Compressed air is purified through the air dryer and filters to a certain level for main plant to work with. Air buffer is incorporated for smooth supply of compressed air thus to reduce fluctuation of compressed air source. The plant produces oxygen with PSA (pressure swing adsorption) technology, which is a time proven oxygen generation method. Oxygen of desired purity at 93%±3% is delivered to oxygen buffer tank for smooth supply of product gas. Oxygen in buffer tank is maintained at 4bar pressure.
With a cabinet for small capacity or container for big capacity, all the parts can be involved in, and removable with a vehicle.
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First, test materials
1. A species of sea bream introduced from the Sichuan Aquatic Fish Institute. Its parent is the wild pupa of the Jinjiang River in the upper reaches of the Yangtze River. The relatives must choose individuals older than 3 years old, healthy body, no injury, and normal body surface mucus. The weight of the male is greater than 800g and the star tracking is obvious. The individual female weight is more than 1500g in Jiangsu, Zhejiang, Hubei, Hunan and Anhui. More than 10 provinces (municipalities) and regions, such as Shanghai, Shandong, etc., are essentially natural wild resources, and the amount of resources has increased year by year. This also shows the strong vitality of freshwater crayfish and the greater possibility of successful transplantation. In addition, from the perspective of the distribution of freshwater crayfish, northern China (especially the high-cold regions of Heilongjiang Province) started relatively late in the process of transplanting freshwater crayfish. Although the distribution of wild freshwater crayfish is found in natural water systems, the resources are small and the environment The gradual deterioration of conditions has limited the distribution and resources of freshwater crayfish in the northern regions. Therefore, by improving the transplanted living environment of freshwater crayfish and rehabilitating or improving the transplanted water area, there is a possibility that after transplantation, it is not only easy to obtain a biological effect but also to easily obtain a fishery effect.
Second, the impact of non-biological factors Abiotic factors that affect the freshwater crayfish transplantation include temperature, salinity, and water chemistry.
Freshwater crayfish have strict requirements on the water environment. The adaption temperature is 0°C to 35°C, and the suitable growth water temperature is 20°C to 30°C. When the water temperature is lower than 15°C, the activity is weakened, and the water temperature is lower than 10°C or exceed 35°C. The food intake is significantly reduced. When the water temperature is below 8°C, it enters the wintering period and stops feeding. In winter, it digs through the winter, so freshwater crayfish can naturally overwinter in most areas of China. When the water temperature reaches 18°C ​​or more, broodstock begin to mate, the suitable incubation temperature for fertilized eggs is 22°C to 28°C, the incubation period for water temperature at 18°C ​​to 20°C is 30 days to 40 days, and the water temperature is incubated at 25°C. It only takes 15 days to 20 days. Heilongjiang Province is located between 4323′～5324′N latitude and 12113′-135E longitude. Most regions belong to the middle temperate zone. It is a continental monsoon climate with annual average temperature of -5°C～4°C. The province has more than 10°C duration days for 120 days～ About 150 days, the average temperature in March-September is about 18°C, the number of days in sunshine is from 4449 to 4470 hours, and the actual number of days is from 2400 to 3,000 hours. The sunshine hours in July are the longest and most. 460 hours to 520 hours to meet the needs of freshwater crayfish for survival, growth and reproduction. The author believes that if we fully exploit the heat sources such as hot springs in the northern region and the waste heat of the factory to carry out the breeding and breeding of freshwater crayfish, we can receive better results.
Freshwater crayfish can survive in water with a pH of 5.8 to 8.2 and a dissolved oxygen content of at least 1.5 mg/L. Freshwater crayfish are suitable for growing waters with a pH range of 7.5 to 8.2 and a dissolved oxygen content of more than 3 mg/L. The water transparency is 30cm to 40cm. The pH change of lake water in Heilongjiang province is mostly between 6.8 and 7.7. The salt content of water varies from 37.93mg/L to 365mg/L. The dissolved oxygen content of the water is higher and it can meet the needs of freshwater crayfish better. Need for survival, reproduction, and growth.
Third, the impact of biological factors Biological factors that affect freshwater crayfish transplantation include basic food organisms, pathogenic organisms, competitors, and predator organisms.
Freshwater crayfish are omnivorous animals, all kinds of fresh aquatic plants and benthic animals, mollusks, large zooplankton, fish and shrimp corpses, and similar corpses in the water body are all their favorite food organisms. In addition, freshwater crayfish are also relatively freshwater crayfish. Eat artificially fed bean cake, wheat bran or compound feed. The larvae began to ingest phytoplankton, small larval larvae, rotifers, etc. after the first shelling, but the freshwater crayfish were gluttony and the food was crippled when the diet was insufficient. The soft shells of the oyster shell or just oyster shell were Shrimp is most likely to be eaten. In the natural waters of Heilongjiang Province, the mean value of total nutrient elements in plants is 0.581mg/L～7.281mg/L, and the average phosphorus is 0.021mg/L～1.870mg/L. Most of the waters are eutrophic or supertrophic, and swim in ponds. The amount of plants reached 26.53mg/L~61.94mg/L, the average amount of phytoplankton in lakes was 12.4mg/L, the amount of phytoplankton in reservoirs was 5.79mg/L~24.95mg/L, and the minimum amount of phytoplankton in rivers was 3.06mg. /L～11.76mg/L range; zooplankton has the largest amount of zooplankton, reaching 23.89mg/L, the small reservoir is the second, is about 8.7mg/L, the average amount of zooplankton in the lake is 5.25mg/L, the tributaries of rivers and streams The average amount of zooplankton is 1.68mg/L; there are 173 species of benthos, the average density of each river is 591/m3, the average biomass is 8.71g/m3, and the average lake density is 1550/m3. The average biomass is about 23.37g/m3, the average density of the reservoir is 1319/m3, and the average biomass is 123.1g/m3. In addition, lakes in Heilongjiang Province are mostly plain water bodies (excluding Jingpo Lake), with an average depth of 3m to 5m, and abundant aquatic plants. Therefore, from the point of view of the basic food organisms in water, the waters in Heilongjiang Province can meet the feeding needs of freshwater crayfish.
The freshwater crayfish are thick, thick and dark crustaceans, and the body is covered with a hard chitinous shell. The second step is particularly developed and becomes a great chelation. Male chelators are more developed than females. With a good ability to resist the enemy and avoid enemies, the ability to migrate to new waters and compete with other existing aquatic animals in feed organisms, habitats, breeding sites, etc., is strong, and the waters in the waters of Heilongjiang Province The composition of the fauna is relatively simple and there are few occurrences of fish diseases. Therefore, the resistance encountered in freshwater crayfish transplantation is relatively small, and the transplantation work is easy to succeed.
IV. Several Problems to Be Paid Attention to when Transplanting Freshwater Crayfish
1. Destructiveness of freshwater crayfish. Freshwater crayfish have the habit of playing caves on the surface of the water, and the cave is inclined downwards, with a depth of about 50cm to 80cm. At the same time, the proliferation of freshwater crayfish may pose a threat to the safety of lakes, reservoirs, rivers, etc. Some experts have investigated the life history and living habits of freshwater crayfish in the Dongting Lake area. The survey found that due to some freshwater that escaped, Individual lobsters burrow on levees to survive, and it has severely affected the safety of flood levee facilities in the Lake District.
2. Invasiveness of freshwater crayfish. Freshwater crayfish have very strong feeding capacity and reproductive capacity, and have very low requirements for the growth environment. Therefore, freshwater crayfish are easy to survive in temporary water bodies, and they have a very wide range of food habits, and the establishment of populations is extremely fast. At the same time, they also pose a great threat to fish, crustaceans, aquatic plants and rice in the same waters.
3. Safety of freshwater crayfish culture. Although freshwater crayfish are tender and nutritious, their protein content is 16% to 20%, they are rich in 8 kinds of essential amino acids, low in fat content, and contain more tropomyosin and paramyosin, and shrimp meat. The contents of trace elements such as zinc, iodine and selenium are also higher than those of other foods. Their muscle fibers are delicate and easily digested and absorbed by the human body. The edible part is relatively high, but the freshwater crayfish have strong adaptability and resistance to stress. The water in the water contaminated water can also survive, and the quality of shrimp meat is difficult to guarantee. Therefore, special attention should be paid to the cleanliness of the freshwater crayfish aquaculture. The water area with good water quality should be selected to adopt the pollution-free culture method to reduce the pesticide residue and follow the freshwater crayfish. Safety and health system and HACCP system certification, health registration and daily supervision and management, etc. are good for culture.
Factors Affecting the Transplantation of Freshwater Crayfish in Northern China
The long thin beetle, which is listed in the Red Book of Endangered Animals of China, belongs to the genus Polygonidae, S. striata, and Blattella. It is the fastest growing and largest individual of the carps. Common individuals weigh between 0.2 kg and 0.4 kg. The largest individual body weight is 3.0kg, which is mainly distributed in the upper reaches of the Changjiang River and its tributaries. In order to save endangered species, in recent 10 years many units in China have carried out research on the development and utilization of C. longicornis, conducted seed collection and pond domestication, and tried a series of artificial breeding and seed cultivation, but most of them are Under natural conditions in the south. In 2006, scientific researchers of the Fish Disease Prevention and Control Center of the Institute of Special Fish Research of Heilongjiang Province collaborated with the researchers of the Research Group of the Special Aquaculture Research Unit of the Hejiang Forestry Research Institute of Heilongjiang Province for the first time to carry out indoor artificial propagation tests on C. striata and achieved success.