Green Firm Finds Goodness in 'Goo'

Green Firm Finds Goodness in 'Goo'

ENN) – Few people get a thrill out of sludge — the goo that remains after cleaning sewage and other wastewater.

But a new technique pioneered by a Bradenton, Fla., company may pump up that excitement level, offering to slice the money Manatee County spends on the residue while providing a safer product.

"Let's face it," said Ken Brown, special projects director for Global Resource Recovery Organization, "we get more and more people coming to Florida, and what's the one thing we never run out of?

"We have to find better ways to deal with it."

Couple together stricter regulation of treated sewage sludge with a population boom predicted by many experts, and dealing with the residual moves up on the priority list. GRRO leaders think they have an answer, and they want to prove it to county officials by mid-January.

Brown said the company, given the go-ahead by county commissioners, would absorb the costs to build and operate a mobile, small-scale unit to dry sludge rolling out of the county's wastewater treatment plants.

All to prove the unit's efficiency vs. the county's current technique.

The county now "presses" water out of treated sewage slurry, said David Shulmister, wastewater division manager. That method leaves behind sludge the consistency of gelatin, containing as much as 85 percent water.

And records show the county spends about $300,000 a year to truck out for application as a fertilizer some 40,000 cubic yards of that liquid-laden sludge — the equivalent of about 1,000 dump trucks.

But, Brown said, "when you truck it, you're trucking mostly water, which is very heavy.
"If you remove the water and then have to dispose of the residue in the same manner, well, you're now disposing of one truckload instead of five."

Cut that water content, Brown said, by adding a dryer, most of which burn a fuel to super-heat air, then expose the sludge to the hot air.

In contrast, he said, the company's drying method blows air past the sludge at super speeds while increasing the pressure. The high-velocity air pulls moisture from the sludge while the climbing pressure boosts the temperature to wick away still more water.

The higher temperature also helps kill bacteria in the sludge, a point not lost on regulators.

A recent study by the U.S. Environmental Protection Agency indicated that "pressed" sludge might contain disease-causing organisms, like bacteria. And county officials promise to scrutinize any plan to apply even treated, dried sludge on local lands.

"We certainly would test any sludge," said Greg Blanchard, an environmental manager with the county, "particularly if it was going to be used for spread within Manatee County."

That, though, is putting the horse before the cart.

First, Shulmister said, the county would have to test the GRRO dryer. Then, officials would have to decide whether the technique merits plunking down the million dollars or so likely needed to buy one, or opt for another drying technique.

"We want to get into the drying technology," he said. "We just don't know which way to go yet. GRRO has a little different technology, but whether it will work or not, I don't know."

Brown downplays the doubt, noting that any business decision comes with a dose of skepticism. County officials, he said, don't have to buy the machine if it doesn't work.

He just wants them to look.

"Sometimes," Brown said, "people look in the wrong places for the right solutions."

Story by Kevin Horan, The Bradenton Herald, Fla. Copyright 2000, The Bradenton Herald, Fla. Distributed by Knight Ridder/Tribune. All Rights Reserved.