Waterguide - Reverse osmosis in water treatment
How does the reverse osmosis work?
In order to understand the term reverse osmosis, it helps to consider the principle of osmosis first. Osmosis describes the natural process in which water is separated from a solution by a semipermeable membrane and diffuses through it. The driving force for the flow of water is the osmotic pressure. In this process, water particles flow through the membrane from the area with a lower particle concentration to the area with a higher particle concentration. The result is an equalisation of the concentrations of the water molecules until an equilibrium is reached on both sides.
Where can osmosis be observed in nature?
In nature, the phenomenon of osmosis or osmotic pressure can be observed in many places. The principle can be understood very well in cherries: after a rain they get cracks in their skin and finally burst open. The skin is a semi-permeable membrane through which the rainwater diffuses, fills the inside of the cherry and finally causes it to burst. Also osmosis plays a major role in processes which are largely invisible. Due to osmosis, plants extract moisture from the soil with their root cells.
From osmosis to reverse osmosis
The natural flow of osmosis from low concentration to high concentration is reversible when external pressure is applied to the highly concentrated solution. The filter membrane allows all water molecules in the solution to "pass through" and filters out all impurities. Thereby the process is reversed. This principle, called reverse osmosis, is used in industry for water treatment, for example to convert water into pure water.
How reverse osmosis is technically implemented?
In the industrial application of reverse osmosis, water is run under pressure through a series of pre-filters and membranes. For this purpose, artificially produced, semi-permeable membranes are coiled and inserted into a pressure vessel. Unwanted substances stay behind and pure water is produced. The pure water produced in reverse osmosis facilities is needed in various areas, including medicine or the production of green hydrogen.
Which role does reverse osmosis play at Herco?
Herco recognised the potential of reverse osmosis systems years ago and manufactures individual and standardised reverse osmosis systems for every conceivable application. They offer a large, manufacturer-independent choice of membranes and a wide range of possible combinations with state-of-the-art control technology. They are particularly water and energy efficient and produce water with very low electrical conductivity. The choice of pre-treatment (e.g. filtration, softening or dosing) depends on the available raw water and the required quality of the permeate. Our Herco specialists will be happy to answer further questions about reverse osmosis and advise you in configuring your unit.