Recover, Recycle, Reuse

DFW’s glycol recycling facility is capable of handling 40 million gallons per season.

Glenn Vanderlinden, president of Edgewater Support Services, explains his company got its start in glycol recovery in 1992 when stormwater became a problem at Toronto 's Pearson International Airport .

Explains Vanderlinden, "We, along with other equipment distribution companies, were asked to take a look at supplying them with equipment that might be able to fix the problem. We demonstrated vacuum sweepers, mechanical sweepers, runway sweepers, every sort of thing you can think of. Everything was doing a little bit of the job, but nothing was really fixing the problem. We told Air Canada that if they were interested, we could build them a prototype. About six months later they came back to us after trying a bunch of things and agreed that they wanted to look at the prototype, which we built to collect the material; we call it a RampRanger. We were able to meet the compliance requirements of Environment Canada within less than two months."

The company continued collecting the runoff but was soon faced with the problem of customers having a difficult time in disposing of the material collected, Vanderlinden says. "The waste industry and sanitary sewers were struggling with taking anything with the kind of loading that it had. And basically our customers pressured us to find ways of recycling this material and handling what we were collecting."

THE CHALLENGES

In processing the material, Vanderlinden says the company soon realized the challenges involved. "First of all, the temperature you're operating at, volumes of material, storage requirements, and just trying to figure out what kind of end use we were supposed to process this material to, because there really were no markets to accept it. So we began to clean it and we found more and more efficient ways as we went and got to the point of making a virgin equivalent type of glycol and selling it to third parties. But it was economically marginal to do that, and could only be done if the customers weren't requiring us to deal with large amounts of stormwater."

Some four years ago, Edgewater was able to form a relationship with Octagon Process, one of the largest manufacturers of virgin wing deicer. Vanderlinden explains that Octagon was prepared to remanufacture wing deicer and was looking for a partner.

Together, Edgewater and Octagon Process gained the support of North-west Airlines to collect, process, and recycle the recovered glycol. "This material was in fact as good or better than the quality of the wing deicer being applied to their planes at the time."

STORMWATER IS FOCUS

For Vanderlinden, the primary focus is not the recycling side. As he explains, the recycling provides a cost-effective way of getting rid of the glycols recovered from stormwater.

"At the end of the day, none of these airports would have spent any money trying to contain or collect or retain any of this material if they didn't have a stormwater problem," he says. "They're not doing it because recycling is necessarily a money making, cost-effective thing to do. It is if you can collect the material at high enough concentrations. The thing that makes it worthwhile is if you're sending it to a sanitary sewer, they're going to charge you a disposal fee."

The real focus for Vanderlinden is the treatment of stormwater such as the system installed at Dallas/Fort Worth International Airport.

"We don't just fix the glycol problem, says Vanderlinden. "We're also removing oils and greases, phenols, ammonias, and basically solving their entire stormwater problem."

The system at DFW includes some 40 acres of deicing pads, he says. All the deicing materials are sprayed on those pads. It then runs into pipes and on to a retention pond system, made up of four ponds of three million gallons each, which were constructed by the airport. The fluid that is collected is processed and any large suspended solids are removed. The liquid then goes through a proprietary process called Duraflow, which removes oils and greases while protecting the rest of the membrane system. It then makes its way into Edgewater's Scavenger reverse osmosis treatment system specifically designed to handle the extraction of glycol from stormwater in real-time flows and to take the glycol extracted from the stormwater and direct it to a recycling operation.

The materials collected that cannot be turned around as natural additives are cleaned, contained, and disposed of under the appropriate regulations.

Vanderlinden says the stormwater is processed in flows that are competitive to what a sanitary sewer would be able to accept on a daily basis. At DFW, the glycol is removed from the stormwater to a level in which it's less than 250 parts per million, making the stormwater suitable for the sanitary sewer.

"It's a flow-through process," says Vanderlinden, "and this system, as installed, will handle 40 million gallons per winter season. Right now that's adequate for what they need to collect."

Edgewater manufactures much of the equipment and owns the technology necessary for the recovery and processing of the glycol.

FINANCIAL REWARDS

Airports are saving money in two ways, says Vanderlinden. They are receiving cheaper water treatment and at the same time, the recycling produces a substance that can be reused, reducing the cost of deicing material.

The DFW system took six weeks to install, at a cost of $6 million to the airport. Vanderlinden says the overall project for DFW, including the building that houses the treatment facility and discharge ponds, was near $30 million.

The employee staffing for the collection and recycling facility is provided through another business partnership with ASIG, an aviation services provider.

"We're already doing multiple lines of business at these airports," says Shannon Carney, ASIG area general manager, "in most cases, it's just a matter of adding employees."

ASIG employees are involved from the beginning of the process, according to Carney, and continue on to operate and manage the processing facility for the airport.

Besides DFW, Edgewater has operations at Minneapolis , Providence (RI), and Chicago 's O'Hare and Midway airports. But because each airport has different needs, all the systems are design/build, says Vanderlinden.

For those airports that may not be large enough to justify putting a recycling system in, Edgewater offers offsite disposal alternatives as well.