Abstract
Integrated fixed-film activated sludge (IFAS) that combines the activated sludge (suspended flocs) and attached biofilm has been applied in municipal wastewater treatment to promote nitrification. This study investigated the changes in reactor performance and bacterial community structure in response to different organic loadings (500, 250, 150 mg/L COD) in an integrated fixed-film activated sludge (IFAS) reactor operated under sequencing batch mode. Changes of bacterial population in the suspended flocs and attached biofilm were compared. Biomass in the suspended flocs and in biofilm decreased as the organic loading decreased. The specific nitrification rate was highest when COD was only 150 mg/L in the feeding, which highlighted the effects of competition between heterotrophic bacteria and autotrophic bacteria over oxygen and space. Besides, lack of carbon sources limited denitrification activities. The percentages of nitrifying related genes over total genes were higher in biofilms as compared to those in activated sludge flocs, indicating biofilm was a more favorable habitat for nitrifiers. In addition, extracellular polymeric substance (EPS) in biofilm and suspended flocs changed differently in response to the organic loading changes, which might also be related to the microbial population changes.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Biodeterioration & Biodegradation
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
