Date of Award

Spring 1-1-2012

Document Type


Degree Name

Master of Science (MS)

First Advisor

JoAnn Silverstein

Second Advisor

Angela Bielefeldt

Third Advisor

Richard Kuchenrither

Fourth Advisor

Jim McQuarrie


Efficient removal of nitrogen from wastewater is a necessity for many treatment facilities due to the use of fertilizers, the growing human population and increasingly stringent nutrient standards for wastewater effluent. Nitrogen entering the wastewater stream is typically in the form of ammonia and organic nitrogen. Biological nitrogen removal (BNR) is the most commonly used method for removing excess ammonia from wastewater. Metro Wastewater Treatment Facility provides wastewater transmission and treatment services to a large portion of metropolitan Denver and surrounding cities. Due to concern over high ammonia loads from centrate causing stress on the main system, a sidestream bioreactor known as CaRRB is currently in place. Despite the consistency of the operational parameters of CaRRB, large fluctuations in the nitrification performance are occurring and affecting the main system, causing unsteady effluent ammonia concentrations. The goal of this project was to identify the causes of the fluctuations by evaluating the basic factors that impact nitrification and assess potential resolutions