| Title |
Operational Characteristics of the UASB Pilot Plant at Low Temperatures |
| Authors |
박철휘 ; 정태학 ( Chul Hwi Park ; Tai Hak Chung ) |
| Abstract |
Operational characteristics of the UASB Process were studied using a l㎥ pilot plant treating wastewater from a starch manufacturing industry. The reactor was operated with a HRT of 8 hours and the temperature was maintained at 35, 30, 25, and 20℃ for a significant period. COD loading rate varied from 7 to 14㎏/㎥-day as a result of fluctuating influent COD concentration. Both COD removal and the gas production decreased gradually as the temperature decreased. However, reduction of the treatment efficiency at low temperatures was not severe at all. Gas production decreased from 0.256㎥ per ㎏ COD removed to 0.191 as the temperature droped from 35℃ to 20℃. VS reduction efficiency also decreased gradually as the temperature decreased. Although slight increase of the volatile fatty acid was observed at low temperatures, stability of operation based upon pH, alkalinity and volatile fatty acid was maintained at all temperatures. It is believed that stable operation at low temperatures is possible due mainly to accumulation of active sludge granules in the reactor. The sludge granules, 0.7 to 1.2㎜ in size, were mostly composed of rod shaped and filamentous microorganisms with a number of pores. |