ANAEROBIC DIGESTION OF CATTLE DUNG

IN BIOPROCESS SYSTEM WITH FIXED FILM

E. Choruкоva1, V. Mamatarkova2, I. Simenonov1, L. Nikolov2

1Institute of Microbiology ”St. Angeloff” – BAS

2Biological faculty of Sofia University “St. Kl. Ohridski”

Abstract: Biogas production from cattle dung in a new biofilm reactor has been realized in laboratory living model. As carrier has been used inert plastic mesh supported by sheets of material, resistant to aggression of the liquid media and microorganisms. The carrier and the support have been assembled together to a packed bed forming the biofilm reaction zone. There the biogas has been produced by means of anaerobic microbial society, spontaneously formed self organized biofilm system on the packed bed-carrier. The created biofilm reactor can be related to the class of the submerged packed bed with internal loop, ensured a suitable circulation rate by a special mixing device and appropriate distribution system. The high degree of airproof has been provided by magnetic set-up coupling indirectly the bioreactor stirrer with the electromotor and in such away avoiding the probability of oxygen penetration into the reaction zone.

The comparative studies with a well known bioreactor with suspended culture for biogas production have shown that the new submerged packed bed biofilm reactor has been with two to three times higher intensity. The biofilm reactor created is applicable to function under different conditions – in continuous as well as in batch or in fed-batch regimes. It has been found that the new biofilm reactor can serve also as laboratory tool for biokinetics investigations with real substrates as well as for investigation on the biofilm formation and functioning during long periods allowing observation of the biofilm behavior during the consecutive phase of its living cycle.

Acknowledgments:

This work is supported by the Ministry of Education and Science, NSF, Bulgaria, Contract DO 02-190/08. The support of E. Chorukova by BG051PO001-3.3.04/32 HR Project should also be acknowledged.