Abstract
The effects of fixed-bed packed with rock wool on anaerobic fermentation using a synthetic wastewater containing acetic acid was investigated by comparing with the continuously stirred tank reactor (CSTR) operated at 35°C. The following results were obtained:
1. The substrate removal ratio in the fixed-bed fermentor were always higher than those of CSTR under the same conditions. MLVSS and the rate of produced methane gas in the fixed-bed fermentor at the dilution rate between 0.2 and 2 (1/day) were always higher than those of CSTR on the 0.2 (1/day) of dilution rate.
2. The bacteria living in the zone of the fixed-bed were attached to the rock wool and trapped between the rock wool. The density of the latter being about four times as much as that of the former.
3. The rock wool as fixed-bed increased the buffer ability for pH in the liquid of the fixed-bed fermentor.
4. A 32% (v/v) of rock wool as the fixed-bed could make operation conditions suitable for methanogens and might improve the performance of anaerobic wastewater treatment process.
