The Pros And Cons Of Ion Exchange Versus Membrane Technology

Frank Caligiuri, Sales Manager for Hungerford & Terry, discusses the merits of ion exchange versus membrane technology with a focus on the constituents being removed

The following is an excerpt from a Q&A with Water Online Radio. Click on the Radio Player above to hear the full interview.

Water Online Radio: H &T has certainly introduced its fair share of innovations into the market over the last decade. Tell us about some of those.

Frank: Hungerford & Terry has been around for 104 years, and I think the industry respects Hungerford & Terry as a think tank of the water treatment industry, because we are an engineering-driven type manufacturing company.

We do respond to the marketplace and we see some changes in water treatment, where there's a focus on high efficiency, and very low waste volumes.

Over the last ten years, we've introduced some flow regenerated ion exchange systems, which of course provide for the bottommost part of our resin bed to be the most fully-regenerated portion of a resin bed and therefore the subsequent operation of the system provides for very, very low leakage and very, very high efficiency.

More recently, we’ve introduced the use of pack bids, which is actually an older technology that's been reintroduced. Pack bid technology, of course, is highly efficient with respect to generating waste volumes.

We've incorporated that mostly in the nitrate removal market, which is a market that has been emerging for the last twenty years since I've been with Hungerford & Terry.

Water Online Radio: Frank, I know there's not a simple answer to this question, but talk a little bit about the pros and cons of ion exchange versus membrane technology and maybe applications that lend themselves more to one or the other?

Frank: Membrane technology, of course, is the latest and greatest technology, and it's a cure-all, because it doesn't require regeneration.

Of course, membranes work with high pressure and they generate a significant amount of waste, oftentimes 25 percent of the waste stream, which is a benefit to some degree, if you're trying to remove every constituent that's in water.

But when you're focusing on certain select constituents like nitrates or perchlorate or hardness or any of the common constituents that are found in municipal drinking water or municipal potable water treatment, more often than not, it's unnecessary to remove all the constituents, just certain select constituents, and that can be done more efficiently with ion exchange.

Again, the pros and cons are, I guess, in the industrial market and the power generation market, where ultra pure water is necessary for boiler feeds, certainly membrane technology offers some significant advantages.

When you talk about municipal water treatment, I think membrane technology in its current state may not offer any advantages, and perhaps some disadvantages in that particular application as well.

We've always been focused specifically on what the application is and what it requires, and the limitations of a particular application before we make a recommendation or a selection.

We have the opportunity to take a look at each application individually…

Click on the Radio Player above to hear the full interview.