After the concentration of the initial adjustment period, 700 to 950mg / m ³ It can be seen that it is constantly adjusted.

On the other hand, in the case of cultured water containing microalgae in the microalgae culture tank 400, it is preferable to transfer it to the cockle aquaculture tank once a day for 1 to 2 hours. Since the growth rate of algae is rather slow, it is preferable to adopt the above intermittent supply method in order to provide the algae to a cockle aquaculture tank after growing the algae to a certain level or higher.

More specifically, the volume of cultured water introduced and discharged through the microalgae culture tank for a day: The volume of the microalgae culture tank is preferably adjusted so that the volume of cultured water is maintained within the range of 1: 10 to 1: 30. . If the culture water is transported slower than this, it is difficult to supply a sufficient amount of microalgae to the cockles, and conversely, if the culture water is transported too quickly, microalgae that have not grown sufficiently are supplied and the desired efficiency cannot be obtained.

The required amount of aquaculture water flowing from the microalgae culture tank to the cockle aquaculture tank may vary depending on the amount of cockle inoculation in the cockle aquaculture tank. On the other hand, in the present invention, 50 to 70 cockles are inoculated per 1 m ² area to optimize cockle farming, and accordingly, 2 to 3 m ³ /day of aquaculture water containing microalgae is supplied to the cockle aquaculture tank. (500) and the amount of microalgae on the shrimp aquaculture tank (100) can be optimized.

The reason why the amount of aquaculture water containing the microalgae should be adjusted within the above range is as follows.

First, as described above, the concentration of microalgae in the microalgae culture tank 400 is adjusted to 700 to 950mg/m ³ , so that the aquaculture water containing microalgae will flow into the cockle aquaculture tank 500 at the same rate as above. In this case, it is possible to provide a concentration of microalgae optimized for the growth of cockles. At this time, the residual algae that are not consumed by the cockles are introduced into the shrimp aquaculture tank 100. Microalgae below a certain level can promote the growth of shrimp in the infancy stage, but high concentrations of microalgae are toxic. This can negatively affect the shrimp's respiration.

That is, when a larger amount of cultured water than the above range is introduced, the amount of residual algae that the cockles have not consumed increases excessively, resulting in a high concentration of microalgae that can inhibit the growth of shrimp, which is not preferable.

On the contrary, when an amount of culture water less than the above range is introduced, there is a disadvantage in that sufficient microalgae for cockle culture cannot be supplied.

In order to grow cockles by receiving aquaculture water containing a large amount of microalgae from the microalgae culture tank as above, the volume of the cockle aquaculture tank 500 can be adjusted to 10 to 20 m ³ , and the water level of the cockle aquaculture tank is 0.3 It is preferably adjusted to 0.6 m.

When the water level of the cockle aquaculture tank is maintained lower than 0.3 m, the cockle exposed to the outside of the culture water is directly exposed to the atmosphere, which may adversely affect growth. On the other hand, as the water level increases, the amount of water to be treated increases. However, when breeding fish and shellfish, a relatively high water level is not required. can

On the other hand, the concentration of organic matter in the aquaculture water in the cockle aquaculture tank 500 through the above circulation process is 0.01 to 5 mg/L, more preferably 0.01 to 3 mg/L, the concentration of ammonia nitrogen is 0.01 to 8 mg/L, and more Preferably, it can be adjusted to 0.01 to 3 mg / L, and the culture water can be transferred to the shrimp aquaculture tank 100 again to circulate the culture water.

In the microalgae culture tank 400 and cockle aquaculture tank 500, organic matter and nitric acid are hardly generated. Therefore, if only the concentration of microalgae is adjusted, the culture water transferred from the cockle aquaculture tank 500 to the shrimp aquaculture tank 100 can be maintained in an optimal aquaculture state adjusted in the membrane separation tank.

However, since some viruses and bacteria may be generated during the microalgae culturing process or cockle aquaculture tank, a separate UV sterilizer 600 may be installed to remove them.

On the other hand, the system of the present invention may include an oxygen generator 700, and the oxygen generator is connected to the shrimp farming tank 100 and the cockle farming tank 500 to adjust the amount of oxygen suitable for the growth of shrimp and cockles.

Specifically, the amount of dissolved oxygen suitable for the growth of shrimp and cockles may be adjusted to 5 to 20 mg/L.

As described above, in the case of the circulation filtration aquaculture system of the present invention, by operating the shrimp aquaculture tank and the cockle aquaculture tank at the same time, economically superior effects can be obtained, and through the operation of the membrane separation tank equipped with aerobic granular sludge and membrane modules, shrimp and cockle It can provide aquaculture conditions optimized for the growth of

In particular, the salt-resistant aerobic granular sludge and algae-based eco-friendly circulation filtration complex aquaculture system of the present invention does not use chemicals used in the chemical treatment process because the aquaculture water treatment process is performed biologically. In addition, mass mortality due to external environment (water temperature, disease, natural disaster, etc.) can be prevented through the non-discharge circulation of aquaculture water. In addition, it is possible to set up a sales strategy that can prepare for the changing consumption environment with complex forms.

In addition, in the microalgae culture ancestor for cockle culture, biomass increases by absorbing nitrogen and carbon dioxide through photosynthesis of algae, and it can be supplied as food for cockles. That is, through the operation of the microalgae culture tank, it is possible to treat residual nitrogen that is not treated in the membrane separation tank, so that it is environmentally friendly and can reduce the amount of feed, thereby providing an aquaculture system with excellent overall efficiency.

Hereinafter, specific examples are presented to aid understanding of the present invention. However, the following examples are only provided to more easily understand the present invention, and the content of the present invention is not limited by the examples.

[Example 1]

Shrimp aquaculture tank according to the present invention, aquaculture water treatment device inoculated with salt-resistant aerobic granular sludge and equipped with a membrane separation tank, distributing water to microalgae culture tank and cockle aquaculture tank, retention tank for flow control, and remaining in aquaculture water by photosynthesis of microalgae Including a microalgae culture tank that absorbs nitrogen and proliferates the growing biomass as feed for cockles, a culture medium storage tank for storing a culture medium that promotes the growth rate of microalgae, and a cockle culture tank for cockle farming, Farming water was transferred from the tank to the shrimp farming tank, and the system was driven so that the farming water continuously circulated through the entire process equipment.

Yeosu seawater was added as the first inflow water, and then the evaporated water was supplemented. The volume of the shrimp farming tank was 39.6 m ³ , and the flow rate of the inflow water was adjusted to 39.6 m ³ /day.

The volume of the membrane separation tank was adjusted to 39.6 m ³ , and the aerobic granular sludge injected into the membrane separation tank was injected so that the mixed solution suspended solids (MLSS) concentration was about 700 mg/L. In the case of operating conditions, hydraulic retention of the sewage treatment device manufactured as described above with inflow agitation (10 minutes), aeration (120 minutes), anoxia (80 minutes), sedimentation (10 minutes), outflow and rest (20 minutes) The operation time was 8 hours, and the flow rate of the inflowing cultured water was injected at 39.6 m ³ /day. During aeration, air was injected at a flow rate of 1 L/min through a diffuser attached to the bottom of the apparatus using a blower. In addition, a membrane module was installed in the membrane separation tank.

The volume of the microalgae culture tank was adjusted to 39.6 m ³ , and the flow rate of the inflowing culture water was adjusted to 2.27 m ³ /day.

The volume of the cockle aquaculture tank was adjusted to 14.2 m ³ , and the flow rate of the inflowing culture water was adjusted to 39.6 m ³ /day.

The survival rate and growth rate of shrimp and cockles according to the operation of the system of the present invention were measured. Cockle growth rate (Specific growth rate, SGR) was calculated through Equation (1) below, and Cockle survival rate (SR) was calculated through Equation (2) below.

Equation (1): SGR = {ln(A ₂ /A ₁ )/(T ₂ -T ₁ )} × 100

(Where A2 is the weight at the end of the experiment (g), A1 is the weight at the start of the experiment (g), T2 is the date at the end of the experiment (day), and T1 is the date at the start of the experiment (d).)

Equation (2): SR = (N ₂ /N ₁ ) × 100

(Where N2 is the number of individuals at the end of the experiment (US), and N1 is the number of individuals at the start of the experiment (US).)

In addition, in the case of the present invention, since there is no aquaculture water discharged to the outside because it is operated as a non-discharge aquaculture tank, in order to measure the aquaculture water treatment efficiency, the aquaculture water (emission water) released from the shrimp aquaculture tank is compared to shrimp farming again. The pollutant removal efficiency was observed by comparing the aquaculture water (treated water) flowing into the tank.

Cockle survival rates and growth rates through the above examples are shown in Table 1 below.

Date
(day) Early 30 60 90 120 150 180 210 Average weight (g) 12.49 13.88 14.70 16.96 18.82 19.04 19.11 19.23 standard deviation (g) 0.41 0.30 0.38 0.14 0.84 0.47 0.49 0.38 survival rate (%) 97.3 96.0 94.7 94.0 92.0 91.4 91.0 90.0 Average leg length (cm) 31 33 34 34 36 36 37 37 Average height (cm) 28 28 29 29 31 31 31 32 Average leg width (cm) 22 22 24 24 23 23 24 24

The total SGR of the cockle was 0.205%, and the SR was 93.3%, which was very good. On the other hand, the shrimp survival rate and growth rate through the above examples are shown in Table 2 below.

Date
(day) Early 15 45 75 105 120 135 160 180 210 Average weight (g) 0.006 0.021 0.114 3.184 10.119 12.240 18.627 22.714 29.561 33.842 standard deviation (g) 0.001 0.003 0.014 0.478 1.619 1.469 2.049 1.235 2.144 2.318 survival rate
(%) - 99.0 ± 5.91 98.1 ± 4.53 97.2 ± 5.87 96.3 ± 7.32 95.4 ± 6.53 94.6 ± 6.17 93.7 ± 8.97 92.7 ± 5.40 ±92.0
3.50

The total SGR of the shrimp was 4.11%, and the SR was 92.0 ± 3.50%, which was very good.

The aquaculture water treatment efficiency using the aquaculture system of the embodiment can be grasped through FIGS. 3 to 5.

Specifically, FIG. 3 shows the denitrification efficiency of the system of the present invention. As shown in Figure 3, the TN concentration representing the nitrogen nitrate concentration of the aquaculture water discharged from the shrimp farming tank of the present invention is measured at 10 to 45 mg / L, and it can be confirmed that the average nitrogen nitrate concentration is 34 mg / L can On the other hand, as the denitrification reaction proceeds through the membrane separation tank and the microalgae culture tank of the present invention, the nitrogen oxide concentration of the aquaculture water flowing into the shrimp farming tank is reduced to 0.01 to 8 mg/L, and is reduced to 2.67 mg/L on average. can confirm that it is.

The denitrification efficiency of the entire system as above was 70 to 99% during the system operation period, and the average denitrification efficiency was about 91%.

4 shows the organic matter removal efficiency of the membrane separation tank. As shown in Figure 4, the COD concentration representing the concentration of organic matter in the aquaculture water discharged from the shrimp farming tank of the present invention is measured at 7 to 35 mg / L, and it can be confirmed that the average COD concentration is 17.5 mg / L. there is. On the other hand, as the organic matter removal reaction proceeds through the membrane separation tank of the present invention, the COD concentration of the aquaculture water flowing into the shrimp farming tank is reduced to 0.01 to 5 mg/L, and it can be confirmed that it is reduced to 1.96 mg/L on average. .

The organic matter removal efficiency of the entire system as described above was 77 to 99.5% during the system operation period, and the organic matter removal efficiency was about 88% on average.

5 shows the efficiency of removing suspended matter in a membrane separation tank. As shown in Figure 5, the SS concentration representing the concentration of suspended matter in the aquaculture water discharged from the shrimp farming tank of the present invention is measured at 10 to 15 mg / L, and it can be confirmed that the concentration of suspended matter of 12.5 mg / L appears on average. there is. On the other hand, it can be confirmed that the suspension removal reaction proceeds through the membrane separation tank of the present invention, and the concentration of suspended matters in the aquaculture water flowing into the shrimp farming tank is reduced from 0.01 to 2.5 mg/L, and is reduced to 1.15 mg/L on average. there is.

The organic matter removal efficiency of the entire system as described above was 80 to 99.5% during the system operation period, and showed an average denitrification efficiency of about 90.8%.

The results of organizing the data of FIGS. 3 to 5 are as shown in Table 3 below.

division TN ^* TCOD _Cr T-SS Concentration in effluent (mg/L) 34.0 17.5 12.5 Concentration in treated water (mg/L) 2.67 1.96 1.15 Treatment efficiency (%) 91.0 88.0 90.8

*, This is the result after 65 days when the treatment efficiency was stabilized.

As can be seen from the above examples, when using the circulation filtration aquaculture system of the present invention, by not discharging seawater once introduced during the aquaculture period, it is possible to reduce environmental pollution compared to general festival aquaculture farms.

In particular, in the case of the present invention, purification is performed using a membrane separation tank including aerobic granular sludge and a membrane module, and additionally, nitrate nitrogen concentration generated from shrimp farming in a microalgae culture tank used for cockle growth By proceeding with a process to reduce the organic matter concentration is 0.01 to 5mg / L, the concentration of ammonia nitrogen is 0.01 to 8mg / L, the concentration of suspended matter is adjusted to 0.01 to 2mg / L, aquaculture optimized for the growth of shrimp and cockles A number of conditions can be provided.

In addition, in the present invention, by breeding shrimp and cockle at the same time, it is possible to reduce the amount of feed required and accompanying equipment, thereby obtaining economically advantageous effects.

10: circulation filtration aquaculture system
100: shrimp farming tank
200: membrane separation tank 210: membrane module
300: reservoir
400: microalgae culture tank 450: culture medium reservoir
500: cockle farming tank
600: UV sterilizer
700: oxygen generator
800: makeup water inlet pump
900: discharge water and surplus sludge outlet

Claims (7)

In the aquaculture system in which aquaculture water is circulated and filtered,
shrimp farming;
A membrane separation tank that includes a salt-resistant aerobic granular sludge and a membrane module to simultaneously perform an oxidation reaction of organic matter and ammonia nitrogen and removal of suspended matters;
A storage tank for controlling the flow rate flowing into a subsequent process;
Microalgae culture tank for culturing microalgae; and
An eco-friendly circulating filtration aquaculture system configured to circulate the aquaculture water through the entire system including a cockle aquaculture tank.
According to claim 1,
Eco-friendly circulation filtration aquaculture system, characterized in that the concentration of the salt-resistant aerobic granular sludge in the membrane separation tank is adjusted to 200 to 700 ppm.
According to claim 1,
Eco-friendly circulation filtration aquaculture system, characterized in that the suspension concentration of aquaculture water treated through the membrane separation tank is adjusted to 0.01 to 2.5 mg / L. According to claim 1,
Eco-friendly circulation filtration aquaculture system, characterized in that the microalgae concentration in the microalgae culture tank is adjusted to 700 to 950mg / m ³ .
According to claim 1,
Eco-friendly circulation filtration aquaculture system, characterized in that the volume of the shrimp aquaculture tank is adjusted to 30 to 60 m ³ .
According to claim 1,
Eco-friendly circulation filtration aquaculture system, characterized in that it further comprises a culture medium storage for promoting the growth rate of the microalgae.
According to claim 1,
Eco-friendly circulation filtration aquaculture system, characterized in that it further comprises a UV sterilizer for inhibiting the growth of viruses and bacteria in the aquaculture water transferred from the cockle aquaculture tank to the shrimp aquaculture tank.

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