石油污染土壤修复技术应用现状

石油开采、贮存及运输过程中泄漏事故屡有发生,对受其污染的土壤进行有效治理成为社会关注的焦点。本文介绍了石油污染问题及物理、化学、生物治理方法,着重介绍了微生物修复技术的分类及应用现状,探讨了降解微生物筛选和定植、石油烃生物可利用度改善等制约生物修复效果的关键因素。     

土壤石油污染的生物修复技术

1．土壤石油污染生物修复的基本概念 石油污染的生物修复技术是以自然环境中的土著菌、人为投加的外来菌或基因工程菌为主体，利用微生物的生命代谢作用将石油分解成二氧化碳、水，从而降低或去除污染物的毒性以达到修复环境的目的技术。污染土壤的生物修复技术可分为原位修复技术和异位修复技术。原位修复技术也称为原地修复技术，它是通过在污染地点实施微生物的接种和其他技术措施，在污染地点的自然环境条件下，利用微生物和空气中的氧实现石油分解氧化处理。异位修复技术是通过将污染土壤转移到一个固定的地点，人为地创造有利于微生物生长的环境条件（如温度、湿度、水份、氧气及适宜的培养基等条件），最终实现石油的分解氧化处理。     

应用生物修复技术处理石油污染土壤

对辽河油田石油污染土壤进行微生物修复的可行性进行了试验研究。分离出4种对石油污染物有降解作用的细菌。研究表明：加入适当的N、P元素可加速生物降解;在H2O2和油酸钠的用量分别为8850mg/l和166mg/l时,24天内的生物除油率可达48%;原土壤的pH值对细菌活性的影响不大。     

探讨石油污染土壤的微生物技术研究

随着我们中国社会的不断发展,能源和环境问题成为了我国社会经济发展过程中所面临的突出问题.石油对土壤的污染主要是来源于在石油勘探、开采、运输、储存、加工以及生产过程,而石油开采工作过程中的落地原油受到地球的吸引,在毛细血管力的作用下沿土壤深度方位迁移并出现平面扩散,因此在油井区域的周遭大部分面积的土壤会更容易受到石油的污...     

固定化微生物应用于生物修复石油污染土壤

 从石油污染土样中筛选和纯化了2株降解石油污染物的高效微生物菌株H和F，以它们为生物活性物质，采用生物大分子仿生合成出的纳米多孔SiO₂为载体，通过表面吸附固定化方法将其固定，制备出固定化微生物。将固定化微生物应用于含有石油污染物土壤的生物修复。结果表明，该固定化微生物对石油污染物50h一次降解率高达96.2%；通过8次的反复实验，50h的原油降解效果保持在85%以上。     

固体微生物菌剂在克拉玛依石油污染土壤 生物修复中的应用

分析了克拉玛依石油污染土壤的理化性质,采用固体微生物菌剂对该土壤进行生物修复,考察了最优修复条件及修复过程中土壤微生物数量、酶活性和石油烃组分的变化。结果表明,克拉玛依石油污染土壤是以粉砂为主的灰漠土,含水率低,含油率高,弱碱性,土壤中三大营养元素（氮、磷、钾）的有效含量低,不利于微生物的生长繁殖。最优修复条件为土壤孔隙度55%、含水率25%、固体菌剂添加量5%、氮/磷摩尔比10、生物表面活性剂添加量05%,在此条件下经过60 d的生物修复,含油率由最初的407%下降到181%,降解率为5553%,小于C27的正构烷烃得到了明显的降解,土壤中的微生物数量、酶活性（脱氢酶活性、过氧化氢酶活性和多酚氧化酶活性）均有所提高。在生物修复过程中,单靠改善外在环境条件进行生物刺激,无法有效去除石油烃,添加微生物菌剂进行生物强化是去除土壤中石油类污染物的关键因素。     

稠油污染土壤微生物修复试验研究

辽河油田集输站落地稠油污染1号土壤为松散的硬固体,含油7.4%、含水率17.8%、密度2.64 g/cm³、pH值7.8;稠油污染2号土壤为黏结的软固体,含油21.5%、含水率35.6%、密度2.23 g/cm³、pH值7.8。污染1号土壤的稠油含饱和烃29.11%、芳香烃22.54%、胶质30.26%、沥青质18.08%;污染2号土壤的稠油含饱和烃25.19%、芳香烃26.23%、胶质32.49%、沥青质16.09%。从稠油污染土壤中富集、分离、筛选出1~5号菌株。以稠油为唯一碳源,1~5号菌株对原油的降解率分别为20.0%、6.1%、22.5%、12.7%、34.7%。选择降解率较高的5号菌和对环境适应性良好的1号菌作为优势菌。1号菌的最佳N、P源分别为(NH₄)₂SO₄和K₂HPO₄,降解率分别为28.13%和15.16%;5号菌的最佳N、P源分别为KNO₃和KH₂PO₄,降解率分别为49.12%和50.04%。0.15% H₂O₂具有良好的氧化降解效果和促进作用,但单独使用的降解率为25%（60 d）。添加表面活性剂后,含油土壤60 d内的降解率大幅提高,吐温-80、吐温-40、鼠李糖脂最高降解率分别达73%、70%、84%。选择0.1%吐温-80和0.1%鼠李糖脂复合表面活性剂作为油污土壤微生物降解的渗透剂。通过小型扩大修复实验,经过80 d的修复,1号、2号稠油污染土壤的降解率分别为66.7%和73.5%,降解效果良好。     

石油污染土壤微生物群落分布特征

采用高通量测序法研究东营某炼油厂不同污染程度的土壤中细菌、真菌和古菌的群落结构,分析石油污染对土壤微生物群落结构的影响.结果表明:微生物群落可操作分类单元(OTU)数量随着油污土壤油含量的增加先增多后减少;Beta多样性与土壤石油污染程度有一定的关系;受污染程度相近的土壤样品,微生物群落结构的相似度较高.细菌、真菌、古...     

SDBS残留对微生物修复石油污染土壤的影响

为探究表面活性剂清洗对微生物修复石油污染土壤的影响,模拟实际石油污染土壤微生物修复,考察不同十二烷基苯磺酸钠(SDBS)添加量的土壤修复过程中总石油烃降解率的变化情况,探究了SDBS对微生物修复石油污染土壤效果的影响;比较了不同微生物法修复石油污染土壤的实验方案,确定了最佳微生物修复方式。结果表明：少量的SDBS残留对后续微生物修复有促进作用,但SDBS残留质量分数大于1 mg/g时,则不宜于石油污染土壤的生物修复;土著菌+秸秆固定化微生物和土著菌+游离高效降解菌+秸秆2种修复方式,启动快,降解率的增速大,修复效率高,可以实现石油污染土壤快速和持续修复。     

原油污染土壤生物治理研究初探

治理原油污染土壤的经济，简便方法是就地生物治理法，掌握生物治理方法，进行处理能力测试是有效开展治理工作的前提，通过实验研究确定向油污土壤中添加营养物和原油降解菌能加速原油降解。     

Multi-process Bioremediation as an Improved Approach for Petroleum-contaminated Soil Restoration

A multiprocess bioremediation approach was applied to treat petroleum-contaminated soil from Dagang Oilfield, China. The bioremediation processes involved the use of four exogenous microbial strains and six herbage plants screened from a large number of species to remove low levels of total petroleum hydrocarbons (TPH) in contaminated soil. The experimental results indicated that the reduction of TPH increased with the improved community structure from the exogenous petroleum-degrading bacteria by over 35% as compared with that using the indigenous bacterial community. The refreshed microbial consortium was also able to accelerate the reduction of TPH via plant roots (phytoremediation) by over 47%. The TPH reduction rate diminished over time. Molecular biomarker ratios such as Ph/nC17, Pr/nC18 increased during the experiment but the ratio of Pr/Ph decreased. The results suggested that the multi-process bioremediation may significantly shorten the bioremediation duration and can be quite effective for treatment of soils contaminated by lower levels of petroleum.     

利用本源微生物修复技术处理含油土壤试验研究

利用本源微生物对受石油污染土壤进行了生物修复的室内试验。研究表明,在添加双氧水电子受体和适量的营养盐后,75天内土壤中石油烃的去除率可达到62．5％;添加表面活性剂可以促进微生物对石油烃的生物降解,在添加0．05％（ω）的吐温一40后,75天内土壤中的石油烃去除率可由62．5％提高到了88．6％。试验证明对含油土壤进行生物修复是可行的。     

激活剂对石油污染土壤修复的强化作用及修复条件的优化

在石油污染土壤生物修复实验中,通过添加氮源、葡萄糖、H₂O₂、木屑4种不同作用的激活剂来强化修复,考察了激活剂的强化修复效果以及各激活剂之间的相互关系,并在单因素实验的基础上,选定氮源、H₂O₂和木屑的添加量3个影响显著性因素进行响应面优化实验研究,得到最优实验条件,并建立了土壤石油残留率与各激活剂添加量的二次回归方程。结果表明,石油污染土壤生物修复的最佳实验条件为C/N质量比24.6、H₂O₂的加入量（质量分数）0.32%,木屑加入量2.9%;在此条件下,石油污染土壤强化修复30 d后的石油残留率的理论值达43.6%(以修复前土壤样品的石油烃含量为基准), 验证值为42.4%,两者相差不大,该模型能用于预测和分析添加激活剂强化修复石油污染土壤的情况。     

腐植酸对石油污染土壤特性和生物修复效果的影响

为研究腐植酸对石油污染土壤生物修复的影响,考察了不同腐植酸含量对石油污染土壤特性以及在低含水条件下对石油污染土壤土著微生物修复效果的影响,探究了腐植酸在干旱少降水地区修复石油污染土壤的可行性。结果表明,土壤腐植酸质量分数为100 mg/g时有利于调节土壤的C/N质量比,有利于土著微生物对速效磷的利用,土著微生物酶活性比对照土壤样品有显著提高;在低含水率条件下,腐植酸质量分数为100 mg/g土壤样品的30 d石油烃降解率达到277%,而对照土壤样品只有5.9%。      

Assessment of In Situ Bioremediation of Oil Contaminated Soil and Groundwater in a Petroleum Refinery: A Laboratory Soil Column Study

Precipitation and seasonal water level fluctuations mostly add to the problem of soil and groundwater contamination and lead to pollution of capillary fringe layer and exacerbation of groundwater contamination. At the Tehran Oil Refining Company (TORC), with critical problem of soil and groundwater pollution, finding a suitable remediation method has been a big concern. As bioremediation is one of the most economically and technically attractive decontamination methods, it was chosen for preliminary study to solve this problem. For simulation of the region, soil column treatment method by using oil habituated indigenous microorganisms of the area was selected. The main purpose was assessing the suitability of bioremediation method in the target area for treatment of capillary fringe layer. Two columns (one as treatment column and the other as a control) were designed and the variation of different parameters including dissolved oxygen (DO), pH, the number of viable and active microorganisms (CFU/mL), and biodegradation rate during 30 working days were recorded. The experiments showed that a major part of degrading microorganisms were facultative anaerobic. pH was not an inhibiting factor and the number of active microorganisms was increasing during aeration time. The results of solvent extraction method also revealed that during 30 days, about 6% of total petroleum hydrocarbon in columns was biologically degraded. Finally, it was disclosed that bioremediation method could be effective in solving the area's pollution problem. However, new studies should be conducted to optimize the biodegradation rate and extrapolate from the laboratory scale results to the field ones.     

The Surveying of Soil and Groundwater Pollution in a Petroleum Refinery and the Potential of Bioremediation for Oil Decontamination

Soil contamination with crude oil is an important worldwide issue and the remediation of oil contaminated soils, sediments and groundwater is a major environmental challenge. In the target area of this survey, which is a petroleum refinery near Tehran, soil and groundwater pollution, and its source, contaminated area, and distribution of pollution were studied by means of different measurements. Oil content and volatile organic compounds were measured to determine soil and groundwater contamination. The investigations showed that the contamination of soil which is mainly silt and clay has reached to the groundwater which is around 20 m underground and formed an oily layer mainly containing gasoline, kerosene, and gas oil with different thicknesses in the whole area. The free oil existing over the groundwater table could be removed by physical ways such as pump and treat method but decontamination of soil is more complex. Due to long-lasting contamination of the field, the existence of accumulated indigenous microorganisms and the probable ability of them to effectively biodegrade pollutants by man-assisted interventions are expected. In this survey in order to clarify the contamination problem, some experiments have been done on the region soil and groundwater. Besides, the feasibility assessment of bioremediation in the investigated area is performed.