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Author      Title/Abstract      

Improving Nitrification through Bioaugmentation
Author: Denny S. Parker, Jiri Wanner (Prague Institute of Technology)
Date: 3/107
WEF/IWA Nutrient Removal Specialty Conference, Baltimore, Marcy 2007

The high costs of upgrading treatment plants for either nitrification or nutrient removal has spurred many investigators to examine bioaugmentation as a means to increase nitrification rates and thereby reduce the costs (and space requirements) for nitrification. In the case of biological nutrient removal (BNR) plants, this would allow release of reactor space to accommodate either nitrogen removal or phosphorus removal or both. In this paper, two types of bioaugmentation schemes are reviewed, external and in situ. Both types apply to activated sludge systems, while only in situ schemes apply to fixed film systems. The advantage of external bioaugmentation schemes is that the promotion of nitrification within the mainstream process can be decoupled from its aerobic SRT. The advantage of in situ schemes is that there is less concern about the loss of activity of the seed nitrifiers when transferred to the mainstream process, because their conditions of growth are similar to those prevalent in the mainstream process. The literature is reviewed on all process types, and new information is provided on the Bioaugmentation R (BAR) process which has seen the broadest full-scale applications of any bioaugmentation scheme. The various forms of bioaugmentation are compared and contrasted and the practical limitations in their implementation are reviewed.