Chlorine dioxide (C102) is currently recognized internationally as an excellent, most effective bactericide, food preservative, mildew deodorant and water quality and air purifier. The World Health Organization has listed it as the fourth generation of high efficiency and safety. The disinfectant was approved by the United States Environmental Protection Department, food and drug management department, and agricultural management department in 1983. Chlorine dioxide, as a disease-preventing disinfectant for aquaculture, has excellent bactericidal and disinfecting properties for fish and shrimp, and has a strong killing effect on pathogenic microorganisms, viruses, and spores transmitted in water bodies. However, the speed of promotion and application in aquaculture production in China is slow, and the actual use effect is not very satisfactory. The reason for this is that due to the late introduction of this technology in China, production technology and output are still far from meeting the needs of practical applications; second, there are still certain errors in the promotion of use. With the continuous improvement of China's scientific and technological level, a large number of chlorine dioxide products that are easy to use and reasonably priced are on the market. Chlorine dioxide is bound to become the leading product of the disinfection and sterilization market in the 21st century. While actively promoting the application of chlorine dioxide, aquaculture science and technology workers should also pay attention to the following issues in accordance with the characteristics of aquaculture:
1, the scope of application of chlorine dioxide Chlorine dioxide is an oxidizing disinfectant, the killing effect on pathogenic microorganisms is broad-spectrum, and is not easy to produce resistance, its bactericidal effect is affected by changes in salinity and pH value Small, it can meet the needs of marine aquaculture and freshwater aquaculture, and can be used for the disinfection and sterilization of fishing gear, aquaculture water and aquaculture products in vitro in aquaculture production.
In terms of the use of aquaculture water, theoretically speaking, it is highly effective and low-toxic to sterilize and sterilize the cultured organisms. It can prevent and control almost all bacterial, fungal and spore diseases, and can also destroy phenol, hydrogen sulfide, and cyanide in the culture water. Many other organic substances reduce the content of THM, increase the amount of dissolved oxygen in water, and improve the quality of cultured water while preventing disease.
However, considering the cost-effectiveness, at present, the production cost of about 2% of stabilized chlorine dioxide is about 1,000 yuan/t, and the usage price per mu of water surface is about 6-10 yuan. In terms of water disinfection, it is mainly suitable for pond aquaculture, intensive aquaculture, and industrialized recirculating aquaculture. It is particularly suitable for aquaculture and special aquaculture.
Considering the production methods of aquaculture, due to the oxidizing ability of chlorine dioxide, it can also kill plankton in the water while killing, reduce the primary productivity in the water and affect the yield, so it is mainly based on natural food. In the aquaculture water body, it is not suitable to promote and apply it, and it is mainly applicable to the culture method based on artificial bait.
2, the use of chlorine dioxide concentration At present, a large number of tests still remain at the level of the laboratory, there is a certain distance with the actual aquaculture production. Due to improper use, in the use of aquaculture production, especially in water disinfection and disinfection often fails to achieve the desired purpose, which seriously dampened the enthusiasm of the use, some people even suspected that the excellent performance of chlorine dioxide, greatly affect the two The further application of oxidized chlorine.
In response to these problems, the authors believe that after repeated tests, the chlorine dioxide concentration is within the range of 0.2-0.5 mg/L, the sterilization effect is very satisfactory, and there is no phenomenon of fish and shrimp repellent. The test results are basically the same as those of other scholars. The results are consistent. However, after field observation and analysis of aquaculture farms, it is believed that the problem lies in the use of concentrations. The first is that the aquaculture farms are relatively extensive in production, the analysis equipment is simple, some units do not even have analysis equipment, and there is a serious lack of necessary techniques and means for analysis and testing. Because the stability of chlorine dioxide has not been completely solved, the product is partially lost during transportation and storage, and the actual content is inconsistent with the manufacturer's label concentration. Second, due to the differences in production conditions such as aquaculture environment and species, especially the instantaneous consumption of chlorine dioxide in the culture water, and the estimation error of the used water volume, it is difficult to use the calculation amount to ensure the accuracy of the application concentration. As a result, the actual application concentration in the disinfecting water body greatly exceeds the limit it should have.
The author carried out some experiments and added the same concentration of chlorine dioxide solution in different culture water of 1000 m1, and determined them by chlorophenol red colorimetry. The results showed that the aquaculture water had different consumption of chlorine dioxide. Due to the difference in the fat and thinness of the aquaculture water and the difference in the dissolved oxygen, the actual concentration of the chlorine dioxide was quite different. For the sample with a theoretical calculation of 0.2 mg/L chlorine dioxide concentration, the lowest measurement result is less than 0.1 mg/L. If this concentration is added to the bottom pond consumption of aquaculture ponds and the adsorption of cultured organisms, etc. The effect of sterilization can be imagined.
The author proposes that in farms with testing conditions, the necessary concentration of chlorine dioxide should be detected in the disinfected water body and the concentration of use should be adjusted in time. For non-testing farms, they should be treated differently according to the actual situation of the water body: for the water with low density, clear water, and high dissolved oxygen, the calculated chlorine dioxide concentration is 0.2 mg/L; In the general water body, the chlorine dioxide concentration is calculated to be 0.2-0.3 mg/L; for the water body with high-density fertilizer, dark green water and dissolved oxygen, the calculated chlorine dioxide concentration is 0.3-0.4 mg/L. . Such recommended doses can basically meet the requirements for safe and effective disease prevention and disinfection under general aquaculture production conditions, but for the application of hatchery, breeding period and sensitive special culture, the necessary experimental research is still required. Further research will be conducted in future work.
3, the use of chlorine dioxide Chlorine dioxide as a gas, its poor stability, for the production, transportation and use of security, are generally made of liquid or solid packaging separately, use and then mix. Chlorine dioxide products usually contain alkaline stabilizers such as sodium bicarbonate, sodium percarbonate, sodium borate and sodium perborate. They need to be activated by hydrochloric acid, citric acid and other acid activators before they are used, and released after activation. Chlorine dioxide can play its due role. Ventilation should be taken care of during the activation process. The operator should work at the windward position to prevent chlorine dioxide from escaping and causing poisoning. Before use, the amount must be calculated in advance, blended by the amount and stirred evenly. After the activation is completed, it is fully diluted and put into use. The theoretical activation time is 10 minutes, effective within 48 hours. When used in aquaculture production, it is recommended that it be activated for about half an hour. It is appropriate to use it within half a day to prevent waste of chemicals due to improper use, and it is difficult to exert the excellent performance of chlorine dioxide disinfection and disease prevention. In addition, when dipping and disinfecting, according to the concentration of a good disinfectant, to fully stir even before they can put the fish and shrimp being disinfected; when the water body is disinfected, the prepared disinfectant should be diluted after a large number of evenly spilled, not dial Movable surface, to prevent the local water concentration is too high, resulting in discomfort and even poisoning fish and shrimp.
1, the scope of application of chlorine dioxide Chlorine dioxide is an oxidizing disinfectant, the killing effect on pathogenic microorganisms is broad-spectrum, and is not easy to produce resistance, its bactericidal effect is affected by changes in salinity and pH value Small, it can meet the needs of marine aquaculture and freshwater aquaculture, and can be used for the disinfection and sterilization of fishing gear, aquaculture water and aquaculture products in vitro in aquaculture production.
In terms of the use of aquaculture water, theoretically speaking, it is highly effective and low-toxic to sterilize and sterilize the cultured organisms. It can prevent and control almost all bacterial, fungal and spore diseases, and can also destroy phenol, hydrogen sulfide, and cyanide in the culture water. Many other organic substances reduce the content of THM, increase the amount of dissolved oxygen in water, and improve the quality of cultured water while preventing disease.
However, considering the cost-effectiveness, at present, the production cost of about 2% of stabilized chlorine dioxide is about 1,000 yuan/t, and the usage price per mu of water surface is about 6-10 yuan. In terms of water disinfection, it is mainly suitable for pond aquaculture, intensive aquaculture, and industrialized recirculating aquaculture. It is particularly suitable for aquaculture and special aquaculture.
Considering the production methods of aquaculture, due to the oxidizing ability of chlorine dioxide, it can also kill plankton in the water while killing, reduce the primary productivity in the water and affect the yield, so it is mainly based on natural food. In the aquaculture water body, it is not suitable to promote and apply it, and it is mainly applicable to the culture method based on artificial bait.
2, the use of chlorine dioxide concentration At present, a large number of tests still remain at the level of the laboratory, there is a certain distance with the actual aquaculture production. Due to improper use, in the use of aquaculture production, especially in water disinfection and disinfection often fails to achieve the desired purpose, which seriously dampened the enthusiasm of the use, some people even suspected that the excellent performance of chlorine dioxide, greatly affect the two The further application of oxidized chlorine.
In response to these problems, the authors believe that after repeated tests, the chlorine dioxide concentration is within the range of 0.2-0.5 mg/L, the sterilization effect is very satisfactory, and there is no phenomenon of fish and shrimp repellent. The test results are basically the same as those of other scholars. The results are consistent. However, after field observation and analysis of aquaculture farms, it is believed that the problem lies in the use of concentrations. The first is that the aquaculture farms are relatively extensive in production, the analysis equipment is simple, some units do not even have analysis equipment, and there is a serious lack of necessary techniques and means for analysis and testing. Because the stability of chlorine dioxide has not been completely solved, the product is partially lost during transportation and storage, and the actual content is inconsistent with the manufacturer's label concentration. Second, due to the differences in production conditions such as aquaculture environment and species, especially the instantaneous consumption of chlorine dioxide in the culture water, and the estimation error of the used water volume, it is difficult to use the calculation amount to ensure the accuracy of the application concentration. As a result, the actual application concentration in the disinfecting water body greatly exceeds the limit it should have.
The author carried out some experiments and added the same concentration of chlorine dioxide solution in different culture water of 1000 m1, and determined them by chlorophenol red colorimetry. The results showed that the aquaculture water had different consumption of chlorine dioxide. Due to the difference in the fat and thinness of the aquaculture water and the difference in the dissolved oxygen, the actual concentration of the chlorine dioxide was quite different. For the sample with a theoretical calculation of 0.2 mg/L chlorine dioxide concentration, the lowest measurement result is less than 0.1 mg/L. If this concentration is added to the bottom pond consumption of aquaculture ponds and the adsorption of cultured organisms, etc. The effect of sterilization can be imagined.
The author proposes that in farms with testing conditions, the necessary concentration of chlorine dioxide should be detected in the disinfected water body and the concentration of use should be adjusted in time. For non-testing farms, they should be treated differently according to the actual situation of the water body: for the water with low density, clear water, and high dissolved oxygen, the calculated chlorine dioxide concentration is 0.2 mg/L; In the general water body, the chlorine dioxide concentration is calculated to be 0.2-0.3 mg/L; for the water body with high-density fertilizer, dark green water and dissolved oxygen, the calculated chlorine dioxide concentration is 0.3-0.4 mg/L. . Such recommended doses can basically meet the requirements for safe and effective disease prevention and disinfection under general aquaculture production conditions, but for the application of hatchery, breeding period and sensitive special culture, the necessary experimental research is still required. Further research will be conducted in future work.
3, the use of chlorine dioxide Chlorine dioxide as a gas, its poor stability, for the production, transportation and use of security, are generally made of liquid or solid packaging separately, use and then mix. Chlorine dioxide products usually contain alkaline stabilizers such as sodium bicarbonate, sodium percarbonate, sodium borate and sodium perborate. They need to be activated by hydrochloric acid, citric acid and other acid activators before they are used, and released after activation. Chlorine dioxide can play its due role. Ventilation should be taken care of during the activation process. The operator should work at the windward position to prevent chlorine dioxide from escaping and causing poisoning. Before use, the amount must be calculated in advance, blended by the amount and stirred evenly. After the activation is completed, it is fully diluted and put into use. The theoretical activation time is 10 minutes, effective within 48 hours. When used in aquaculture production, it is recommended that it be activated for about half an hour. It is appropriate to use it within half a day to prevent waste of chemicals due to improper use, and it is difficult to exert the excellent performance of chlorine dioxide disinfection and disease prevention. In addition, when dipping and disinfecting, according to the concentration of a good disinfectant, to fully stir even before they can put the fish and shrimp being disinfected; when the water body is disinfected, the prepared disinfectant should be diluted after a large number of evenly spilled, not dial Movable surface, to prevent the local water concentration is too high, resulting in discomfort and even poisoning fish and shrimp.
Goji Seed Oil,Fresh Goji Berries,Goji Capsule
Goji Seeds Co., Ltd. , http://www.chdriedgoji.com