Waste activated sludge from five wastewater treatment plants across the city arrived daily at the Greenway Wastewater Treatment Plant in London, Ontario.
After it was combined with Greenway’s primary sludge in holding tanks, operators fed 2.5 percent wet sludge at 200 gpm to four 2-meter belt filter presses 325 days a year. “We average 65,000 wet tons annually,” says Randy Bartholomew, supervisor.
Pumps delivered cake at 23 percent solids to a fluidized bed incinerator, but the material was too wet to ensure total combustion without cofiring 41.67 million cubic feet of natural gas per year.
“Our polymer supplier recommended different products
