Reverse osmosis water treatment technology is a high-end water treatment technology that emerged at the end of the 20th century. It has a high desalination rate, a wide range of adaptable water quality and salt content, low chemical consumption, environmental protection, small footprint, a high degree of automation, stable water quality, etc. Features, widely used in water treatment such as ultrapure water preparation, surface water treatment, industrial wastewater reuse, seawater desalination, etc. The water treatment process needs to provide electronic ultrapure water for production, and the reverse osmosis system is the most important desalination treatment system. FRP pressure vessel supplier shares this article for you.
1 Electronic ultrapure water and system water ingress situation
Electronic ultrapure water refers to water that almost completely removes the conductive medium in the water, and removes the non-dissociated colloidal substances, gases, and organic matter in the water to a very low degree. The water has almost no impurities except water molecules (H2O). There are no bacteria, viruses, chlorinated dioxins, and other organic substances. This kind of water production process can be produced by distillation, deionization, reverse osmosis technology or other appropriate supercritical fine technology, and now it is mainly reverse osmosis technology The manufacturing process is relatively common. This project also uses reverse osmosis technology as the main desalination process to prepare electronic ultrapure water.
2 Introduction to the water treatment system
The entire water treatment system is divided into a pretreatment system + reverse osmosis-based desalination system + finishing system + (after heating) + subsequent finishing process, and finally electronic ultrapure water is obtained. The entire water treatment system has a heating function, and the inlet water temperature can be adjusted according to different water temperature needs. The pretreatment system is composed of flocculant and bactericide + automatic multi-media filter + automatic activated carbon filter + pretreatment water tank + pretreatment delivery pump. The reverse osmosis-based desalination system is mainly composed of a primary reverse osmosis system and a secondary reverse osmosis system, especially the primary reverse osmosis system, which is the most important desalination system. Because the reverse osmosis system allows relatively wide salt content in the inlet water and high desalination rate, it can play the main role of desalination and reduce the desalination load of subsequent processing.
Reverse Osmosis Membrane Pressure Vessels
3 Design of a reverse osmosis system
The reverse osmosis system is the core of desalination in the entire water treatment system. The reverse osmosis membrane can remove most of the soluble salt in the water, remove all the colloids and microorganisms in the water, ensure the water quality of the effluent, and provide a high-quality water source for subsequent processes.
4 Operation of the reverse osmosis system
The design of reverse osmosis membrane pressure vessels in the large-scale water treatment project of the plant is feasible. According to the actual application, the operation effect is good and it is suitable for the large-scale electronic ultrapure water of the plant.
5 Cleaning situation of a reverse osmosis system
The pollutants of this set of reverse osmosis systems are mainly organic matter, colloids and microorganisms, but the pollution is not very serious. The standard of chemical cleaning is that when the water flow rate drops by about 10%, chemical cleaning is necessary. Maintenance cleaning is also required when the drop rate is not 10%. In general, the average cleaning cycle is about 3 months. Since the cause of system pollution is organic matter and calcium carbonate fouling, the choice of cleaning agents is mainly for these pollutants. Alkaline washing is mainly based on compound agents. The composition of the compound agent is NaOH (sodium hydroxide) + Na-SDS (sodium dodecylbenzene sulfonate) and other agents, the pH is about 12, and the cleaning time is about 6 h; the cleaning solution for pickling is HCl (hydrochloric acid), the pH is 2 to 3, and the cleaning time is 1 h, The temperature of the cleaning solution is 30 ℃; finally the system uses non-oxidizing bactericide DBNPA for sterilization and cleaning. Single-stage cleaning is carried out during system cleaning, and each stage is cleaned with three-stage flow rates: at the beginning, the flow rate of a single membrane shell is 5 mm3/h (alkaline washing is 1 h, pickling is 10 min); then the single membrane shell is cleaned The liquid flow rate is about 5 mm3 /h for cyclic cleaning (alkali washing 4.5 h, acid washing 40 min function); finally, a large flow is used for flushing, and the flow is about 10 mm3/h (alkaline washing 0.5 h, alkaline washing 10 min) . After each chemical cleaning, turn on the pure water pump for flushing until the cleaning liquid is washed out by pure water.The temperature of the cleaning solution is 30 ℃; finally, the system uses non-oxidizing bactericide DBNPA for sterilization and cleaning. Single-stage cleaning is carried out during system cleaning, and each stage is cleaned with three-stage flow rates: at the beginning , the flow rate of a single membrane shell is 5 mm3/h (alkaline washing is 1 h, pickling is 10 min); then the single membrane shell is cleaned The liquid flow rate is about 5 mm3/h for cyclic cleaning (alkali washing 4.5 h, acid washing 40 min function); finally, a large flow is used for flushing, and the flow is about 10 mm3/h (alkaline washing 0.5 h, alkaline washing 10 min) . After each chemical cleaning, turn on the pure water pump for flushing until the cleaning liquid is washed out by pure water.The temperature of the cleaning solution is 30 ℃; finally the system uses non-oxidizing bactericide DBNPA for sterilization and cleaning. Single-stage cleaning is carried out during system cleaning, and each stage is cleaned with three-stage flow rates: at the beginning , the flow rate of a single membrane shell is 5 mm3/h (alkaline washing is 1 h, pickling is 10 min); then the single membrane shell is cleaned The liquid flow rate is about 5 mm3/h for cyclic cleaning (alkali washing 4.5 h, acid washing 40 min function); finally, a large flow is used for flushing, and the flow is about 10 mm3/h (alkaline washing 0.5 h, alkaline washing 10 min) . After each chemical cleaning, turn on the pure water pump for flushing until the cleaning liquid is washed out by pure water.finally the system uses non-oxidizing bactericide DBNPA for sterilization and cleaning. Single-stage cleaning is carried out during system cleaning, and each stage is cleaned with three-stage flow rates: at the beginning, the flow rate of a single membrane shell is 5 mm3/h (alkaline washing is 1 h, pickling is 10 min); then the single membrane shell is cleaned The liquid flow rate is about 5 mm3/h for cyclic cleaning (alkali washing 4.5 h, acid washing 40 min function); finally, a large flow is used for flushing, and the flow is about 10 mm3/h (alkaline washing 0.5 h, alkaline washing 10 min) . After each chemical cleaning, turn on the pure water pump for flushing until the cleaning liquid is washed out by pure water.finally the system uses non-oxidizing bactericide DBNPA for sterilization and cleaning. Single-stage cleaning is carried out during system cleaning, and each stage is cleaned with three-stage flow rates: at the beginning, the flow rate of a single membrane shell is 5 mm3/h (alkaline washing is 1 h, pickling is 10 min); then the single membrane shell is cleaned The liquid flow rate is about 5 mm3/h for cyclic cleaning (alkali washing 4.5 h, acid washing 40 min function); finally, a large flow is used for flushing, and the flow is about 10 mm3/h (alkaline washing 0.5 h, alkaline washing 10 min) . After each chemical cleaning, turn on the pure water pump for flushing until the cleaning liquid is washed out by pure water.and each stage is cleaned with three-stage flow rates: at the beginning, the flow rate of a single membrane shell is 5 mm3/h (alkaline washing is 1 h, pickling is 10 min); then the single membrane shell is cleaned The liquid flow rate is about 5 mm3/h for cyclic cleaning (alkali washing 4.5 h, acid washing 40 min function); finally, a large flow is used for flushing, and the flow is about 10 mm3/h (alkaline washing 0.5 h, alkaline washing 10 min) . After each chemical cleaning, turn on the pure water pump for flushing until the cleaning liquid is washed out by pure water.and each stage is cleaned with three-stage flow rates: at the beginning, the flow rate of a single membrane shell is 5 mm3/h (alkaline washing is 1 h, pickling is 10 min); then the single membrane shell is cleaned The liquid flow rate is about 5 mm3/h for cyclic cleaning (alkali washing 4.5 h, acid washing 40 min function); finally, a large flow is used for flushing, and the flow is about 10 mm3/h (alkaline washing 0.5 h, alkaline washing 10 min). After each chemical cleaning, turn on the pure water pump for flushing until the cleaning liquid is washed out by pure water.acid washing 40 min function); finally, a large flow is used for flushing, and the flow is about 10 mm3/h (alkaline washing 0.5 h, alkaline washing 10 min) . After each chemical cleaning, turn on the pure water pump for flushing until the cleaning liquid is washed out by pure water.acid washing 40 min function); finally, a large flow is used for flushing, and the flow is about 10 mm3/h (alkaline washing 0.5 h, alkaline washing 10 min) . After each chemical cleaning, turn on the pure water pump for flushing until the cleaning liquid is washed out by pure water.
6 Benefit analysis
The entire water treatment system's fixed asset depreciation, electricity consumption, chemical consumption, and labor costs are calculated. The cost of the first-level reverse osmosis water production is 2.87 yuan/t, and the second-level reverse osmosis water production cost is 4.47 yuan/t. The total cost of ultrapure aquatic water is 6.85 yuan/t, and the price of local tap water is 2.33 yuan/t. This water treatment system provides the factory with a high-quality and stable water source.
7 Conclusion
The reverse osmosis technology has been successfully applied in the large-scale electronic ultrapure water project of the plant, providing a high-quality water source for the subsequent desalination process, ensuring the stability of the subsequent desalination process, and verifying the application of reverse osmosis technology in the electronic ultrapure water project The good performance in China, but also a mature case for reference.
