bioaugmentation, biofilm, biosolids, capacity, efficiency, nutrient removal
The City of Lakeland, Florida selected bioaugmentation in 2001 to treat odor and corrosion in a partial section of the collection system. The technology was in place within the sewer system for approximately six months on a limited scale and successfully controlled the odors, which challenged the City for many years. The City elected to expand the program to other select sewer areas. Over three years, bioaugmentation expanded to cover the entire sewer system, which is an area of about 100 square miles. The wastewater treatment plant consists of three parallel trains of a 5-Stage Bardenpho process designed for 40,500 lbs/day of influent BOD. Prior to bioaugmentation, the city operated all three trains and processed approximately 30,000 lbs/day of influent BOD. In 2004, the plant turned off one train as a result of additional organic capacity and operated only two trains for 5 years; however, the loading into the sewer system grew more than 30%. With additional biological capacity and operational flexibility from external bioaugmentation, the plant is capable of processing shock loads from a single industrial contributor that discharges 40% of the influent load while staying well below permit limits. This paper compares plant performance using operating data from 2009 after the technology was in place continuously for nine years to 2000 prior to the start of bioaugmentation. The evaluation of plant influent conditions and performance operating three trains in 2000 versus two trains in 2009 is examined in detail using an independent statistician. The approach focuses on the following areas of impact: load reduction, plant capacity, nutrient removal, and sludge reduction.