Anti-scaling or anti-fouling is used to prevent the formation of salts and water deposits on the membranes. Anti-scalant has a great effect on the lifespan of reverse osmosis membranes and reduces the cost of replacing filters annually.
This chemical is considered as a main and integral component of any industrial water purifier.
Among the materials that deposit on polyamide membranes:
Calcium carbonate (CaCO₃)
Calcium sulfate (CaSO₄)
Barium sulfate (BaSO₄)
Steronium sulfate (SrSO₄)
In order to prevent the deposition of these soluble salts on the membranes, it is injected into the incoming water of the Antiscalant RO system. The amount of antiscalant injection depends on various parameters such as water analysis, flow rate, temperature, pH, system recovery rate, water source, type of membranes and how the membranes are arranged. The rate of antiscalant injection is in the range of 1 to 6 ppm.
Disadvantages of using substandard antiscalants: reduces production capacity, increases the amount of water-soluble salts in the production of TDS production output, increases pressure on class pumps and reduces pump life and increases power consumption due to increased amps, frequent washing Membranes are caused by clogging and ultimately reduce the lifespan of membranes and its early replacement.
Due to the fact that the price of reverse osmosis membranes as the core of the water purifier is very high and if low quality antiscalants are used, the membranes will suffer from many problems, including problems that can significantly reduce the useful life of membranes. Was.
At present, there are different types of anti-scalants with different prices in different countries, the most important of which are Flucon anti-scalant, Genesis anti-scalant, and Avista.
There are different types of anti-scalants:
1- Phosphonate based anti-scalant
The properties of this type of antiscalant are among the best in preventing the formation of scale, but their dispersing properties are very limited.
2 – Polymer-based anti-scalant
There are many benefits to using such anti-scalants:
- Have a high concentration and prevent fouling
- For seawater, salt wells, hard water, water with a hardness below 1000 ppm is generally used and the corrosion rate is very low and non-toxic.
- They do not allow any carbonate or phosphate deposition.
- They perform better due to their high chelating agent power.
- They have a very low corrosion rate (anti-corrosion)
- They are non-toxic and do not cause skin or respiratory problems for humans.
- They have good dispersion performance against carbonate and sulfate deposits.
- Provide the need to wash the membrane over a longer period of time.
- Reduces the risk of algae and biological contaminants.