Effects of eukaryotic predation on physical stability of heterotrophic biofilms in membrane-aerated biofilm reactors (MABRs)

摘要

The effect of eukaryotic predation on biofilm detachment in membrane aerated biofilm reactors (MABRs) was investigated. Heterotrophic biofilms were grown under three conditions: (1) baseline conditions with predation, (2) with a predation-inhibitor, and (3) initially with a predation inhibitor, then with no inhibitor and with re-inoculation. Detachment tests were carried out on each biofilm by increasing the fluid shear rates. Relative detachment for the three conditions were 45, 7 and 14 %, respectively. The biofilm viscous and elastic moduli without predation were 1581 and 9800 Pa, respectively. With predation, they were 363 and 1766 Pa, respectively. In conclusion, internal voids induced by predation weakened the biofilm mechanical resistance, increasing the potential for detachment.