Disinfection of pig farms refers to the use of physical or chemical methods to kill pathogenic microorganisms or inactivate them to prevent and eliminate pig infectious diseases. At present, the cost of pig feeding is increasing, and the reason for this phenomenon is not only the increase of feed cost, but also a very important reason is the low survival rate and substandard production performance. The key to improve the survival rate and production performance is management, and the foundation of pig farm management is disinfection. At present, most pig farms in China regard disinfection as an ordinary link, but often the more common link is not paid attention to, so most pig farms have a weak sense of disinfection, do not pay attention to disinfection management in the breeding process, ignore the importance of disinfection, and focus on the delivery of vaccines and drugs.
At present, the disinfection of drinking water in pig farms usually uses oxidants to disinfect it. The disinfection methods are divided into liquid chlorine, sodium hypochlorite solution and on-site electrolytic sodium hypochlorite. The decay rate of residual chlorine of liquid chlorine is faster, but the transportation and storage conditions are poor, which is easy to pollute the environment and unsafe. Purchased sodium hypochlorite solution in addition to volatilization or crystallization in the process of transportation and storage, there is no great risk, but the freight is higher; The safety and storage of sodium hypochlorite prepared on site are the best, the raw materials are salt and water, the cost is low, the current production is used, and the risk is low. In terms of control of disinfection by-products, the contents of trichloromethane and haloacetic acid in sodium hypochlorite disinfection water were low, and the number of bacterial colonies and heterotrophic bacteria did not exceed 1CFU/mL. Therefore, the use of on-site electrolysis to prepare sodium hypochlorite solution has gradually been recognized and promoted in the livestock and poultry industry, and the selection of BLUEWAV sodium hypochlorite generator for on-site preparation has more advantages.
The disinfection principle of sodium hypochlorite
The bactericidal principle of sodium hypochlorite is mainly: sodium hypochlorite (NaClO) hydrolyzes to form hypochlorous acid (HCIO), and then HCIO decomposes to produce new ecological oxygen. The new ecological oxygen is highly oxidizing and can degrade the proteins of viruses and bacteria. Therefore, the new ecological oxygen can eliminate various bacteria without leaving odor, such as salmonella, Escherichia coli, staphylococcus, etc., and also has a good effect on inhibiting the germination of fungi such as penicillium, trichomyces and aspergillus. In addition, the test shows that electrolytic water has the function of killing virus. According to the chemical determination, pH value has a certain influence on the hydrolysis of NaCl0. When pH >9.5, the HCI0 produced by the hydrolysis of NaCl0 will decrease the disinfection effect. Generally, the pH value of water is greater than 6 but less than 8.5, so NaCl0 can almost be completely hydrolyzed into HCI0 in water, and its hydrolysis efficiency is greater than 99.99%. In the process of sterilizing and killing the virus, HCIO not only has an effect on the cell wall of the bacteria and the protein shell of the virus, but also because HCI0 does not carry charge and the molecule is small, it can enter the bacteria (virus) body and the nucleic acid, protein and enzyme oxidation reaction of the bacteria (virus) body, so that the pathogen will die out.
Preparation principle of sodium hypochlorite
Sodium hypochlorite is a broad spectrum disinfection method for water treatment, which is mainly obtained by electrolysis of saturated salt water. The sodium hypochlorite solution produced by the chlor-alkali plant is colorless or yellowish-green solution, containing 5% to 15% effective chlorine, but the high concentration of sodium hypochlorite solution is very easy to decompose and volatilize, affecting the sterilization and disinfection effect. Generally, the solution needs to be used up after a few weeks of production, so the storage conditions are very strict, the requirements of infrastructure equipment construction are increased, and the production cost is increased. High concentration sodium hypochlorite solution, it is difficult to control the amount of chlorine added, and easy to cause the dosing hole obstruction; High concentration of sodium hypochlorite has super corrosive, which will lead to inconvenient transportation and great security risks; In general, the purity of sodium hypochlorite solution produced by chlor-alkali factory is not high, the content of alkali and harmful impurities is high, and it is not suitable for promoting life and animal husbandry water.
The on-site preparation of sodium hypochlorite using sodium hypochlorite generator can well solve the above shortcomings of direct use of finished sodium hypochlorite in sodium hypochlorite generator, using the natural reaction of the solution and the electrolytic reaction in the electrolytic cell, industrial refined salt can be reoxidized to sodium hypochlorite solution under the action of electric field.
Composition and principle of curtain type ultrafiltration sodium hypochlorite generator
The equipment in this paper mainly consists of sodium hypochlorite generator and curtain ultrafiltration membrane group structure at the back end.
Composition of sodium hypochlorite generator
The main components of the sodium hypochlorite generator system are :3% salt water configuration system (including filtration and soft water, distribution pump, saturated salt water metering pump) sodium hypochlorite generator host (including intelligent control system, electrolytic system, pickling, hydrogen discharge system), sodium hypochlorite dosing system (including finished sodium hypochlorite solution storage tank, frequency conversion dosing pump) control system (including PLC control center, liquid Crystal display, remote monitoring, residual chlorine detector). Sodium hypochlorite generator system operation process: Tap water through the water inlet first through the water softening system to remove calcium, magnesium plasma and other water impurities in the water, divided into two output, one supply to the dissolved salt filtration system, improve the purity of salt water to form pure salt water, the other connected with the outlet of the dissolved salt filtration system, mixed with pure salt water into the diaphragm electrolytic module. A 3% brine electrolyte is formed, and the prepared electrolyte enters the electrolytic cell for electrolytic reaction to generate finished sodium hypochlorite solution and store it. After receiving the dosing point dosing signal, the dosing pump is started and the sodium hypochlorite disinfectant is added into the main water for drinking water disinfection.
Curtain type ultrafiltration membrane group structure at the back end of sodium hypochlorite generator
In order to further ensure the safety of water quality, a curtain ultrafiltration membrane group is set up after the use of the sodium hypochlorite generator.
For the raw water of the farm, the proprietary submerged curtain membrane purification technology is used, and the unique membrane structure and combination process are designed. Combined with automatic gas-water combined washing and enhanced backwashing function, the sodium hypochlorite solution is filtered out, and the purification effect is better.
Test and result analysis
Sodium hypochlorite generator system technical specifications
The sodium hypochlorite generator is selected to adjust the pH of the water source to form a complete set of equipment, which is applied to the pig farm drinking water system with a daily treatment water volume of not less than 50t, the main parameter indicators are 1) the turbidity of the outlet :≤ 0.5NTU; 2) Outlet chromaticity (platinum cobalt chromaticity unit):≤15; 3) Chlorine gas and free chlorine preparations (free chlorine): factory water allowance > 0.3mg, factory water limit < 4mg; 4) Microbiological index /(MPN/(100mL), or CFU/(100mL)): Total coliform, thermostable Coliform and Escherichia coli groups shall not be detected; 5) Total number of colonies (CFU/mL):≤100.
Test water quality detection
After the experiment, the system in a pig farm application effect is remarkable, pig water quality has been significantly improved, the reuse rate of pig water reached more than 90%, compared with the traditional farming method, greatly reduce the demand for new water, reduce the production cost of the farm, but also conducive to environmental protection and sustainable development.
At present, only a part of small pig farms use sodium hypochlorite prepared on site for water disinfection, and it has not been widely used in large pig farms. The design process in this paper has certain promotion significance in small-scale experimental application in pig farms. At the same time, the pig farm users gave feedback on some relevant suggestions for subsequent improvement: the raw water treated by the system equipment of about 50t is smaller than that of large pig farms; Follow-up studies need to increase the water purification treatment capacity of equipment to meet the needs of large farms: Since the concentration control of sodium hypochlorite will affect the probiotic activity of pig intestinal tract after the disinfection of ultrafiltration equipment with sodium hypochlorite, it is necessary to improve the precision control precision of sodium hypochlorite dosage. The corresponding table of sodium hypochlorite dosage should be equipped according to the scale of pig farm, raw water standards and environmental requirements, and the equipment should be intelligent Monitoring and response disposal functions. In the later stage, in response to the above feedback, it is necessary to deeply study the optimization design and comprehensively consider various requirements to improve the intelligence level of system equipment. The application system of hypochlorous acid in disinfection and deodorization of pig farms has been very mature, and there may be room for exploration of sodium hypochlorite. BLUEWAV Sodium hypochlorite generator, plug and play, modular design, easy installation, brine required accuracy as low as 89%, contact us to learn more!
Article reprinted from Mechanical & Electrical Technology, Editorial Office Email, Issue 03, 2024.