Abstract
Biological Treatment of Wastewater Containing Chlorinated Phenols by a Mixed Culture. Lee, Wan-Seok1, Sang-Wook Jung, Chan-Sun Park, Byung-Dae Yoon, Jang-Eok Kim\ and Hee-Mock Oh*. Environmental Bioresources Laboratory, Korea Research Institute of Biosicence and Biotechnology, Taejon, Korea, 1 Department of Agricultural Chemistry, Kyungpool< National University, Taegu, Korea - The biodegradation of chlorinated phenols in an artificial wastewater was investigated using a mixed culture. The mixed culture was composed of 8 microorganisms isolated from the soil contaminated with various chlorinated phenols. Pseudomonas sp. BM as a main constituent of a mixed culture was Gram-negative, catalase- and oxidase-positive, and rod-shaped, and did not grow at 41°C. It degraded 99% of initial 500 mg!1 of pentachlorophenol (PCP) in the minimal salts medium as a sole source of carbon and energy within 3 days. The degradation efficiency of Pseu.domon.as sp. BM was not affected by the other organic carbon and nitrogen compounds. Pseudomonas sp. BM was able to grow in a broad range of pH 5 - 8, and degrade 2,000 mg/1 PCP. In the experiment with an artificial wastewater containing chlorinated phenols, the degradation efficiency of the mixed culture was the range of 73% (2,4-dichlorophenol) -96% (2-chlorophenol) during an incubation of 7 days. In a continuous culture experiment, the degradation efficiency of mixed culture plus activated sludge was about 2 times higher than that of the control containing only activated sludge. These results indicate that it is possible to apply the mixed culture to other wastewaters containing chlorinated phenols. Key words: Biodegradation, chlorinated phenols, pentachlorophenol, Pseudomonas sp. BM
복합미생물제재를 사용하여 인공폐수에서 염소화 페놀화합물의 생물학적 분해를 조사하기 위하여 다양한 염소화 페놀화합물로 오염된 토양에서 8종의 미생물을 분리하였다. 복합미생물제재의 주된 미생물인 Pseudomonas sp. BM은 Gram-negative, catalase- 그리고 oxidase-positive, rod 형이며 $41^{\circ}C$ 이상에서는 성장하지 않았다. Pseudomonas sp. BM은 단일 탄소원으로서의 PCP(pentachlorophenol) 500mg/l의 농도로 첨가된 최소배지에서 배양 3일 후에 99%의 분해효율을 보였다. 복합미생물제재에 여러 가지 종류의 유기탄소 및 질소원을 첨가한 후 PCP의 분해효율을 관찰하였을 때 큰 차이를 나타내지 못하였다. Pseudomonas sp. BM은 pH 5에서 8까지 넓은 적용범위를 가지고 있으나 pH 7에서 가장 좋은 활성을 나타내었다. 종류가 다른 염소화 페놀을 함유한 인공폐수에서 염소화 페놀화합물의 분해시험은 7일간 배양후 최저 분해효율 73%(2,4-DCP)에서 최대 96%(2-CP)까지 비교적 높은 활성을 보였다. 연속배양 실험에서, 활성 슬러지와 복합미생물제재를 첨가한 것의 PCP 분해효율을 비교해 보았을 때 활성 슬러지만을 첨가한 대조구에 비해 복합미생물제재를 첨가하였을 때는 약 2배의 효과를 나타내었다. 이와 같은 결과는 다양한 염소화 페놀이 함유된 폐수에 복합미생물제재의 적용이 가능함을 나타낸다.
