What are Reverse Osmosis (RO) Antiscalants?

RO Antiscalants are specialty chemicals that are added upstream of a reverse osmosis (RO) membrane system.  These RO chemicals are designed to prevent or slow-down mineral scale formation on the membrane surface.  For this reason, the right antiscalant is critical for the consistent operation of a reverse osmosis system.

Mineral scale is formed when the dissolved minerals in water are allowed to concentrate to beyond their saturation limit, where they will start to come out of solution.  Similar to water spots on a window, the water sprayed on the window appears clear but there are dissolved minerals in each drop.  As that water evaporates the dissolved minerals stay behind and show themselves as a hard water spot.  In a reverse osmosis membrane system, water is forced through the membrane but the dissolved minerals cannot pass through so they stay behind.  Imagine if each of those ‘spots’ stayed and were joined by more spots to form a large area of mineral scale.  The scale on the membrane surface would prevent water from passing through, so it is essential to inhibit scale for RO systems to operate continuously.

Using the wrong antiscalant can allow scaling and subsequent performance loss to occur quickly.  However, by injecting the correct RO antiscalant at the correct dose rate, scaling problems can be eliminated completely.  Modern scale prediction computer models such as Proton® can determine the severity of scaling potential and recommend the optimal antiscalant and dosage.

RO Antiscalants typically require very low dosage rates and can work in conjunction with other chemicals fed upstream.  RO Antiscalants are also generally safe to handle and will meet all of the environmental requirements for RO chemicals fed to a water treatment plant.