| Title |
High - rate anaerobic treatment at low temperature |
| Abstract |
The investigation of the temperature, organic lading and hydraulic loading rates effects on a high-rate anaerobic reactor was the main purpose of this experiment. The high-rate anaerobic reactor was composed of two compartments : upflow anaerobic sludge blanket and downflow anaerobic filter. The efforts of increasing the microbial concentration to overcome the low temperature effects to the microbial metabolisms were the reasons for two compartments of anaerobic reactor. The synthetic feed, containing glucose, beef extract and peptone as the carbon and nitrogen sources was used for influent with nutrients and trace metals. The volumes of the upflow anaerobic sluge blanket and the downflow anaerobic filter compartment were 1.1ℓ and 1.5ℓ, respectively. The SCOD removal efficiencies were above 80% upto 30㎏ COD/㎥/d at 25℃. The hydraulic retention times were reduced from 32 hrs to 4hrs at 10㎏ COD/㎥/d. More than 8 hrs hydraulic retention time, the SCOD removal efficiencies were 90% at 25℃. The SCOD removal efficiencies decreased with temperature drop. The SCOD removal efficiencies were 90%, 81% and 66% at 25℃, 20℃ and 10℃, respectively with about 5㎏ COD/ ㎥/d. volatile acid increased with increasing the organic loading rates and decreasing the temperature. The temperature was more effective than the organic loading rate to volatile acid variation. The clogging of the downflow anaerobic filter was found at high organic loading rate. Anaerobic protozoa was seen throughout the experiment. |