In the previous article, we provided a detailed explanation of the YIME reverse osmosis (RO) pure water system flow diagram and described how the system operates. Now, let's look at how YIME's core product-the RO membrane-actually works.
First, reverse osmosis is essentially the opposite of natural osmosis. In nature, there is a type of membrane called a semipermeable membrane, which allows water to pass through but blocks other solutes. If freshwater and saltwater are separated by such a membrane, water will naturally flow from the freshwater side to the saltwater side, as shown in Figure A. This phenomenon is called osmosis.
As osmosis continues, the water level on the saltwater side rises, generating pressure that eventually inhibits further water flow and establishes equilibrium. This equilibrium pressure is known as osmotic pressure.
Under these conditions, if a pressure greater than the osmotic pressure is applied on the saltwater side, water molecules will be forced to move from the saltwater side through the semipermeable membrane to the freshwater side. This process is called reverse osmosis, as illustrated below.
Using this principle, reverse osmosis can be employed for desalination.
The desalination mechanism of an RO membrane relies on its semipermeable layer, which is covered with numerous tiny pores. The membrane surface selectively adsorbs a layer of water molecules, while salt ions and other solutes are rejected. Ions with higher valence are repelled more strongly. Under the applied reverse osmosis pressure, water molecules flow through the membrane's capillary channels, producing pure water and achieving the removal of salts.
The pores of an RO membrane are smaller than 1.0 nm, enabling it to filter out even small bacteria such as Pseudomonas aeruginosa, as well as various viruses, including influenza virus and meningitis virus, and even pyrogens. Therefore, RO membranes can effectively remove salts, impurities, and microorganisms from water, ensuring that the produced water is safe, clean, and reliable.
This is how YIME RO membranes operate. Additionally, through specific manufacturing techniques, RO membranes can be engineered to be anti-fouling or tailored to perform efficiently under low-pressure or high-pressure conditions.
