Autor(es):
Abreu, A. A.
; Costa, J. C.
; Araya-Kroff, P.
; Ferreira, E. C.
; Alves, M. M.
Data: 2005
Identificador Persistente: http://hdl.handle.net/1822/4566
Origem: RepositóriUM - Universidade do Minho
Descrição
The specific acetoclastic activity (SAA) of anaerobic granular sludge was
recovered in a lab scale EGSB reactor. The inoculum presented a very low
acetoclastic activity (0.81+/-2.48mg COD-CH4/gVSS.day). Ethanol was fed
at a COD concentration of 1.5g/L, as sole organic carbon source to promote
the biogas production through the hydrogenophilic pathway. During the
operation period the specific methanogenic activity (SMA)1 in the presence
of acetate, propionate, butyrate, ethanol and H2/CO2, and the biomass
morphology were quantified. The SAA steadily increased as expected by the
reactor performance, achieving a value of 183+/-13mg COD-CH4/gVSS.day
at day 108. From the SMA results it was suggested that, until day 62, the
initial methane production rate was dominated by the hydrogenotrophic
population and afterwards, the developed acetoclastic activity started to play
a role in the initial methane production from ethanol. Until day 62 the ratio
between the filaments length and aggregates projected area (LfA)2 increased
due to the breakdown of granules inside the reactor, after that decreased and
granules development was simultaneous with the increase of the SAA.
Percentage of aggregates in size range 0.1 to 1mm (equivalent diameter)
increased until day 40 due to granules fragmentation. When the system
achieved a steady state, the aggregates size increased.