摘要
利用石油污染土壤中筛选出的2株石油降解菌(铜绿假单胞菌和凝结芽孢杆菌)修复油污土壤,采用紫外光谱法和三维荧光光谱法对油污土壤修复过程中的水溶性有机物(DOM)变化进行了半定量分析。结果表明:1)紫外光谱分析中接种外源微生物前后油污土壤DOM的SUVA254值和ABS285值均有不同程度的减少,说明DOM相对分子质量降低,含有的芳香族和不饱和共轭双键结构减少,其芳构化程度降低;2)随着油污土壤生物修复的进行,与未接种石油降解菌的土壤相比,投加降解菌的油污土壤中水溶性有机物芳香族类蛋白质含量呈降低趋势,紫外区类富里酸呈增加趋势。荧光光谱半定量分析结果表明,接种外源微生物可明显减小石油污染土壤中水溶性有机物的芳构化程度。
In this paper, we would like to introduce our research find- ings on the particular characteristic features of the dissolved organic matters in the biodegradation process of oil-contaminated soil. It is for this purpose that we have screened and isolated two oil-degraded strains, Pseudomonas aeruginosa and Bacillus coagulans from the oil- contaminated soil by using enriched cuhure and streak plate method. The two strains were used for biodegrading the oil-contaminated soil. In the process of biodegradation, the organic matters that contaminate the soil were expected to be extracted by shaking the filtration and then identified by using a UV spectrometry and three-dimensional flu- orescent spectrometry. The results of our experiments demonstrate that, （1） The two strains can degrade petroleum hydrocarbon effec- tively. For example, Pseudomonas aeruginosa displayed much higher degrading rate towards the petroleum hydrocarbon than Bacillus coag- ulans. The degradation rates of petroleum hydrocarbon were found to be as high as 35 % - 44 %, if added with the two strains we have i- solated. However, the degradation rate of petroleum hydrocarbon in the controlled soils with no strains inoculated remains as low as 11% . （2） As compared with the control soil, SUVAz54 and ABS285 of UV spectrometry in oil-contaminated soil which were inoculated with oil- degrading strains, prove to be weakened to some extent, and indicate somehow reduced molecular weight and aromatization degree of DOM. （3） It was found that the structural characteristics of the dissolved or- ganic matters were found to have experienced an obvious change in the process of biodegradation. The fluorescence spectra exhibited a noticed reduction in aromatic proteinoid （ Em= 356 nm and Ex = 285 nm; Em = 326 nm and Ex = 290 nm）, and a relative increase in ful- vie acids Em = 370 nm and Ex = 240 nm） in ultraviolet region com- pared with the control soil. Fulvic acids are a kind of dissolved or- ganic matters with small molecular weight, with its molecular struc- ture being relatively simple and aromatization degree being minor. It can affect the activation of the soil elements and migration and trans- fer of organic or inorganic contaminants in the environment. At the same time, fulvie acids can also be found to affect the release of soil nutrient and the plant growth. And, last of all, semiquantitative fluo- rescence spectrometric analysis indicated that the biodegraded oil- contaminated soil via inoculation of the strains is likely to lead to a greater degree of aromatization of DOM in oil-contaminated soil.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2012年第6期27-30,共4页
Journal of Safety and Environment
基金
陕西省自然科学基础研究基金面上项目(2009JM5005)
榆林市科技计划项目(2011-2011150)
关键词
环境科学技术基础学科
石油污染土壤
微生物降解
水溶性有机物
紫外光谱
荧光光谱
basic disciplines of environmental science and technolo- gy
oil-contaminated soil biodegradation
dissolved or- ganic matter
DOM
ultraviolet spectra
fluorescence spectroscopy
