What is the difference between single-stage reverse osmosis and two-stage reverse osmosis in water treatment equipment

The difference between single-stage and two-stage reverse osmosis is mainly based on the process flow:

Single stage reverse osmosis equipment

Single stage reverse osmosis equipment, also known as first stage reverse osmosis, involves the raw water passing through a pre-treatment system, precision filters, and then high-pressure pumps before being sent to the reverse osmosis device. The directly produced water is called single-stage reverse osmosis.

Characteristics of single-stage reverse osmosis equipment: Single stage reverse osmosis is a practical technology that selectively allows certain components in the solution to pass through under external pressure, thereby achieving the purpose of desalination, purification, or concentration separation; It can remove the majority of ions in water, as well as impurities such as fine particles, bacteria, and organic matter. It is currently an advanced and economical method in water treatment equipment. Single stage reverse osmosis is mainly used for users with good water quality or low water quality requirements.

◆ Dual stage reverse osmosis equipment

Double stage reverse osmosis equipment, also known as secondary reverse osmosis, is a two-stage reverse osmosis preparation system that uses tap water as raw water. It undergoes pre-treatment, security filtration, and then enters a precision filter for filtration. It is pressurized by a first stage high-pressure pump and sent to the first stage reverse osmosis system. The water produced by the first stage reverse osmosis is then pressurized by the second stage high-pressure pump and sent to the second stage reverse osmosis system. The water produced is called dual stage reverse osmosis. Characteristics of dual stage reverse osmosis equipment: It can remove harmful substances such as particles, colloids, organic impurities, heavy metal ions, bacteria, viruses, heat sources, and 90% of dissolved salts from water. The desalination rate of the system can reach over 90%. Dual stage reverse osmosis is mainly used for users with poor water quality or high water quality requirements.

Information source: New Perspectives on Water Treatment