Cloth Media Filtration, Ultrafiltration And SCADA-Controlled Filtration


Dave Holland, Senior Application Engineer at Aqua-Aerobic Systems, discusses how various filtration technologies in the company’s product portfolio address important current and future needs for end users.

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: You started talking about cloth media filtration. Go a little deeper on that.

Dave: Our cloth media filtration is an optifiber cloth. We have two configurations, both a five-micron and a ten-micron nominal pore size. It's used primarily after a secondary treatment system in order to reduce the solids, from five to ten milligrams per liter solids range to the two to five milligrams per solids range. Along with that, it removes any of the phosphorus or organics that are also in the particulate.

Water Online Radio: Well, that sounds good, but to two radio guys, help us really understand what the unique benefits are to the end user.

Dave: The benefits are three-fold, really. First of all, you have a benefit of effluent quality. Your tertiary filter is going to deliver the effluent quality that you need. On the wastewater side, it's going to be a lower phosphorus level.

We're seeing a lot of the regulations increased to require lower phosphorus levels, so that's a huge thing. Also, just scarcity of water itself is an issue. Our cloth media filter is very efficient.

What I mean by that is it uses less of the product water to backwash the filter than comparable products. Because of that, obviously you use less water. So on the bigger scheme of things, you're able to reuse more of the water, which is the whole intent.

Water Online Radio: Are there other differences? Aqua-Aerobics is not the only organization with the cloth media filtration, and you mentioned the backwash just then. What other differences are there?

Dave: There are some other differences. The main difference is the cloth itself and the way that it's cleaned. The cloth, even laying flat, has about a six millimeter depth.

There's a lot of capacity for solids holding, and that's a big difference, because a lot of our competitors use a micro strainer, which is really a perforated stainless plate, and so there's no depth of solids.

You only accumulate a thin layer of solids on that micro strainer. The more solids you can get on the cloth, the less frequently you have to backwash, the less water used and the more efficient it is.

Water Online Radio: Talk about Aqua's ultra filtration system. What are the benefits and who should actually care about this?

Dave: Our ultra-filtration system is used in both a tertiary application on wastewater, and also on the drinking water side. The largest benefit of the ultra filtration system is the fiber itself.

It's a special construction, like a honeycomb construction, where it's a multi-bore. There are seven lumen that travel the distance of the fiber, so it's like having seven fibers in one. It gives it a superior strength, so much so that we actually offer a five-year no break warranty. If a single fiber breaks, we replace a whole 2,000-fiber module, free of charge, within the first five years of operation.

Water Online Radio: I want to shift gears on you a little bit. Tell us about Intelepro.

Dave: The Intelepro system is a control system similar to SCADA, only it's a next level. In other words, SCADA is used for monitoring the biological or filtration system, where Intelepro goes to the next level and not only monitors it, but actually controls it.

It does process control, and you can set them either active or passive. You can actually set it up so that it automatically adjusts your times, depending on what the control is for your bioreactor. You might adjust the time of the settle step and let it set to settle longer.

It automatically does those. It automatically adjusts the wasting out of a bioreactor, for instance, so that you maintain the solids. It can adjust your filtration times, depending on what influent water quality characteristics you have.

There's a huge flexibility in that, and you can set it to do it passively, where it just tells the operator, “Hey, this is what I think you should do, in order to optimize your system.”

Water Online Radio: Dave, a lot of guys come through this show talking about the value of SCADA, and you're saying this is the next level. Is this the future?

Dave: This is the future. Really, what we're doing actually on the wastewater side, with biological nutrient removal, we don't know anybody that's doing it to this level, where we actually have live nitrate and phosphorus probes in a bioreactor. It uses that information and adjusts the times and the process to get those low levels of nutrients that we're talking about.

It definitely has an effect on the water side of it, too, because the line is getting fuzzier between wastewater and water, with the amount of reuse that we're seeing.

We're going from tertiary filtration on our wastewater into ultrafiltration in RO, and then reusing the water in direct potable reuse. I mean, in the not too distant future, you're going to have the toilet to tap, just because of the water scarcity issue.

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