A survey of prefermenter design, operation and performance Australia and Canada

We have compiled recent data from nine full-scale prefermenters in Australi a and Canada. Using this data, we compare their design, operation and perfo rmance. The design parameters of importance are the prefermenter configurat ion, the fraction of total flow that is fed to the prefermenter, the prefer menter volume and the hydraulic and solids residence time (HRT and SRT). Wi th respect to prefermenter performance, we use the rate of volatile fatty a cid (VFA) production to compare prefermenter efficiency. A number of other performance indicators are also used to compare the output of the prefermen ters (for example total mass of VFA produced). All side-stream prefermenter s compared in this study have relatively similar rates of VFA production (t ypically 14 to 28 mg/L/h), which indicates that they all perform with simil ar efficiencies, regardless of their respective type. (C) 1999 IAWQ Publish ed by Elsevier Science Ltd. All rights reserved.