We all know that the filtration accuracy of RO membrane is 0.1nm (i.e. 0.0001) μ m) It can filter out bacteria, heavy metals and plasma in water.

Then the problem comes. Benzene molecules can be killed at about 0.5nm and Ca + ions can be killed at about 0.3nm. We can fully understand it.

But when I see that the molecular size of Baidu Shangshui is 0.324nm, how does the RO membrane with a filtration accuracy of 0.1nm filter water? In principle, it can't pass at all? Did you pierce the membrane?

Speaking of reverse osmosis membrane, let's talk about osmosis membrane first. Osmotic membrane exists in nature itself, but it was not until 1748 that nollet found that water could naturally diffuse into the pig bladder containing alcohol solution that humans found the phenomenon of infiltration.

In the natural permeation process, the solvent diffuses from low concentration to high concentration through the permeation membrane; Reverse osmosis means that under the action of external pressure, the solvent in the concentrated solution diffuses through the membrane to the dilute solution. The semi permeable membrane with this function is called reverse osmosis membrane, also known as RO membrane.

The key of reverse osmosis technology is the middle layer of film. In normal filtration procedures, various impurities in water, such as bacteria, viruses and sediments, cannot pass through the filter element. However, trace heavy metal ions that may be contained in the water, such as arsenic, zinc, nickel, cadmium, chromium, copper, lead, etc., may drill through the gap of the filter element. When drinking water is purified, the pores of reverse osmosis membrane can be smaller than water molecules, so how did water molecules pass?

Have you heard of clavicle skill???

ha-ha!!

Of course it's not bone shrinking skill. The soul is light~~

But because - booster pump!!

The purpose of booster pump is to increase the water pressure to about 70psi. Through high pressure, water molecules move from one side of the membrane to the other, that is, why 0.324nm water molecules can pass through 0.1nm membrane holes, to be exact, squeeze through.

At this time, not to mention heavy metal ions, even light metal ions such as calcium and magnesium, which are smaller than water molecules, can not pass through the film.