Application And Comparison Of Sterilization Methods In Purified Water System

In order to explore the effect of different sterilization methods applied in the purified water system, three sterilization methods including chlorine dioxide sterilization method, ozone sterilization method and pasteurization method were selected. After clarifying the specific operation of each sterilization method, On the basis of raw material preparation methods and sterilization properties, the purified water system disinfectant residue, sterilization effect and bacterial challenge were compared in the form of experiments. The results obtained through the experiment prove that the three sterilization methods have their own advantages in the comparison of different sterilization properties. In practical applications, the purification needs of the purified water system should be integrated, and the sterilization conditions should be combined to rationalize the sterilization methods. Choose to ensure that on the basis of meeting the purified water standard, the cost of sterilization is reduced and the quality of sterilization is improved.

Under normal conditions, the water body will contain different amounts of Na ions and Cl ions, but in some chemical research fields, it is not allowed to contain ions in the laboratory water body, so it is necessary to use some special means when preparing the water body. The deionization treatment of water body, the water body obtained in this way can be called purified water. A necessary step in the process of preparing purified water is to sterilize the water introduced into the system. In order to improve the preparation effect of the purified water system, the following will analyze the use of the three mold methods in the preparation process, and combine different The sterilizing effect of the method should be mastered, and the sterilizing method with the best effect should be mastered and promoted.

Part 1 Sterilization Method In Purified Water System

1.1 Chlorine Dioxide Sterilization Method

In the sterilization process, chlorine dioxide mainly plays the role of oxidation instead of chlorination, so no organic chlorides will be produced, let alone chloramines. This sterilization method can have a good effect on the sterilization of inactivated viruses and cryptosporidium existing in the purified water system. At the same time, the characteristics of sterilization in practical applications using this sterilization method will not be affected by the pH value of the sterilization environment. During the sterilization process, the chlorine dioxide that has not played a sterilizing effect will remain in the solution with its original performance, so as to prolong the sterilizing effect and have a strong oxidizing effect.

In order to realize the sterilization of the purified water system based on chlorine dioxide, it can be integrated into the pure hydration system to realize the sterilization of the water body.

1.2 Ozone Sterilization Method

Ozone is also called O3. From the perspective of chemical molecules, ozone belongs to the allotrope of oxygen ions. When ozone is applied to the sterilization of pure hydration system, ozone can effectively destroy or decompose the outer wall structure of cells, and quickly Diffuse inside the cell to oxidize glucose in the cell fluid. It can also directly react with viruses and bacteria to destroy cell structure, RNA and DNA. In this way, it can destroy macromolecular polymers such as proteins, inhibit the metabolism and reproduction of bacteria in water, and achieve the goal of protecting water. purification effect.

When using ozone for water disinfection, it should be considered that the half-life of ozone is 30.0min~60.0min, and the molecular structure of ozone has the characteristics of poor stability and easy decomposition. Therefore, it is impossible to store ozone as a conventional product material. Before sterilization, timely preparation is carried out on site. The ozone disinfection solution preparation device and the pipeline sterilization device are described.

Prepare the ozone sterilizing solution of the purified water system, and flow the prepared solution into the purified water system through the pipeline to purify the water body. In this process, it should be noted that after the ozone solution has been eliminated, the excess ozone solution remaining in the water body or put into use needs to be removed to avoid the impact of the residual ozone solution on the quality of the purified water prepared. Usually, it is necessary to control the residual ozone aqueous solution content in purified water to <0.005mg/L.

Based on the theoretical level, activated carbon, chemical catalysis, thermal destruction, ultraviolet radiation and other methods can be used to remove ozone residues. And the effective treatment method is ultraviolet radiation method. The specific operation method is: install a UV lamp that can radiate ultraviolet light at the first water inlet position in the purified water pipeline system. Before using water or starting to produce water, you need to turn on the UV lamp. When the purified water is not produced, directly Just turn off the UV light. According to a lot of practice and research results, to eliminate 1.0mg/L of residual ozone in water, it is necessary to ensure that the irradiation amount of the ultraviolet light is >9.0×104μW·S/cm2.

1.3 Pasteurization Method

Pasteurization refers to the heat treatment of the water to be purified in the purified water system. After a period of continuous heat treatment, it can effectively kill some viruses and bacteria in the water and avoid the continuous fermentation of microorganisms in the water. This process can also be regarded as a process of destroying a certain microbial structure in the water body.

When using the pasteurization method to treat mold in the purified water system, it is necessary to heat the water body to 80.0 degrees Celsius under the heating device. After maintaining this temperature for a period of time, the disinfected water body will be pre-cooled in the pipeline, and finally from the The water flows out from the outlet. This process is relatively simple, but it is a process that can effectively treat bacteria by heating.

Part 2 Comparison Of Three Sterilization Methods

2.1 Comparison Of Disinfectant Residues In Purified Water Systems

After completing the research on the use of the three sterilization methods, this chapter will analyze the application effect of the sterilization methods from the perspective of disinfectant residues in the purified water system during the disinfection process.

When using the chlorine dioxide sterilization method for sterilization, it is necessary to drain the chlorine dioxide disinfection water in the storage tank and pipeline, and then re-prepare about 200.0 liters of new water, and circulate it in the purified water system for 15.0min~25.0min , take water at the terminal return port of the system, control the water intake to 50.0ml, and test the conductivity of the water body. On this basis, follow the same operation steps to flush the sterilization pipeline until the conductivity test result of the water meets the condition of 1.0×105Ω·cm, and record the flushing time in this process.

When using ozone to sterilize the purified water system, complete the sterilizing treatment according to the above discussion. During the sterilization process, the flow-limited ozone disinfectant in the purified water system can be completely decomposed in the water. Therefore, for the comparison of its residual problems, the time for complete decomposition is selected as the evaluation index. The shorter the complete decomposition time, the less disinfectant remains in the purified water system; and vice versa. During the experiment, it is also required to complete the preparation of 200.0 liters of purified water. During the preparation process, the circulating water pump was turned on and continued to circulate in the pipeline for 20 minutes, and water samples were obtained at three random locations. After the supply of ozone is stopped, the ultraviolet lamp installed inside the pipeline is turned on, and the decomposition of ozone in water is completed. Finally, use the iodometric titration method at the total backwater port to complete the detection of ozone residues. When ozone cannot be detected, record this time and time, and use this time to subtract the time of adding ozone to obtain the complete decomposition time of ozone. , and use this value as the time for the disinfectant residue to decompose.

Finally, according to the pasteurization method, the purified water is heated to above 80°C, and the heating time is controlled within the range of 50min~60min, and the cycle holding time is 50min to complete the sterilization under high temperature conditions. The entire disinfection and sterilization process does not require disinfectant, so there is no residue after disinfection and sterilization. It only needs to cool and drain the water, and then re-make the water for use.

Through the above experimental operations, the comparison of disinfectant residues in the sterilization process of the three sterilization methods was completed. Through the analysis and comparison of chlorine dioxide flushing time consumption, ozone decomposition time consumption and pasteurization clear residual time, the higher the three time index values The larger the value, the more difficult it is to remove the residues. The order of the severity of the disinfectant residues of the three sterilization methods from light to heavy is: pasteurization<ozone<chlorine dioxide.

2.2 Comparison Of Sterilization Effect

On the basis of the above experimental content, the effects of the three sterilization methods were compared. After the three methods are sterilized, the killing rate of a certain bacterium is selected as the evaluation index. The higher the killing rate, the better the sterilization effect, and the lower the killing rate, the worse the sterilization effect. .

2.3 Bacterial Challenge Comparison

After completing the comparison of disinfectant residues and sterilization effects in purified water systems for the three sterilization methods, the bacterial challenge was compared. Still on the basis of the above experiments, the exploration of this performance is carried out. Select the killing rate mentioned above in this article as the evaluation index, change the experimental variables, and record the killing rates under different concentrations of the three disinfectants. Staphylococcus aureus was still selected as the experimental bacteria. During the experiment, rapid measurement was taken and circulated for 20 minutes, and the solution from the total return port was taken and placed in the test tube. Add the solution to be sterilized with a bacterial content of 0.5ml to the bacterial suspension of 5×105/ml~5×106/ml, and record the three sterilization methods under different killing rates after reaching the specified time for sterilization The concentration of the sterile solution.

The comprehensive analysis concluded that chlorine dioxide was better than ozone and better than pasteurization for the bacteria challenge of the three sterilization methods. Through the above research in this paper, the performance indexes of three different sterilization methods are compared. It can be seen from the experimental results that the three sterilization methods each have different advantages. However, during the experiment, the cost of each sterilization method was not considered, so in the follow-up research, the cost of achieving the ideal sterilization effect will be compared from an economic point of view. At the same time, during the operation of the purified water system, the sterilization method should be reasonably selected in combination with the actual purification needs and economic conditions.

Part 3 Conclusion

Purified water refers to water bodies whose resistivity is >1.0×105Ω·cm when the ambient temperature is >25 degrees Celsius, and such water bodies can also be defined as desalinated water bodies or deionized water bodies. Purified water system refers to a system based on comprehensive treatment methods such as ion treatment, distillation, and reverse osmosis to prepare medicinal water. The prepared water is colorless and odorless. After testing the water, it is found that it does not contain any form of Addition of reagents present. In order to achieve high-efficiency preparation of purified water, this paper studies its application mode and application effect in the purified water system from three aspects: chlorine dioxide sterilization method, ozone sterilization method, and pasteurization sterilization method . The effects of the three different sterilization methods are different in practical applications, but in practical applications, all of them can achieve better sterilization and antivirus effects. Therefore, in the process of preparing purified water, different sterilization treatment methods can be selected in combination with the actual needs of pharmaceutical manufacturers, so as to realize the preparation of purified water and ensure high efficiency and high level of preparation of pharmaceutical production water.