Reverse Osmosis (RO) technology is a membrane separation and filtration technology that uses pressure difference as a power source. It originated from the research of aerospace technology in the 1960s in the United States and gradually transformed into civilian use. Currently, it has been widely used in scientific research, medicine, food, beverage, seawater desalination and other fields.

RO reverse osmosis membranes have pore sizes as small as nanometers (1 nanometer=10-9 (billionth of a meter). Under a certain pressure, H2O molecules can pass through the RO membrane, while impurities such as inorganic salts, heavy metal ions, organic matter, colloids, bacteria, viruses, etc. in the raw water cannot pass through the RO membrane, thus strictly distinguishing between permeable pure water and impermeable concentrated water.

The pure water conductivity of general tap water after RO membrane filtration can reach 5 μ s/cm (RO membrane filtered effluent conductivity=influent conductivity x (1- desalination rate), and the desalination rate of imported reverse osmosis membranes can generally reach over 99%. Within 5 years of operation, it can guarantee over 97%. For those with high requirements for effluent conductivity, two-stage reverse osmosis can be used, and after simple treatment, the effluent conductivity can be less than 2 μ s/cm, which meets the national laboratory level three water standard. After passing through atomic level ion exchange column circulation filtration or EDI equipment, the effluent resistivity can reach 18.2 M Ω· cm, exceeding the national laboratory first level water standard (GB6682-2008).

Preparation of space water, purified water, distilled water, etc; Water for alcohol brewing and reducing alcohol content; Pre preparation of water for industries such as pharmaceuticals and electronics; Concentration, separation, purification, and water preparation in chemical processes; Boiler feedwater desalination soft water; Desalination of seawater and brackish water; Water and wastewater treatment for industries such as papermaking, electroplating, and printing and dyeing.

1. Single stage reverse osmosis system

Single stage reverse osmosis is suitable for water with a conductivity of less than 500 μ s/cm, and the effluent resistivity can reach 0.2-0.1M Ω· cm (conductivity of 10-5 μ s/cm). The desalination rate of single-stage reverse osmosis can reach 90% -99%.

The single-stage reverse osmosis process flow chart is as follows:

A complete reverse osmosis (RO) water treatment system generally consists of a pretreatment section, a membrane treatment section, and a post-treatment section. Based on user requirements and local water quality, the process design includes single-stage reverse osmosis equipment and two-stage reverse osmosis equipment. The main components are selected from well-known brand products, which have superior performance, stability and reliability. The desalination rate of single-stage reverse osmosis equipment is over 97%. The water treated by the first stage reverse osmosis equipment enters the second stage reverse osmosis for further desalination, reducing conductivity, improving water purity, and ensuring that the product water meets the national pure water standard.

1. Raw water: municipal tap water, river water, surface water, and groundwater can be used.

2. Raw water tank (pool): The amount and pressure of water supplied by urban tap water are constantly changing throughout the day, while the production of purified water is basically stable. Therefore, in general, according to the size of the water purification station, a raw water tank or pool needs to be set up to temporarily store and buffer the raw water.

Raw water tanks are generally made of plastic or stainless steel, or reinforced concrete tanks can be used. Adjusting the capacity requires consideration of the raw water utilization rate of the water treatment system, the amount of tap water supplied, and changes in water pressure. Generally, it is recommended to use 1.5-2.5 times the design water volume.

3. Raw water pump: Pressurize the raw water and send it to the pretreatment system, with a pressure generally controlled at 0.3-0.5M Pa, to ensure the required water pressure for the water treatment process. The flow rate is based on the equipment's water production.

4. Preprocessing system

In order to improve the efficiency of reverse osmosis systems, effective pretreatment of raw water is necessary. The appropriate pretreatment depends on the water source, raw water composition, and application conditions, and mainly depends on the source of the raw water, such as well water, surface water, and municipal tap water, which should be treated differently. Usually, the water quality of well water is stable and the possibility of pollution is low, requiring only simple pretreatment such as multi-media filters, activated carbon filters, or scale inhibitors and 5 μ m security filters. However, surface water may be highly contaminated by colloids and microorganisms, requiring a complex pre-treatment system. Other pre-treatment steps are required, including chlorine sterilization, flocculation/coagulation assistance, clarification, bag filter, multi-media filter, activated carbon filtration, dechlorination, acid or scale inhibitor addition, etc.