Wastewater Treatment System May Save Water

North Carolina State University scientists are evaluating a relatively new wastewater treatment system that potentially offers significant water conservation by treating wastewater so that it can be reused.

A pilot-scale IBAC wastewater treatment system was donated to the university by BioDyne, the Raleigh, N.C., company that makes and sells the patented technology, said Dr. Leonard Bull, associate director of the Animal and Poultry Waste Management Center in the College of Agriculture and Life Sciences at NC State.

The system, a silver and blue steel vertical cylinder that is approximately 30 feet tall and 6 feet in diameter, was installed at the university’s Lake Wheeler Road Field Laboratory just south of the Raleigh city limits, where it is being used to treat wastewater from pig barns at the site. IBAC stands for Integrated Bio-Active Clarifier.

“This is a wastewater treatment system that involves a combination of aerobic, anaerobic and anoxic treatment in sequence and interaction,” said Bull. “It can be used to treat and clarify wastewater from a number of municipal and industrial sources.”

Aerobic, anaerobic and anoxic wastewater treatment systems all employ microorganisms to clean wastewater. The terms refer to whether or not the microorganisms exist in an environment with or without oxygen. All three types of wastewater treatment are well known and are often used to treat wastewater.

What makes the IBAC system unusual, Bull said, is that all three types of wastewater treatment plus clarification and sludge treatment are combined in one vessel (the steel cylinder) that is smaller than other treatment vessels.

“This is the smallest footprint we’ve seen for this type of technology,” Bull said.

Bull added that the system will be evaluated for its ability to clean wastewater from buildings that house pigs. Like most pig barns in North Carolina, the buildings at the Lake Wheeler Road site have concrete floors with slotted openings in them. Pig waste falls through the slots to a pit below the floor. The waste is then flushed with water to a nearby lagoon, where it decomposes.

Bull said the IBAC system will be evaluated to see whether it may be possible to clean, then recycle the water used to flush waste from the pig barns. Cleaned wastewater would be pumped back to the barns, where it could again be used to flush the barns.

He added that university officials are interested in the system for possible use with a golf course being built on the university’s Centennial Campus. If the system works well, it could be used to recycle wastewater from Centennial Campus to irrigate the golf course.

Bull said several residential developers are also interested in the system for similar reasons. It could be used to recycle wastewater for irrigation within residential developments.

The IBAC system has been evaluated and tested by various organizations in Canada for more than 10 years. The Lake Wheeler Road system is pilot-scale. It was shipped to North Carolina from Canada, where it had been tested for treating wastewater from a food processing plant, Bull said. He added that wastewater processing systems that employ the IBAC technology are in operation in Saudi Arabia and Canada in municipal and industrial applications.