AWC has developed highly effective inhibitors that eliminate the most challenging scales and significantly reduce colloidal and organic fouling in reverse osmosis (RO) and nanofiltration (NF) membrane systems. All AWC antiscalants are NSF approved for use in potable membrane systems. Our antiscalants are highly effective for all feedwater sources, including groundwater, wastewater, fresh surface water, seawater, and municipal water.
Our high-performance reverse osmosis (RO) antiscalants are effective at remarkably low dosages and can inhibit scales even at very high saturations. The use of AWC antiscalants can eliminate the need for acid dosing, enable plants to operate at higher recoveries, and reduce cleaning frequencies.
AWC RO antiscalants control scales such as calcium carbonate, calcium phosphate, calcium sulfate, barium sulfate, strontium sulfate, calcium fluoride, iron hydroxide, iron phosphate, silica, and colloidal foulants. Our RO antifoulants disperse colloidal silica and natural organic matter.
RO systems use crossflow membrane filtration, where the water that is not purified exits the system as a concentrated brine. As water passes to the permeate side, the unpurified fraction of the water is left with all the salts, organics and colloidal particles that are rejected by the membrane. The higher the operating recovery, the more concentrated the brine will be. When dissolved salts in the brine exceed saturation, they begin to precipitate as scales. Likewise, organics and colloidal particles have a higher fouling potential as they become more concentrated along the length of the membrane system.
What are RO Antiscalants?
RO antiscalants are specialty chemicals that are added upstream of a reverse osmosis membrane system. These scale inhibitor 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.
reverse osmosis chemicals & ro antiscalant
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 chemical 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 reverse osmosis chemicals fed to a water treatment plant.