石油污染土壤的生物修复技术研究

通过实验室选择性富集培养，从大庆石油污染土壤中获得了能以大庆原油为碳源快速生长的石油降解菌。采用该降解菌对原油污染土壤进行了原位生物联合修复实验。接入降解菌的处理单元分别种植大豆、碱草或加入蓬松剂，与空白试样作对比。各处理单元石油污染土壤中石油烃含量初始值为2228．25mg／kg（以1kg干土计）。经过135d的生物联合修复，石油烃降解率达63．65％-83．26％。     

共基质和无机盐对原油降解菌株降解原油效果的影响

从大港油田石油污染土壤中分离筛选出1株原油降解菌X3，对原油的降解率达72．6％，经鉴定X3菌株属于假单胞菌属（Psedomonas）。利用生物摇床对X3菌株降解原油的实验发现，共代谢基质α-乳糖对X3菌株降解原油有促进作用，可使原油降解率提高到80．3％；而葡萄糖和蔗糖对X3菌株降解原油有抑制作用。Fe2＋对X3菌株的降解原油也有促进作用，在α-乳糖和Fe2＋的共同作用下，X3菌株对原油的降解率可达82．3％；K＋和Mg2＋对X3菌株降解原油则有抑制作用。在FeSO4质量浓度为0．2～0．3mg／L时，X3菌株对原油的降解率最高，FeSO4质量浓度继续增加，X3菌株对原油的降解率下降。     

Fenton氧化—微生物法降解土壤中石油烃

以长期被苯系物污染的活性污泥为菌源,采用液相"诱导物-中间产物-目标污染物"驯化模式驯化出专性混合石油降解菌群,并将其用于Fenton氧化—微生物法处理模拟石油污染土壤。高通量测序结果表明,产黄杆菌属(Rhodanobacter)、分支杆菌属(Mycobacterium)和根瘤菌属(Rhizobiales)为主导菌属。实验结果表明:接种混合菌群后降解50 d,土样的总石油烃(TPH)去除率较土著菌提高了13.4~20.5百分点;对于TPH含量(w)分别为4%,8%,11%的土样,Fenton氧化的最佳H_2O_2加入量分别为3,4,4 mol/L(Fe~(2+)加入量0.04 mol/L),TPH总去除率分别可达88.8%,65.0%,47.7%,较单独Fenton氧化或单独微生物法均有很大程度的提高,且缩短了降解时间,增加了土壤有机质。     

Fenton氧化—微生物法降解土壤中石油烃

以长期被苯系物污染的活性污泥为菌源,采用液相“诱导物-中间产物-目标污染物”驯化模式驯化出专性混合石油降解菌群,并将其用于Fenton氧化—微生物法处理模拟石油污染土壤。高通量测序结果表明,产黄杆菌属（Rhodanobacter）、分支杆菌属（Mycobacterium）和根瘤菌属（Rhizobiales）为主导菌属。实验结果表明：接种混合菌群后降解50 d,土样的总石油烃（TPH）去除率较土著菌提高了13.4~20.5百分点;对于TPH含量（w）分别为4%,8%,11%的土样,Fenton氧化的最佳H₂O₂加入量分别为3,4,4 mol/L（Fe²⁺加入量0.04 mol/L）,TPH总去除率分别可达88.8%,65.0%,47.7%,较单独Fenton氧化或单独微生物法均有很大程度的提高,且缩短了降解时间,增加了土壤有机质。     

混合菌修复石油污染土壤

选取4种从石油污染土壤中分离出的石油降解菌(包括根瘤菌(A)、节细菌(B)、嗜盐菌(C)和芽孢杆菌(D)),对模拟石油污染土壤进行了微生物修复实验。考察了4种菌单独使用时的石油降解率,确定了混合菌的最佳配比和菌群的最优培养条件,并对比了微生物修复前后土壤的各项性质。实验结果表明:4种菌均可提高微生物修复石油污染土壤的修复效果,使用D菌时石油降解率最高;当混合菌的w(A)∶w(B)∶w(C)∶w(D)=12∶2∶21∶65时,在培养条件为混合菌接种量122.0 mL/kg、土壤含水率14%(w)、鸡粪加入量90 g/kg、麦糠加入量150 g/kg和表面活性剂加入量22 mL/kg的情况下,土壤的修复效果最好,40 d后石油降解率达66.95%;经混合菌修复的石油污染土壤,其肥力明显升高,脱氢酶、过氧化酶和脲酶的活性均升高,微生物数量也有明显增加。     

混合菌修复石油污染土壤

选取4种从石油污染土壤中分离出的石油降解菌（包括根瘤菌（A）、节细菌（B）、嗜盐菌（C）和芽孢杆菌（D）），对模拟石油污染土壤进行了微生物修复实验。考察了4种菌单独使用时的石油降解率，确定了混合菌的最佳配比和菌群的最优培养条件，并对比了微生物修复前后土壤的各项性质。实验结果表明：4种菌均可提高微生物修复石油污染土壤的修复效果，使用D菌时石油降解率最高；当混合菌的w（A）∶w（B）∶w（C）∶w（D）=12∶2∶21∶65时，在培养条件为混合菌接种量122.0 mL/kg、土壤含水率14%（w）、鸡粪加入量90 g/kg、麦糠加入量150 g/kg和表面活性剂加入量22 mL/kg的情况下，土壤的修复效果最好，40 d后石油降解率达66.95%；经混合菌修复的石油污染土壤，其肥力明显升高，脱氢酶、过氧化酶和脲酶的活性均升高，微生物数量也有明显增加。     

石油烃污染土壤微生物修复促进技术

采用原位修复法处理石油烃污染土壤,考察了土壤中石油烃的自然降解情况,研究了土壤改良剂和生物营养剂对石油烃降解的促进作用。实验结果表明:将总石油烃含量约为5 g/kg的实验土样降解30 d,自然降解时总石油烃降解率为7.8%;当单独加入1.0%(w)的土壤改良剂时,总石油烃降解率达36.0%;当单独加入1.0 g/kg的生物营养剂时,总石油烃降解率为51.6%;最佳促进剂配方为土壤改良剂加入量1.0%(w),生物营养剂加入量1.0 g/kg,此条件下总石油烃降解率为80.1%。     

过氧化氢、过碳酸钠活化过硫酸钠氧化—微生物降解联用技术修复原油污染土壤

分别以H₂O₂和Na₂CO₃·1.5H₂O₂活化Na₂S₂O₄降解原油污染土壤,考察氧化后土壤的原油降解率、pH、微生物含量以及原油组分的变化,比较两种活化剂对过硫酸钠氧化—微生物降解联用技术修复原油污染土壤效果的影响。实验结果表明：两种活化剂氧化处理7 d后的最大原油降解率分别达到42.94%和44.07%;氧化后原油组分的占比情况发生变化,w（饱和烃）增加5.28~11.93个百分点,而w（芳香烃）、w（胶质）和w（沥青质）则分别降低了0.10~2.53,2.53~3.80,0.94~3.43个百分点;添加微生物菌剂进行50 d的生物降解后,两种活化剂的最大原油降解率分别达到71.00%和75.70%,比单独微生物降解时提高了5.96~12.08个百分点。     

黑麦草-不动杆菌组合体系对石油污染土壤的生物强化修复

以盆栽实验为基础，研究了植物（黑麦草，Lolium perenne L）-微生物（不动杆菌，Acinetobacter sp.）组合体系对石油污染土壤的修复效果。实验结果表明：在总石油烃含量为4 420.18 mg/kg、脱氢酶活性为230.52 μg/（g·d）、苯酚毒性当量浓度（TEQphenol）为1 633.21 mg/L的初始条件下，强化组总石油烃降解率最高为53.08%，是对照组的1.60倍；土壤的脱氢酶活性达到637.73 μg/（g·d），是对照组的10.64倍；石油污染土壤的生物毒性大幅降低， TEQphenol最终降低至171.08 mg/L。说明该组合体系对石油污染土壤具有很好的修复作用，且微生物对土壤中有毒物质的降解起主要作用。     

生物刺激与生物强化联合修复柴油污染土壤

从柴油污染土壤中筛选分离出一株高效降解柴油的菌株CY-1,考察了自然衰减修复、生物刺激修复、生物强化修复以及生物刺激-生物强化联合修复等4种修复方法对土壤中柴油的降解能力及降解过程中几种土壤微生物酶活性的变化。实验结果表明:该菌为假单胞菌属;采用生物刺激-生物强化联合修复初始柴油质量分数为2.70%的柴油污染土壤,经过31 d的降解,柴油质量分数降至1.09%,柴油去除率达59.6%;经生物刺激-生物强化联合修复,土壤脱氢酶活性和荧光素二乙酸酯水解酶活性最高;通过生物刺激处理可使土壤脲酶活性和磷酸酶活性达到最高。     

表面活性剂对土壤中石油污染物的解吸

采用4种表面活性剂解吸老化石油污染土壤中的污染物,对其解吸动力学特征及残油组分进行了分析。实验结果表明:在表面活性剂质量浓度相同(0.5 g/L)条件下,土壤中石油污染物解吸率的大小顺序为十二烷基硫酸钠(SDS)曲拉通X-100(TX-100)吐温-80(TW-80)十二烷基苯磺酸钠(SDBS);SDS的解吸率最高,经48 h累积解吸后土壤中石油污染物的解吸率为38.7%;表面活性剂对石油污染物的解吸动力学曲线用Elovich方程拟合,效果最好,相关系数为0.970 2~0.995 6;非离子表面活性剂(TX-100、TW-80)对石油污染物中饱和烃组分的解吸率优于阴离子表面活性剂(SDS、SDBS),而对芳香烃组分的解吸率不如阴离子表面活性剂。     

Lysinibacillus sphaericus and Geobacillus sp Biodegradation of Petroleum Hydrocarbons and Biosurfactant Production

Petroleum oil is a major driver of worldwide economic activity, but it has also created contamination problems during the storage and refining process. Also, unconventional resources are natural resources, which require greater than industry‐standard levels of technology or investment to exploit. In the case of unconventional hydrocarbon resources, additional technology, energy, and capital have to be applied to extract the gas or oil. Bioremediation of petroleum spill is considered of great importance due to the contaminating effects on human health and the environment. For this reason, it is important to reduce total petroleum hydrocarbons (TPH) in contaminated soil. In addition, biosurfactant production is a desirable property of hydrocarbon‐degrading microorganisms. Seven strains belonging to Lysinibacillus sphaericus and Geobacillus sp were selected to evaluate their ability to biodegrade TPH in the presence of toxic metals, their potential to produce biosurfactants, and their ability to improve the biodegradation rate. The seven bacterial strains examined in this study were able to utilize crude petroleum‐oil hydrocarbons as the sole source of carbon and energy. In addition, their ability to degrade crude oil was not affected by the presence of toxic metals such as chromium and arsenic. At the same time, the strains were able to reduce toxic metals concentration through biosorption processes. Biosurfactant production was determined using the drop‐collapsed method for all strains, and they were characterized as both anionic and cationic biosurfactants. Biosurfactants showed an increase in biodegradation efficiency both in liquid minimal salt medium and landfarming treatments. The final results in field tests showed an efficiency of 93 percent reduction in crude oil concentration by the selected consortium compared to soil without consortium. The authors propose L. sphaericus and Geobacillus sp consortium as an optimum treatment for contaminated soils. In addition, production of biosurfactants could have an application in the extraction of crude oil from unconventional hydrocarbon resources. © 2014 Wiley Periodicals, Inc.     

Biodegradation of Aliphatic and Aromatic Hydrocarbons: Specificity among Bacteria Isolated from Refinery Waste Sludge

Indigenous microorganisms, enriched and isolated from refinery waste sludge, were observed to possess a broad range of metabolic activities for mixtures of several classes of substrates of petroleum hydrocarbons, such as monoaromatic and polycyclic aromatic hydrocarbons (PAHs) and n- and branched alkanes. Three of the best-growing bacterial isolates selectively enriched with these compounds were identified by 16S rDNA sequencing as belonging to the genera Enterobacter and Ochrobactrum. Two of them, Enterobacter sp. strain EK3.1 and Ochrobactrum sp. strain EK6 utilise a hydrocarbon mixture of the branched alkane 2,6,10,14-tetramethylpentadecane and the PAHs acenaphthylene and acenaphthene. Enterobacter sp. strain EK4 can grow with a mixture of 2,6,10,14-tetramethylpentadecane, toluene, acenaphthylene and acenaphthene as carbon sources. Nucleic acid fingerprint analysis, by terminal restriction fragment length polymorphism (T-RFLP) of the PCR-amplified 16S rRNA genes, of the autochthonous bacterial community in contaminated soil samples showed complex and different community structures under different treatments of refinery waste sludge in landfarm areas. The characteristic peaks of the T-RFLP profiles of the individual, isolated degrading bacteria Enterobacter spp. and Ochrobactrum sp. were detected in the T-RFLP fingerprint of the bacterial community of the four months old treated landfarm soil, suggesting the enrichment of bacteria belonging to the same operational taxonomic units, as well as their importance in degrading activity.     

铁活化过硫酸盐修复石油烃污染土壤的研究进展

分析了Fe~0、Fe~(2+)和Fe~(3+)活化过硫酸盐氧化石油烃的机理,介绍了土壤中石油烃污染物降解的影响因素以及总结了铁活化过硫酸盐修复石油烃污染土壤技术的不足。指出应以铁活化过硫酸盐原位修复作为土壤中高浓度有机污染物的前处置方法,再结合微生物或植物修复等技术,以减少对土壤理化性质的影响;另外,检测仪器的发展有利于土壤修复技术的应用。     

Operation of a 27‐m3 biopile for the treatment of petroleum‐contaminated soil

Soil and groundwater contamination due to petroleum hydrocarbon spills is a frequent problem worldwide. In Mexico, even when programs oriented to the diminution of these undesirable events exist, in 2000, a total of 1,518 petroleum spills were reported. Exploration zones, refineries, and oil distribution and storage stations frequently are contaminated with total petroleum hydrocarbons (TPH); diesel fraction; gasoline fraction; benzene, toluene, ethyl benzene, and xylenes (BTEX); and polycyclic aromatic hydrocarbons (PAHs). Among the many methodologies available for the treatment of this kind of contaminated soil, bioremediation is the most favorable, because it is an efficient/low‐cost option that is environmentally friendly. This article discusses the capability of using a biopile to treat soils contaminated with about 40,000 mg/kg of TPH. Design and operation of a 27‐m³ biopile is described in this work, including microbiological and respirometric aspects. Parameters such as TPH, diesel fraction, BTEX, and PAHs considered by the U.S. Environmental Protection Agency were measured in biopile samples at 0, 2, 4, 6, 8, 10, and 22 weeks. A final average TPH concentration of 7,300 mg/kg was achieved in 22 weeks, a removal efficiency of 80 percent. © 2007 Wiley Periodicals, Inc.