| Title |
Removal Characteristics of Total Coliforms in a Rotating Activated Bacillus Contactor Process |
| Authors |
김응호 ( Eung Ho Kim ) ; 조연제 ( Yeon Je Cho ) ; 박성주 ( Seong Joo Park ) ; 신광수 ( Kwang Soo Shin ) ; 임수빈 ( Soo Bin Yim ) ; 박현주 ( Hyun Ju Park ) |
| Keywords |
Rotating Activated Bacillus Contactor; RABC; process; Total coliform; Bacillus sp.; Extracellular polymeric substance; Disinfection unit process |
| Abstract |
This study was performed to examine the disinfection capability of a Rotating Activated Bacillus Contactor (RABC) system, in which the predominant species, Bacillus sp. was expected to have a removal or inactivation effect of total coliforms. In a settling test with mixtures of E. coli and Bacillus sp., a high removal of E. coli was observed at 20~40℃, while insignificant removal at 10℃. In a batch test, a 4.5% addition of Bacillus sp. to activated sludge considerably enhanced the removal effect of total coliforms, indicating Bacillus sp. played an important role in improving the settlability of the sludge and coliforms. In a pilot scale RABC system, the concentration of total colifroms reduced remarkably in the settling tank, suggesting that total coliforms in the RABC process were eliminated through coagulation and precipitation, probably due to extracellular polymeric substance (EPS) of Bacillus sp. The fraction of Bacillus sp. in the total cell count in the RABC process was in the range of 4.5%~6.3%. The majority (75%) of the Bacillus sp. in the RABC process was Bacillus subtilis which is known to enhance coagulation and precipitation by producing EPS. Hence, an adoption of a RABC process might be able to eliminate the disinfection unit process from a wastewater treatment system. |