Anaerobic Thermophilic Colonization of Porous Support

M. Pérez, L. I. Romero, R. Rodríguez-Cano and D. Sales

Abstract
Biofilm development in an open-pore sintered glass material (SIRAN) was studied using a laboratory-scale anaerobic fixed-film bioreactor under thermophilic conditions. The startup and performance of that bioreactor, operating on distillery waste water feed (vinasses), were also studied. Results obtained indicated that stepped organic loading during initial bioreactor start-up reduced the periods of adaptation in the colonization process and micro-organism attachment and biofilm formation was accelerated by the surface characteristics of the carrier. The results obtained by operating with stepped organic loading (Γ = 2.0 kg m–3 d–1 COD) over a period of 70 days suggest that a stable operation of the process (90 % COD removal) and high density of biomass immobilized on the support (20 kgVSatt per m3 SIRAN) is achieved. Epifluorescence microscopy demonstrated that, initially, attached growth was developed in crevices, where biomass was protected from shear forces and, finally, SIRAN was completely covered and biofilm developed on the entire SIRAN particles.

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Keywords
anaerobic digestion, biofilm, immobilization, open-pore sintered glass, support materials, SEM