New product: Xylem energy efficient aerobic digester

The solution tries to support more sustainable wastewater treatment operations

 

Aerobic digestion is often the second largest consumer of energy, after biological treatment aeration, at a wastewater treatment plant, according to Xylem field tests. Xylem has launched a new aerobic digester solution under its Sanitaire brand that decreases energy consumption by up to 90 percent, according to the company. Sanitaire Vorelodos aerobic digester aims to meet current and future US Environmental Protection Agency (EPA) effluent and biosolids regulations, while simultaneously reducing operational costs.

The company claims that the significant energy reduction means that in larger plants (larger than 1 million gallons per day depending on prior energy and chemical consumption) the system effectively pays for itself within one year. The solution also lowers chemical use as a result of alkalinity recovery and a reduction in the amount of phosphorus being returned to the main plant. An automated decanting feature and aeration control means that staff time can be invested in other activities.

Results from tests carried out at Green Lake Wastewater Treatment Plant in Wisconsin between January 2016 and March 2017 showed that the Vorelodos aerobic digester reduced nutrients (nitrogen and phosphorous) being recycled back to the main treatment plant by more than 95 percent while simultaneously lowering energy consumption by 95 percent.  

Glen McCarty, Director of Public Works, Green Lake Wastewater Treatment Plant, said, “Permitted levels of nitrogen and phosphorus in effluent water are becoming ever stricter in an effort to protect surface waters from eutrophication. At the same time, plants are required to reduce energy and chemical consumption and are often challenged with limited time and staff. Sanitaire Vorelodos enabled us to do more with less.”