Control of start-up and operation of anaerobic biofilm reactors: an overview of 15 years of research.

Anaerobic biofilm reactors have to be operated in a way that optimizes on one hand the start-up period by a quick growth of an active biofilm, on the other hand the regular operation by an active control of the biofilm to avoid diffusion limitations and clogging. This article is an overview of the research carried out at INRA-LBE for the last 15 years. The start-up of anaerobic biofilm reactors may be considerably shortened by applying a short inoculation period (i.

Competition between planktonic and fixed microorganisms during the start-up of methanogenic biofilm reactors.

The influence of the hydraulic retention time (HRT) on the start-up phase of a methanogenic inverse turbulent bed bioreactor was investigated. Two identical reactors were monitored, the only differing parameter being the HRT: one of the reactors was fed with a diluted wastewater at a constant HRT of 1 day, the organic loading rate (OLR) being increased by decreasing the substrate dilution; the second reactor was fed at a constant influent concentration of 20 g COD L(-1), the OLR being increased by decreasing the HRT from 40 days to 1 day. After 45 days of start-up, both reactors were operated at an OLR of 20 g COD L(-1)d(-1) and a HRT of 1 day.

Influence of hydrodynamic conditions on the start-up of methanogenic inverse turbulent bed reactors.

The influence of hydrodynamic conditions on the start-up phase of an inverse turbulent bed bioreactor was investigated. Two identical reactors, differing only by the gas velocity ensuring the carrier fluidization and generating the main hydrodynamic strengths (attrition), were monitored. Regarding the first 96 days, the experiments showed better performances for the reactor having the lowest hydrodynamic strengths.