ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Anoxic granulated biomass and its storage

Miloslav Drtil, Lenka Babjakova, Zuzana Imreova, and Ivana Jonatova

Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovakia

E-mail: miloslav.drtil@stuba.sk

Abstract: Laboratory experiments involving shutdown and repeated start-up of a denitrification USB reactor with granulated anoxic biomass were conducted in order to find suitable conditions for a safe storage period of the biomass. Anoxic granulated biomass stored under anaerobic conditions for a half year period at 6°C and for a half month period at 18–20°C retained its activity and granular morphology. Storage of anoxic granules under anaerobic conditions for a half year period at 18–20°C led to the loss of the biomass original activity and a significant portion of the granules disintegrated. Anoxic granulated biomass stored for a one and a half month period under endogenous anoxic conditions at 18–20°C retained its activity and granular morphology. A two month storage under endogenous anoxic conditions at 18–20°C was too long and the shutdown of the reactor had to be followed by repeated anoxic granulation. Minimum loading of the USB reactor with N-NO₃ to maintain endogenous anoxic conditions in the sludge bed was in the range of 0.06–0.1 kg of N-NO₃ per m³ per day. Restart of the USB reactor can be accelerated by an addition of anaerobic granulated biomass.

Keywords: anoxic granulation – denitrification USB reactor – storage of anoxic granulated biomass

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0447-0

Chemical Papers 67 (12) 1577–1584 (2013)