黄土地区石油污染土壤生物修复的强化技术初探

Enhanced Technology of Oil-contaminated Soil Bioremediation in the Loess Area

以石油为典型污染物，在本次试验前期工作筛选保藏的众多优势石油降解细菌中选择4株降解能力突出的菌，对该4菌株（分别编号为A、B、C、D）进行随机混合构建优势降解菌群。结果表明：菌群A—C—D降解石油能力最强，3d内原油的降解率达到了39．67％，比单菌除油率提高了13．21％；对该菌群的最佳投加配比进行确定，菌群的最佳接种配比为A：C：D=1：2：0．5，3d内菌群A—C—D在不同接种配比情况下降解率变化范围为27．8％～44．2％，最高值与最低值相差16．4％，因此菌群间各菌必须维持在一定的数量配比的情况下才能达到理想的降解效果。对影响生物修复效果的环境因素，如营养物质（C、N、P）、表面活性剂、通氧量、电子受体等进行综合考虑，通过正交试验确定菌群A—C—D的最佳修复条件为：营养物质配比C：N：P为75：8：3，表面活性剂为0．5％，通气条件为六层纱布，电子受体H2O2的加入量为1．5％。在最佳修复条件下，3d内原油的降解率达到61．46％，比自然条件修复下的除油率4．7％提高了56．76％，较只进行菌种强化时的最高除油率44．2％提高了约17％。

Taking the crude oil as the typical pollutant, this paper obtains four high-effect oil-degrading bacteria which are selected from the many oil-degrading bacteria which have been screened and preserved by our previous experiments, then carries out a random mixing on these four bacteria（coded as A, B, C and D） to build a predominant bacterial consortium to degrade crude oil. The results show that the ability to degrade petroleum of community A-C-D is the best, and the degeneration rate is up to 39.67% in three days, with a increase of 13.21% compared with that of the single fungus; and the best inoculation ratio of community A-C-D is 1：2： 0. 5 with degradation rate of 27.8% to 44.2% in different vaccination proportions in three days. Finally, considering synthetically the concentration of nitrogen and phosphorus, minute ventilation volume, electron aceeptor and so on, which are environmental influence factors of bioremediation, a orthogonal test is carried out to identify the optimum condition for bioremediation of community A-C-D, as C： N： P is 75： 8： 3, the contents of surfaetant and H2O2 is 0. 5% and 1.5% , respectively, and six gauzes for ventilation. Under this condition, the degradation rate of crude oil reaches to 61.46% in three days, with an increase of 56.76% compared with that of natural conditions（4.7% ）, and with an increase of about 17% compared with that of community A-C-D in the best inoculation ratio（44.2% ）.