Comparison of Performance and Operation of Side‐By‐Side Integrated Fixed‐Film and Conventional Activated Sludge Processes at Demonstration Scale

Abstract

A full-scale demonstration of an integrated fixed-film activated sludge (IFFAS) process with floating carriers has been conducted in Ontario, Canada, since August 2003. In this study, data collected on-site from July 2005 to December 2006 are analyzed and compared with the performance of a conventional activated sludge train operated in parallel. Both trains received similar loadings and maintained comparable mixed liquor concentrations; however, the IFFAS had 50% more biomass when the attached growth was considered.In the winter, the conventional train operated at the critical solids retention time (SRT) and had fluctuating partial nitrification. The IFFAS nitrified more consistently and had a doubled average capacity. In the summer, the suspended SRT was less limiting, and the benefit of IFFAS for nitrification was marginal.The lessons learned from the operational requirements and challenges of the IFFAS process (air flow, carrier management, and seasonal foaming) are discussed, and design recommendations are proposed for whole plant retrofit. Water Environ. Res., 81, 219 (2009).

Relationships Between Operational Conditions and Nitrogen Removal and Media Biofilm Accumulation in an IFAS Process Demonstration Study

“…The plant has shown capabilities of N and P removal (Rutt et al 2006). In Ontario, Canada, the Lakeview Wastewater Treatment Plant has been operating as a full-scale IFAS demonstration project (Stricker et al 2009, Maas et al 2008, Ross et al 2004 since August 2003.…”

“…The calculated nitrification rates allow and indirect evaluation of nitrifying activity and an opportunity to evaluate the representation of nitrifying capacity than the effluent nitrogen concentrations; and percentage nitrification. However, only when the effluent ammonia concentration is greater than 1 mg/L the nitrification rates represent the actual nitrification capacity otherwise nitrification is ammonia limited (Stricker et al 2009). Nitrification rate measured as ammonia removal is intrinsically low as it does not take into account the simultaneous hydrolysis of organic-N to ammonia.…”

Application of cigarette filter rods as biofilm carrier in an integrated fixed-film activated sludge reactor

“…The combination of suspended and attached growth biomass increases the carbonaceous removal in terms of the organic loading rate (OLR), measured in terms of chemical oxygen demand (COD), and promotes more advanced wastewater treatment by the longer SRT (Strieker et al 2009). Furthermore, biofilm treatment processes are stable and resistant to organic and hydraulic shock loadings.…”

Comparison of Oxygen Transfer and Uptake Between an Integrated Fixed-Film Activated Sludge (IFAS) Process and a Conventional Activated Sludge Process (ASP)

“…Enhanced nitrogen removal was accomplished up to full-scale (Randall et al, 1996) and enhanced phosphorous removal was accomplished up to pilot-scale (Sriwiriyarat et al, 2005). Besides improving the level of treatment in the ASP, additional advantages have been reported in IFAS processes including greater process stability (Sriwiriyarat et al, 2008), reduced sludge production and reduced solids loadings on the secondary clarifiers (Stricker et al, 2009), and enhanced sludge settleability (Kim, 2010).…”