Kinetics and stoichiometry of P-release with different carbon sources in the anaerobic phase of the biological phosphorus removal process in activated sludge wastewater treatment plants
Author
Wilinski, Piotr
Term
10. term
Publication year
2009
Pages
80
Abstract
Forbedret biologisk fosforfjernelse (EBPR) er en metode i spildevandsrensning, hvor bakterier fjerner fosfor. I den første anaerobe (uden ilt) fase skal bakterierne have en passende kulstofkilde—deres “mad”—for at fungere godt. Denne opgave undersøgte, om aminosyrer kan være sådan en kulstofkilde for polyfosfat‑akkumulerende organismer (PAO), sammenlignet med de ofte anvendte flygtige fedtsyrer (VFA). Vi målte, hvor hurtigt og hvor meget fosfor der frigives (kinetik og støkiometri), hvilket pH‑niveau der bedst understøtter bakteriers optag af aminosyrer, og hvordan bakteriesamfundets sammensætning påvirker processen. Aktiveret slam fra tre danske renseanlæg (Aalborg Vest, Hjørring og Bjerringbro) blev testet i batchforsøg i laboratoriet. Resultaterne viser, at flere aminosyrer kan fungere som kulstofkilde i den anaerobe fase af EBPR, men ikke alle er lige effektive. Blandt 20 afprøvede aminosyrer havde glycin størst effekt. Det mest egnede pH‑interval for fosforfrigivelse med aminosyrer som kulstofkilde var 7–8. Vi observerede også betydelig variation, som hang sammen med forskelle i mikrobielle samfund og med årstiden.
Enhanced biological phosphorus removal (EBPR) is a wastewater treatment method where bacteria remove phosphorus. In the first anaerobic (no oxygen) step, the bacteria need an appropriate carbon source—their “food”—to work well. This thesis examined whether amino acids can serve as that carbon source for polyphosphate‑accumulating organisms (PAO), compared with the commonly used volatile fatty acids (VFAs). We measured how fast and how much phosphorus is released (kinetics and stoichiometry), which pH supports bacterial uptake of amino acids, and how the makeup of the bacterial community affects the process. Activated sludge from three Danish wastewater treatment plants (Aalborg West, Hjørring, and Bjerringbro) was tested in batch laboratory experiments. The results show that several amino acids can support phosphorus release in the anaerobic phase of EBPR, though not all amino acids are effective. Of the 20 amino acids tested, glycine had the strongest effect. The most suitable pH for amino‑acid‑driven phosphorus release was 7–8. We also observed considerable variation linked to differences in microbial communities and to the time of year.
[This abstract was generated with the help of AI]
Keywords
Documents