CN107509673B - A kind of resource utilization method of intensive prawn aquaculture wastewater - Google Patents

Abstract

The present invention relates to a resource utilization method of intensive prawn culture wastewater, the method comprising: step S1: filtering the wastewater discharged from the intensive pond prawn cultivating with an inclined surface filter screen; step S2: filtering The waste water filtered by the inclined surface filter screen is collected into the waste water storage tank; Step S3: the waste water of the waste water storage tank is transported to the microalgae proliferation tank of the sun shed to cultivate the microalgae; In the pod culture tank, the generated cladocerans or copepods are harvested to supplement the bait for the culture of L. vannamei. Its advantages are as follows: the nitrogen and phosphorus nutrients in the wastewater are used in the food chain of microalgae-zooplankton-prawns to realize the recycling of nitrogen and phosphorus and other nutrients while purifying the eutrophic aquaculture wastewater, which not only protects the The aquaculture water environment has supplemented natural bait for intensive shrimp farming, reducing the cost of shrimp farming feed and improving farming benefits.

Description

A kind of resource utilization method of intensive prawn aquaculture wastewater

technical field

The invention relates to the technical field of resource-based treatment of aquaculture wastewater, in particular to a resource-based utilization method of intensive Litopenaeus vannamei aquaculture wastewater.

Background technique

Because of its fast growth, high meat yield, and wide adaptation to salinity, Litopenaeus vannamei has become the main shrimp culture species in China, South America and Southeast Asia. Since my country introduced aquaculture in the late 1980s, China's Litopenaeus vannamei industry has developed rapidly. According to the statistics of China Fishery Yearbook, my country's marine crustacean aquaculture output in 2016 was 1.4349 million tons, of which more than 40% came from Litopenaeus vannamei, while freshwater The farmed production of L. vannamei was 731,500 tons. However, with the rapid development of my country's Litopenaeus vannamei industry, many problems such as provenance, diseases and breeding patterns have also been exposed. At present, the success rate of traditional earth pond culture of Litopenaeus vannamei is getting lower and lower, and more farmers choose the more intensive and better controllable factory and greenhouse culture mode.

According to the nutritional metabolism characteristics of Litopenaeus vannamei, at present, the feed protein level of the cultured Litopenaeus vannamei in my country is generally 37%-40%. The content accounts for about 18% of the whole shrimp. According to this calculation, the content of protein nitrogen in the feed input during the breeding process that remains in the shrimp body does not exceed 50%, and more than half of the nitrogen enters the water body. Therefore, from the perspective of material flow, the culture of Litopenaeus vannamei is a process that seriously pollutes the aquaculture water. Especially in the intensive aquaculture mode, a large amount of aquaculture wastewater has not been effectively treated, and is directly discharged into the surrounding waters, resulting in serious eutrophication of the water environment and the outbreak of algal blooms, threatening the sustainable development of Litopenaeus vannamei aquaculture and the environment . In the context of the implementation of the "Water Law of the People's Republic of China" revised in 2016, how to reduce and prevent the pollution of aquaculture wastewater to the environment has become an urgent problem to be solved in the development of the aquaculture industry itself.

At present, a variety of methods and processes for treating aquaculture wastewater have been developed at home and abroad, including physical treatment, chemical treatment, biofilm, constructed wetlands, salt-tolerant plants or aquatic plants, and sedimentation-algae adsorption. Comprehensive treatment methods, etc. The above method can play a role in purifying aquaculture wastewater, but generally has a large investment and a low degree of resource utilization of nutrients in wastewater, and has a low degree of application in the cultivation of Litopenaeus vannamei.

In summary, there is an urgent need to invent an intensive resource utilization method of Litopenaeus vannamei aquaculture wastewater, which can not only purify nitrogen and phosphorus nutrients in aquaculture wastewater with high efficiency and low cost, but also reduce nitrogen and phosphorus in wastewater. Phosphorus is utilized as a resource to reduce the cost of bait for prawn farming. However, there is no report on the resource utilization method of this intensive L. vannamei aquaculture wastewater.

SUMMARY OF THE INVENTION

The purpose of the present invention is to aim at the deficiencies in the prior art, provide a kind of resource utilization method of intensive Litopenaeus vannamei aquaculture wastewater, so that a large amount of nitrogen, phosphorus nutrient salts and small amounts of nutrients existing in the intensive Litopenaeus vannamei aquaculture wastewater are provided. Granular organic debris can be converted into biomass of cladocerans or copepods after being filtered by cladocerans or copepods, so as to achieve the goal of purifying aquaculture wastewater, and the generated cladocerans or copepods can be used for harvesting. Supplementary bait for L. vannamei aquaculture.

For realizing the above-mentioned purpose, the technical scheme that the present invention takes is:

A method for resource utilization of intensive Litopenaeus vannamei culture wastewater, characterized in that the method comprises the following steps:

Step S1: filter the waste water discharged from the intensive prawn cultivating pond with an inclined surface filter screen;

Step S2: collecting the waste water filtered by the inclined surface filter screen in Step S1 into the waste water storage tank;

Step S3: the waste water in the waste water storage tank in step S2 is transported to the microalgae proliferation pond in the sun shed to cultivate microalgae;

Step S4: The cultured algal water is transported to the cladoceran or copepod culture tank, and the microalgae in the water are purified by the filter feed of the cladoceran or copepod to generate high-transparency water for recycling or discharge. After harvesting horns or copepods, supplement the bait for L. vannamei aquaculture.

As a preferred technical solution, the inclined surface filter screen in step S1 is composed of two parts, the screen mesh of the first part is 60-80 mesh, and the mesh mesh of the second part is 200 mesh. The horizontal plane is at an angle of 30°-60°, which is adjusted according to the screen area, water flow and the number of suspended particles in the wastewater. The solid waste on the screen is automatically collected into the sewage tank under the action of the water flow.

As a preferred technical solution, the waste water filtered by the inclined filter screen is transported to the waste water storage tank through pipelines. pool.

As a preferred technical solution, the container for microalgae cultivation in the sun shed in step S3 may be a photobioreactor, a simple cement pool or a detachable water tank.

As a preferred technical solution, step S3 includes the following steps:

Step S31, the step of proliferation of microalgae: the proliferation of microalgae needs to be pre-inoculated with beneficial microalgae with strong anti-pollution ability and a certain high temperature resistance in order to directionally regulate the species of microalgae to proliferate. Chlorella (Nannochloropsis oculata) or Tetraselmis subcordiformis or Dunaliella salina, if the wastewater from the aquaculture of Litopenaeus is freshwater, it can be inoculated with Chlamydomonasspp., Chlorella spp.), Scenedesmus (Scenedesmus spp.), Chlorococcum sp., continuous aeration is required during the proliferation of microalgae, and the algal fluid can be transported to cladocerans or copepods after 3-5 days of culture .

As a preferred technical solution, when the wastewater from Litopenaeus vannamei culture has salinity, the species of Calanoid or Moina mongolica are cultivated to filter feed microalgae. When the wastewater is fresh water, Daphnia magna or Daphnia carinata are cultured to filter and feed on algae, and aeration is continued during the culture.

As a preferred technical solution, the volume ratio of the water body in which the microalgae proliferates to the water body in which the cladocerans or copepods are cultivated is 2-3:1.

As a preferred technical solution, the cladocerans or copepods are collected from the cladocerans or copepods in a siphonic method with a 100-mesh sieve bag every day. The daily harvest amount depends on the growth of the population and the amount of depending on the density of algal cells.

The advantages of the present invention are:

1. The resource utilization method of Litopenaeus vannamei culture wastewater of the present invention, the nitrogen and phosphorus nutrients in the wastewater are realized by the food chain of microalgae-zooplankton-prawns, while purifying the eutrophic culture wastewater. The recycling of nutrients such as nitrogen and phosphorus not only protects the aquaculture water environment and ensures the sustainable development of the aquaculture industry, but also supplements natural bait for intensive shrimp farming, reduces the cost of shrimp farming feed, and improves farming benefits.

2. The resource utilization method of Litopenaeus vannamei aquaculture wastewater of the present invention has relatively low input cost and strong technical operability.

Description of drawings

Fig. 1 is a flow chart of a method for resource utilization of intensive prawn culture wastewater according to the present invention.

Detailed ways

The specific embodiments provided by the present invention will be described in detail below with reference to the accompanying drawings.

In this example, the resource utilization test of Litopenaeus vannamei aquaculture wastewater was carried out in a certain Litopenaeus vannamei breeding base in Pudong New Area. The Litopenaeus vannamei aquaculture pond was a cement pond of 50M ² , which was put in at a density of 400/M ² 3 cm of vannamei desalinated standard crude shrimp fry, and the wastewater replaced during the breeding process was purified by referring to the method of the present invention. Please refer to FIG. 1 . FIG. 1 is a flow chart of a method for resource utilization of intensive prawn culture wastewater according to the present invention. A method for resource utilization of intensive prawn culture wastewater, the method comprises the following steps:

Step S1: filter the waste water discharged from the intensive prawn cultivating pond with an inclined surface filter screen;

Among them, the inclined surface filter screen consists of two parts. The mesh of the first part is 60-80 mesh, and the mesh of the second part is 200 mesh. Specifically, it is adjusted according to the screen area, water flow and the number of suspended particles in the wastewater. The solid waste on the screen is automatically collected into the sewage tank under the action of the water flow.

Step S2: collecting the waste water filtered by the inclined surface filter screen in Step S1 into the waste water storage tank;

Among them, the waste water filtered by the inclined filter screen is transported to the waste water storage tank through the pipeline. The waste water storage tank is a cement tank or an earthen tank covered with a plastic film, which is covered with a plastic film to prevent other animals from entering the waste water storage tank.

Step S3: transporting the waste water from the waste water storage tank in Step S2 to the microalgae multiplication pool in the sun shed to cultivate microalgae;

Among them, the container for microalgae cultivation in the sun shed can be a photobioreactor, a simple cement pool or a detachable water tank.

Step S4: The cultured algal water is transported to the cladoceran or copepod culture tank, and the microalgae in the water are purified by the filter feed of the cladoceran or copepod to generate high-transparency water for recycling or discharge. The bait for L. vannamei aquaculture is supplemented after harvesting of the species or copepods.

Among them, the proliferation of microalgae requires pre-inoculation of beneficial microalgae with strong anti-pollution ability and a certain high temperature resistance to directional regulation of the species of microalgae that proliferate. Tetraselmis subcordiformis (Tetraselmis subcordiformis) or Dunaliella salina (Dunaliella salina), etc., if the wastewater from L. vannamei aquaculture is fresh water, it can be inoculated with Chlamydomonas spp., Chlorella spp., Scenedesmus ( Scenedesmus spp.), Chlorococcum sp., etc., continuous aeration is required during the proliferation of microalgae, and the algal fluid can be transported to the cladoceran or copepod culture tank after 3-5 days of culture.

Among them, when the wastewater from Litopenaeus vannamei culture has salinity, the species of Calanoid or Moina mongolica are cultivated to filter feed microalgae, and when the wastewater from Litopenaeus vannamei is fresh water, the cultured Daphnia magna or Daphnia carinata filter-feed algae and are continuously aerated during culture.

Among them, the volume ratio of the water body in which Scenedesmus proliferates and the water body in which the large flea is cultivated is 2-3:1.

Among them, the large fleas are collected from the large flea culture tank by siphoning method every day, and the large fleas are collected by 100-mesh sieve bags. The daily harvest amount depends on the population growth and the density of algal cells in the water body. The harvested large fleas are fed to Vanner In the shrimp culture pond, the bait of the shrimp is supplemented, and the discharged high-transparency water can be discharged.

Implementation Effect:

The transparency, total nitrogen, total phosphorus, ammonia nitrogen and other indicators of the purified aquaculture discharge water have reached the surface water class III water standard. After 90 days of culture, the harvested shrimp yield was 5.8kg/M2, and the cumulative harvest was fed to 53 kg of cladocerans and prawns. The feed coefficient of compound feed is 0.82 in the whole breeding process.

According to a method for resource utilization of Litopenaeus vannamei aquaculture wastewater of the present invention, nitrogen and phosphorus nutrients in wastewater are used in the purification of eutrophic aquaculture wastewater by means of the food chain of microalgae-zooplankton-prawns. At the same time, the recycling of nutrients such as nitrogen and phosphorus is realized, which not only protects the aquaculture water environment, saves water resources, does not produce eutrophic pollution to the surrounding water environment, ensures the sustainable development of the aquaculture industry, and supplements intensive shrimp aquaculture. Natural bait is used to reduce the cost of shrimp farming feed and improve farming efficiency. The method of the present invention has relatively low input cost and strong technical operability.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the method of the present invention, several improvements and supplements can be made, and these improvements and supplements should also be regarded as It is the protection scope of the present invention.

Claims (1)

1. a resource utilization method of intensive Litopenaeus vannamei culture wastewater, is characterized in that, described method may further comprise the steps: Step S1: filter the waste water discharged from the intensive prawn cultivating pond with an inclined surface filter screen; Step S2: collecting the waste water filtered by the inclined surface filter screen in Step S1 into the waste water storage tank; Step S3: the waste water in the waste water storage tank in step S2 is transported to the microalgae proliferation pond in the sun shed to cultivate microalgae; Step S4: The cultured algal water is transported to the cladoceran or copepod culture tank, and the microalgae in the water are purified by the filter feed of the cladoceran or copepod to generate high-transparency water for recycling or discharge. Supplementation of bait for L. vannamei culture after harvest of horns or copepods; The inclined surface filter screen in the step S1 is composed of two parts, the mesh mesh of the first part is 60-80 mesh, the mesh mesh of the second part is 200 mesh, and the inclined plane of the screen mesh is 30°-60° clamped with the horizontal plane. The angle is adjusted according to the screen area, water flow and the number of suspended particles in the wastewater. The solid waste on the screen is automatically collected into the sewage tank under the action of the water flow; The waste water filtered by the inclined filter screen is transported to the waste water storage tank through the pipeline. The waste water storage tank is a cement tank or an earthen tank covered with a plastic film, which is covered with a plastic film to prevent other animals from entering the waste water storage tank; The container for microalgae cultivation in the sun shed in step S3 can be a photobioreactor, or a simple cement pond or a detachable water tank; Step S3 includes the following steps: Step S31, the step of proliferation of microalgae: the proliferation of microalgae needs to be pre-inoculated with beneficial microalgae with strong anti-pollution ability and a certain high temperature resistance in order to directionally regulate the species of microalgae to proliferate. Nannochloropsis oculata or Tetraselmis subcordiformis or Dunaliella salina, if the wastewater from Litopenaeus prawn culture is fresh water, inoculated with Chlamydomonas spp., Chlorella spp. .), Scenedesmus spp., Chlorococcum sp., continuous aeration is required during the proliferation of microalgae, and the algal water is transported to cladocerans or copepods after 3-5 days of culture; When the wastewater from Litopenaeus vannamei aquaculture has salinity, cultivate species of Calanoid or Moina mongolica to filter feed microalgae. (Daphniamagna) or Daphnia carinata filter-feed algae with continuous aeration during cultivation; The volume ratio of the water body for microalgae proliferation to the water body for cladoceran or copepod culture is 2-3:1; Harvest from the cladoceran or copepod culture tank every day, adopt the siphon method, and collect the cladoceran or copepod with a 100-mesh sieve bag. The daily harvest amount depends on the growth of the population and the density of algal cells in the water body. .

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