천연분말상 유흡착제가 유류분해에 미치는 영향

Abstract

The accidental oil spills in the world have been gradually increasing due to a strong demand for energy and resources consumption caused by rapid industrialization and population growth. These oil spills resulted in harmful effects on the marine ecosystems throughout the world. Physical and chemical oil clean-up technologies such as oil skimmer, herders, dispersants, and oil absorbents have been typically used to prevent an expansion and contamination of the spilled oil. These technologies, however, have some limitations in extensive applications because of geographical limitation and secondary pollution. The objective of this study was to develop a powdered natural oil absorbent carrying PAH degrading bacteria which may have a less environmental impact. The PAH degrading bacteria used in this study were the specific oil degrading species, Sphingomonas sp. KH3-2, Yarrowia lipolytica 180, and Corynebacterium IC 10. The control experiments was also performed utilizing commercial oil degrading agents A and B of "V" company and putative indigenous bacteria in the seawater. To investigate the effect of the powdered natural oil absorbent made of dried pine needles on the oil biodegradation, several batch assays were conducted in Erlenmeyer flasks containing the powdered natural oil absorbent (4.3g) supplemented with Sphingomonas sp. KH3-2, and oil (0.15%, v/v) in 100ml MSM under a shaking condition. The extent of oil biodegradation was determined by measuring the growth of Sphingomonas sp. KH3-2 and the amount of TPH (total petroleum hydrocarbon) removed. In addition putative natural oil degrading bacteria in the seawater were examined in the same manner compared with Sphingomonas sp. KH3-2. The oil degrading potential of the three different bacterial species were tested on Petri dish in the presence of the powdered natural oil absorbent (10g) and oil (10g). The extent of oil degradation was evaluated by measuring the weight removal of oil on a daily basis. Besides, commercial oil degrading agents, A and B of "V" company, were inoculated into the powered natural oil absorbent at 5 different concentrations [0(v/v)%, 25%, 50%, 75%, and 100%]. Here 75% addition of agent A or B was the most effective in the oil removal. However, most of the removal appeared to be caused by volatilization of the oil because of the obvious oil removal at control was also observed. In the experiment employing the three PAH-degrading bacteria, the similar oil removal patterns. In the experiment employing the microbial agents, the oil removal effects seemed to depend upon amount of the powered natural oil absorbent added. It was plausible that this resulted from an enhanced aeration in the bulk matrix formed by the powdered natural oil absorbent added. It might be possible to stimulate biodegradation activity of the oil degraders when their nutrient requirements and other growth conditions were met.