Diffusivity of oxygen in aerobic granules
Date Issued
2006
Date
2006
Author(s)
Chiou, Ren-Chao
DOI
en-US
Abstract
The dissolved oxygen (DO) concentration in aerobic granules were measured using microelectrodes, based on which the diffusivity of oxygen was thereby estimated. Considering granules of low bioactivity, the acetate-fed granules of size 1.28-2.50 mm exhibited diffusivity of 1.24-2.28 x10-9 m2 s-1; while phenol-fed granules of size 0.42-0.78 mm had diffusivities of 2.50-7.65 x10-10 m2 s-1.
Based on confocal laser scanning microscope testing the interior of granules exhibited layered structure. The steady-state DO concentrations of phenol-fed granule were recorded, showing that oxygen had been depleted in the surface reacting layer of granule. The oxygen diffusivity inside this reacting layer was estimated 1.34-1.82x10-9 m2 s-1 by assuming an mean oxygen concentration. Considering both steady-state and transient DO responses, the acetate-fed granule had diffusivity of oxygen of 0.6-1.3x10-9 m2s-1, while the phenol-fed granules had diffusivity of 2.5-4.6x10-10m2s-1. Both reaction and diffusion limits the oxygen transport in aerobic granules.
Subjects
生物顆粒
granule
Type
thesis