New frontier of biological wastewater nutrient removal

Monday, October 10, 2011 - 3:00pm
Event Type: 

Gold Room, Hilton Garden Inn, 1325 Dickenson Avenue, Ames

Shihwu Sung, Professor in Environmental Engineering, Department of Civil, Construction and Environmental Engineering

Due to the excess nutrients (phosphorus and nitrogen) discharging from waste streams directly into water bodies without advanced treatment, receiving waters are suffering from eutrophication and hypoxia. The USEPA nutrient pollution control strategy is calling for enforcing nationwide numeric nitrogen and phosphorus discharge criteria. To address the above issue, a new process is proposed to integrate several groups of microorganisms responsible for organic carbon, nitrogen, phosphorus removal i.e. heterotrophs, nitrifiers, anammox (anaerobic ammonium oxidation), and phosphorus accumulating bacteria into a robotic system. The novel system has several advantages over the traditional processes, such as the followings: (i) Less than half of the aeration required (less electricity consumption) and no external carbon sources or chemical addition (economical), (ii) No excessive sludge production: Anammox bacteria grow by using CO2 as the sole carbon source with a very low biomass yield, and (iii) Environmental friendly: very little green house gas (nitrous oxide) emission compared to traditional wastewater nutrient removal.