JP2001231394A - Method for culturing capitella sp.1 for cleaning organic substance sludge and method for cleaning organic substance sludge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for more efficiently cleaning an organic substance sludge by preculturing a large amount of Capitella sp.1 as benthos and positively scattering the cultured Capitella sp.1 on the organic substance sludge in the autumn when this organism can live. SOLUTION: The method for culturing Capittela sp.1 for cleaning an organic substance sludge is characterized in that a feed is periodically scattered on a Capitella sp.1 culture substrate and Capitella sp.1 stored in a seawater tank, and Capitella sp.1 is cultured at 5-25 deg.C with aeration until Capitella sp.1 density reaches 4×106 organisms/m2. The method for cleaning an organic substance sludge is characterized in that the culture substrate containing Capitella sp.1 in high density obtained by the culturing method is scattered on a deposited sludge in a target sea area to be cleaned and the organic substance sludge is cleaned by utilizing the organic substance consumption force of Capitella sp.1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for cultivating Itokai for purifying organic sludge and a method for purifying organic sludge. More specifically, the high-density density of the cod that is used to efficiently purify large amounts of organic sludge deposited on the seabed due to food residues and fish excreta (feces) sprayed at fish farms The present invention relates to a culture method and a method for purifying organic sludge using a strawberry grown by the method.

[0002]

2. Description of the Related Art While aquaculture and fishery, mainly hamachi and thailand, are widespread in coastal areas around Japan, only 10 to 20% of bait scattered in fish farms contributes to the growth of cultured fish. (“Remaining Sea Culture and Self-Pollution” (edited by the Japanese Fisheries Society), 42-51 (1977),
Koseisha Koseikaku). 80-90 of organic matter sprinkled in fish farm
% Becomes dissolved or suspended matter, or becomes a nutrient due to the metabolic activity of fish, flows out to the sea area around the fishery, and deposits on the sea floor as feces and residue. A large amount of organic matter deposited on the sea floor generates harmful hydrogen sulfide during the high water temperature period (summer) due to an anaerobic decomposition process, and the sea floor is contaminated with a large amount of organic sludge (sludge) that cannot inhabit living things. How to remove this organic sludge is a major problem for the maintenance and development of aquaculture.

As a countermeasure for removing organic matter sludge, a method of promoting the exchange of seawater and promoting the decomposition of organic matter on the seafloor by dredging, covering with sand, charging lime, and excavating a bay mouth so far has been carried out. Etc. have been proposed. However, these methods change the terrain and characteristics of the sea area, and thus the entire environment, and their effects on the entire ecosystem are not clear. Further, these methods are enormous and are not realistic measures. On the other hand, in the fall when the seawater temperature falls, oxygen is supplied to the sludge on the seabed by the convection phenomenon.
It is purified by the action of bentos (benthic organisms), which use as a nutrient source.

[0004]

Means for Solving the Problems The present inventors have previously cultured a large amount of benthos (benthic organism), and then actively scattered this on organic sludge in the autumn when the organism can inhabit. We considered that organic sludge could be purified efficiently. As benthos (benthic organisms), spioceae and small polychaetes are known.
It is known that pitella sp.1) appears at high density in areas contaminated with organic matter and proliferates explosively during the recovery period of sludge environmental conditions (J. Mar. Res., 32, 253-184 (1974)). Accordingly, the present inventors have conducted intensive studies on the mass cultivation of Itokai and completed the present invention.

That is, the present invention provides the following method for cultivating a coconut oyster for purifying organic sludge and a method for purifying organic sludge. 1) It is characterized in that bait is regularly sprayed on the cultivation substrate and locust moss contained in the seawater tank, and cultivation is performed at a density of 4 × 10 ⁶ individuals / m ² or more while aerating at a temperature of 5 to 25 ° C. Cultivation method of strawberry cultivation for purification of organic sludge. 2) The method of cultivating organic sludge purifying strawberry as described in 1 above, wherein a plastic container containing a strawberry cultivation substrate and strawberry is placed on the bottom of a seawater tank for culturing. 3) The feed is 1.0 gC / m ² · day to 2.8 in terms of organic carbon content.
^{2. The} method for cultivating a cocoon for purifying organic sludge as described in 1 above, wherein the cultivation is carried out in an amount of gC / m ² · day. 4) The method for cultivating a cocoon for purifying organic sludge as described in 1 above, wherein the cultivation is performed while maintaining the ammonia concentration in the seawater tank at 1.2 mM or less. 5) The method for cultivating a strawberry for purification of organic sludge as described in 2 above, wherein the strawberry cultivation substrate and the strawberry are stored on a plastic sheet spread on the inner surface of a plastic container and cultured. 6) The method for cultivating Itokai for purifying organic sludge as described in 1 or 2 above, wherein the culture substrate is fine sand. 7) The organic sludge purifying organic sludge as described in 2 or 5 above, wherein a plastic container or a plastic container and a plastic sheet having a strength enough to withstand the operation of dispersing cultured strawberry in an organic sludge seawater area is used. Culture method. 8) Spreading a culture substrate containing the nested locusts obtained by the method according to any one of the above 1 to 7 at a high density on sedimentary sludge in a seawater area to be purified, and utilizing the organic matter consumption power of nested nests A method for purifying organic sludge, comprising purifying odor.

Hereinafter, the present invention will be described in detail. (1) Itokai Ito belongs to small polychaetes (annelids) and is a thread-like organism with an adult body length of about 10 mm and a maximum diameter of about 1 mm. In summer, when the seafloor environment is significantly anaerobic, the growth rate is extremely slowed down, but the seafloor environment recovers from autumn to winter, when the water temperature is 10 to 15 ° C, and the dissolved oxygen in the bottom water becomes saturated or close to it, It shows an explosive proliferative ability by repeating adult growth and reproduction in about 4 to 6 weeks. During the growth process, the sludge is decomposed and removed because the organic matter in the organic sludge is used as a nutrient source.

[0007] In the present invention, a large amount of strawberry cultivated in advance from autumn to winter when the seafloor environment recovers is sprayed on organic sludge, so that a high-density population that cannot occur by natural phenomena can be obtained for a short period of time. To efficiently purify organic sludge deposited on the sea floor. In the present invention, in order to efficiently purify organic sludge deposited on the seabed of a fish farm (aquaculture fish), a strawberry oyster is grown at a density of 4 × in a culture substrate.
The cells are cultivated to 10 ⁶ individuals / m ² or more, preferably 5 × 10 ⁶ individuals / m ² or more, and are spread.

[0008] In the present specification, the cultivation density of the locust is shown per unit area, but this does not mean simply the number of locusts present only on the surface, but is used to measure the cultivation density. This means a value obtained by subtracting the total number of nests (the nests that live only at a depth of about 2 cm from the surface) in the sample by the area of the sampling core.

(2) Cultivation Method of the Strawberry In the present invention, the bait is regularly sprayed on the Strawberry culture substrate and the Strawberry that are accommodated in the seawater tank to culture the Strawberry. In this culture, in consideration of the workability when spraying a cultivated strawberry in a sea area to be purified in a large amount at a predetermined density or more, a container made of plastic or the like having a size that is easy for an operator to handle is placed, It is preferably carried out in that container. The feed may be any easily decomposable organic substance. For example, a mixed feed for fish, a moist pellet, or the like can be used. This is scattered from the upper part of the seawater tank at a predetermined amount regularly (usually once a day) for feeding.

The culture temperature is 5 to 25 ° C., preferably 10 to 25 ° C.
It is preferable that the temperature is set to 20 ° C., and that aeration is appropriately performed by an air pump during the culture to keep the dissolved oxygen concentration in the seawater in a saturated state. Strawberries used for culture may be larvae or adults. The larvae and adult larvae collected from nature are used. In the case of larvae, the collected incubating females are selected and left for one to several individuals in a beaker filled with seawater for several days, and then the floating larvae are collected and used.

[0011] The culture substrate is not particularly limited as long as it is suitable for cultivation of Itokai, but fine sand (fine sand) is preferably used. When fine sand is used, nesting creatures proliferate while sunk into the gaps, and have the advantage that they are less likely to be eaten by fish living on the seabed immediately after being scattered. As fine sand, the particle size is 150 μm or less, and the median particle size is 50 ~
It is preferably about 80 μm. As such fine sand, generally available ones can be used.

As the culture vessel, a plastic (for example, one made of polyolefin such as polyethylene, polypropylene, polyvinyl chloride, etc.) is used which is strong enough to withstand the operation of spraying the organic sludge in the seawater and is large enough for the operation. It is preferable to use a biodegradable plastic container that is decomposed by the action of microorganisms even when left in seawater after the spraying operation. As a container, one side is 10 to 30 cm,
A rectangular box-shaped container having a depth of about 5 to 10 cm is suitable.

When a culture substrate is directly put into a culture container for culturing, the pressure of seawater received during the culture causes the culture substrate to stick to the container, which hinders the spraying operation. Therefore, it is preferable to spread a plastic sheet on the inner surface of the container and culture on the sheet. In this case, it is possible to collect the culture substrate containing the locust oysters at a high density from the container for each sheet without damaging the strawberry during the culturing, and to perform the spreading operation. As the material of the plastic sheet, the same material as described above for the container is used. The cultivation is continued until the density of the strawberry grows to a predetermined high density (4 × 10 ⁶ individuals / m ² or more). Whether or not the cells have grown to a predetermined density is determined by sampling over time and measuring the number of locusts under a stereoscopic microscope.

(I) Amount of Food Spread When the organic carbon content in the culture substrate increases, the cultivation environment of the straggler deteriorates. That is, if the organic carbon content in the culture substrate exceeds 2.8 gC / m ² , it will adversely affect the growth of strawberry. Therefore, it is good to sprinkle bait (easy decomposable organic matter) in such an amount that the organic carbon content in the culture substrate is 2.8 gC / m ² or less, preferably about 2.5 gC / m ² or less. The sprayed amount, 1.0~2.8gC / m ² in an organic carbon content in terms of the culture substrate, preferably 1.5~2.5gC / m ^2,
More preferably 1.8~2.2gC / m ² approximately.

(Ii) Ammonia concentration in the culture seawater Contamination of the seawater for cultivation of the mosquitoes adversely affects the growth of mosquitoes. Seawater contamination can be determined by using the ammonia concentration generated as a result of the decomposition of organic matter as an index. The ammonia concentration that does not affect the growth of the strawberry is 1.2 mmol / L (1.2 mM) or less. In order to maintain the ammonia concentration in seawater at a level suitable for cultivation of nests, it is conceivable to exchange some of the seawater in the sea tank at regular intervals. There is a risk that the larvae will be thrown away by exchanging seawater. Therefore, it is preferable that seawater is not changed as much as possible.

As a method for maintaining the ammonia concentration at a predetermined level without frequently exchanging seawater, there is a method for maintaining the ammonia concentration at 1.2 mM or less until the nests grow high density. It is preferable to use a large amount of seawater. By doing so, it is not necessary to change the seawater, workability is improved, and it is possible to prevent the loss of Itokai,
It is possible to efficiently cultivate a strawberry.

[0017]

EXAMPLES The present invention will be described in more detail with reference to Test Examples and Examples, but the present invention is not limited to the following Examples.

Test Example 1: Influence of Feeding Amount on Strawberry Growing Fine Sand as Culture Substrate (K-Kumamoto Silica Sand Co., Ltd., K-
(8, median particle diameter: 60 μm) 900 g and 2 liters of seawater were stored in four plastic containers made of polyvinyl chloride (30 × 20 × 10 cm, manufactured by Chopura Kogyo Co., Ltd.) 500 individuals were placed.
Put these culture vessels in a constant temperature seawater tank set at 18.0 ° C,
It was ventilated with an air pump (3.0 cm in diameter). As bait,
Powdered moist pellets for Hamachi cultivation (manufactured by Mercian Co .; organic carbon content: 44%) were added once a day. The amount of feed was increased in accordance with the growth of the pods and the growth of the whole colony. The following three test plots L, M, and H with different feeding amounts were provided, and the population density of the mosquitoes 6 weeks after the start of the culture was measured, and the average value was obtained.

Feeding amount: Test group L: 0.1 g for the first week, 0.2 g for the second to eighth weeks, test group M: 0.1 g for the first week, 0.2 g for the second week, third to 0.3 g at the 8th week, test plot H: 0.1 g at the first week, 0.2 g at the second week, 0.3 g at the 3rd and 4th weeks, 0.4 g at the 5th to 6th weeks.

The population density of Itokai was measured by collecting a culture substrate, fixing it with a 10% formalin solution in which rose bengal was dissolved, and sieving through a 125 μm mesh sieve to measure under a stereoscopic microscope. The organic carbon content converted per unit area of the culture substrate was determined by the following formula.

## EQU1 ## Organic carbon content (gC / m ² ) = feed amount (g) × 1
0000 (cm ² ) / 600 (cm ² ) × 0.44 The results are shown in Table 1.

[0021]

[Table 1] Table 1 Test plot Strawberry population density Organic carbon content (number of individuals / 10 cm ² ) (gC / m ² ) L 3079 1.5 M 3989 2.2 H 442 2.9

From Table 1, it can be seen that, in the test plot H containing a high concentration of organic carbon, the density of the codling population is very low, and when the organic carbon content is 2.9 gC / m ² or more, the growth of codling is inhibited. Was. In the test plot L and the test plot M, a high density of the cod population was obtained, and the preferable amount of bait for the growth of the cod was not more than 2.8 gC / m ² , especially about 2.2 gC / m ^{2 in} terms of organic carbon content. Is preferable.

Test Example 2: Effect of Ammonia Concentration in Sea Water on Growth of Strawberry Inspection 900 g of the same culture substrate as in Test Example 1 and 2 liters of sea water were used in the same four plastic containers (30) as used in Test Example 1. × 20 × 10 cm), and 500 larvae of each larva were placed. The culture vessel was placed in a thermostat set at 18.0 ° C. and ventilated with an air pump (3.0 cm in diameter). As a bait, the same moist pellet powder for hamachi cultivation as in Test Example 1 was added once a day. The amount of feed was increased in accordance with the growth of the individual colonies and the growth of the whole colony, and 0.1 g in the first week, 0.2 g in the second week, and 0.1 g in the third to eighth weeks.
3 g. Culture was performed for 8 weeks, during which time the frequency of seawater exchange was changed three times a week (test zone A), twice a week (test zone B), once a week (test zone C), and once every two weeks (test zone D). ) Were provided, and after 4 weeks, 6 weeks, and 8 weeks from the start of the culture, the density of the cod colony and the ammonia concentration in seawater were determined in the same manner as in Test Example 1. It measured and the average value was calculated | required. Ammonia concentration was measured using 0.25 liters of seawater at the time of seawater exchange.
Suction filtration was performed with a pump using an F / F glass fiber filter, and the ammonia concentration of the obtained filtrate was measured using an automatic nutrient concentration measurement device (Technicon II).
The results are shown in Table 2 (colony density) and Table 3 (ammonia concentration).

[0024]

[Table 2] Table 2 Culture period (weeks) Colony density (number of individuals / m ² ) Test plot A Test plot B Test plot C Test plot D 0 7,962 7,962 7,962 7,962 4 7,317 × 10 ² 9,138 × 10 ² 1,082 × 10 ³ 1,492 × 10 ³ 6 2,840 ^{× 10 3 4,323 × 10 3 5,449} × 10 3 6,805 × 10 2 8 1,794 × 10 3 5,104 × 10 3 3,353 × 10 3 3,712 × 10

[0025]

[Table 3] Table 3 Culture period (weeks) Ammonia concentration (mM) Test plot A Test plot B Test plot C Test plot D 0 0.25 0.25 0.25 0.25 4 1.00 0.62 0.98 0.45 6 1.11 0.85 1.75 1.24 8 0.96 0.89 2.19 6.41

From Tables 2 and 3, it can be seen from the test plot D having the lowest frequency of seawater exchange that the colony density was the highest up to 4 weeks after the start of the culture, but thereafter, the colony density decreased, and the colony density was 6 weeks after the start of the culture. The ammonia concentration in the eye was 1.24 mM. In test plot C, the colony density increased up to 6 weeks after the start of the culture, but then decreased, and the ammonia concentration from the 6th week to the 8th week after the start of the culture was 1.75 to 2.19 mM. In the test plots A and B, since the ammonia concentration was 1.11 mM or less, it can be seen that the ammonia concentration that does not affect the growth of the mosquitoes is 1.24 mM or less.

EXAMPLE A 4000 liter (approximately 40 cm deep) seawater was placed in a circular seawater tank with a bottom area of 10 m ² , a plastic bag was laid on the inside, and fine sand of a culture substrate (Kumamoto Silica Sand Mining Co., Ltd.) was placed on top of it. , K-8, median particle size: 60 μm) to a depth of 1 cm, and 110 plastic containers made of polyvinyl chloride containing 500 larvae of Itokai (30 × 20 × 10cm) and seawater temperature 1
The dissolved oxygen concentration in the seawater was kept in a saturated state by ventilating the lower two portions of the seawater tank with an air pump within the range of 0 to 20 ° C.

As a feed, a powdered compound feed for hamachi cultivation (Sun Marine KG, manufactured by Mercian Co., Ltd.) (organic carbon content: about 40%) was given. Once a day, they were fed by sprinkling on the water in a sea tank and allowing them to settle naturally. The feeding amount was 40 to 60 g / day. This is approximately 1.6 to 2.4 gC / m per sea tank bottom in terms of organic carbon content.
Equivalent to ² . Whatman, seawater in a sea tank
The filtrate was suction-filtered using a GF / F glass fiber filter, and the ammonia concentration of the obtained filtrate was measured using an automatic nutrient concentration measuring device (Technicon II). After 42 days of culture, the ammonia concentration in seawater is
0.12 mM, which does not affect the growth of Itokai 1.
It was suppressed to 2 mM or less.

Six weeks after the start of cultivation, at the stage when the cells were cultured to a density of about 4 × 10 ⁶ individuals / m ² , the plastic bag laid on the inner surface of the plastic container was pulled up, and the seawater in the plastic bag was properly discarded. The contents of three to four plastic bags were combined into one separate plastic bag and transported to the sludge purification sea area by boat. Divers carried the seabed by hand, smashed plastic bags on the sludge and gently sprayed the sand with the culture substrate sand, and periodically observed the state of the seabed after the spraying. 90
It was confirmed that the water was purified to a level in a healthy region where no decrease in dissolved oxygen was observed after a day.

[0030]

Industrial Applicability According to the method of the present invention, it is possible to cultivate a large amount of a cocoon for purifying organic sludge. The cultured Itokai can be spread on the organic sludge with good workability, and thereby the organic sludge deposited on the seabed of the fish farm can be efficiently purified.

Continued on the front page (72) Inventor Hiroki Takahashi 3-1 Sanraku-cho, Yatsushiro-shi, Kumamoto Inside Mercian Co., Ltd. Yatsushiro Plant (72) Inventor Takako Tokuda 3-1 Sanraku-cho, Yatsushiro-shi, Kumamoto Merchant Yatsushiro Plant F-term (reference) 2B104 AA31 CB23 CB46 4D059 AA09 BA01 BA22 BA25

Claims (8)

[Claims] The present invention relates to a method for culturing to a density of 4 × 10 ⁶ individuals / m ² or more while sprinkling food regularly at a temperature of 5 to 25 ° C. on a substrate and a substrate of a cultivated locust housed in a seawater tank. A method for cultivating a strawberry that purifies organic matter sludge, comprising the steps of: 2. The method for cultivating organic sludge according to claim 1, wherein a plastic container containing the substrate for cultivation of strawberry and strawberry is placed on the bottom of a seawater tank for culturing. 3. The feed is 1.0 gC / m ^{2 in} terms of organic carbon content.
· Day ~2.8gC / m ² · day amounts spraying method for culturing organic sludge purifying Itogokai according to claim 1. 4. The method according to claim 1, wherein the cultivation is performed while maintaining the ammonia concentration in the seawater tank at 1.2 mM or less. 5. The method according to claim 2, wherein the cultivation substrate for cultivation of organic sludge is stored by storing the substrate for cultivation and nesting on a plastic sheet laid on the inner surface of a plastic container. 6. The culture substrate according to claim 1, wherein the culture substrate is fine sand.
The method for cultivating a strawberry in purifying an organic sludge according to the above item. 7. The organic substance according to claim 2 or 5, wherein a plastic container or a plastic container and a plastic sheet having a strength enough to withstand the operation of dispersing the cultured strawberry in an organic sludge seawater area is used. A method for cultivating a strawberry that purifies sludge. 8. A culture substrate containing a high density of a cod that is obtained by the method according to any one of claims 1 to 7,
A method for purifying organic matter sludge, comprising spraying on sediment sludge in a seawater area to be purified, and purifying the organic matter sludge by utilizing the organic matter consumption power of Itokai.