Avista Advisor

Avista Advisor for Reverse Osmosis Membranes

Avista Advisor is a free software program provided by Avista Technologies at http://www.avistatech.com. This is a quote from Avista’s home page:

“Avista Technologies is devoted exclusively to the supply of specialty chemicals and technical support services for the membrane separation industry, specifically reverse osmosis and nanofiltration. Our products and services are designed to prevent, reduce, or treat the fouling that occurs within these systems.”

Avista’s Advisor software program will help you select from their extensive chemical offering to help you solve problems you might be having with your reverse osmosis (RO) system. The opening screen for the Advisor program is shown below.

Avista opening screen shot

The Advisor program is extremely easy to use. You start off by filling in basic project information as shown in the image below. Enter the plant or project name, identify the SDI (silt density index) range of your RO feed water, set your flow rate which is required for calculating product quantities as you’ll see further down this page, and then pick the number of RO systems you are evaluating.

Now this is the only difficult part of using this software. You must have a detailed water quality analysis to make use of the program. But anyone who works with RO units knows that having this level of water quality information is standard practice. Take a look at the image below to see the key water quality data required for analyzing your water.

In the Avista Advisor screen shot above you are seeing the results of an analysis that was already performed. Note that caustic dosing has been selected and the pH in the feed water has been increased from 8.52 to 9.3. Without the addition of caustic to increase the pH look at the scaling potential of the water as shown by the Advisor graphic below. Aluminum is a major problem for this particular water source. That’s because the city tends to overdose with aluminum sulfate or alum as part of their water treatment process. That aluminum is a major problem for RO membranes. Increasing the pH of the feed water increases the solubility of aluminum which delays its tendency to drop out on the membrane surface.

In the image below the saturation index or scaling potential of the water has been improved dramatically. You can see that with pH adjustment and the addition of a small amount (1 ppm) of antiscalant everything is green indicating good water quality.

The system design for this example called for a product water or permeate flow of 720 gallons per minute (2.73 cubic meters per minute). With an RO system producing this amount of water, with a feed water pH of 8.5 adjusted up to 9.3 and 1 ppm of antiscalant, you can see in the chemical summary graphic below how much chemical is required each month and yearly. This is an excellent, easy-to-use, informative program for those of you with RO system responsibility.