石油烃污染土壤的生物修复

从中原油田污染土壤中通过实验室驯化培养分离到一组能以中原原油为碳源的快速生长的石油烃降解菌.用该组降解菌接种原油污染土壤,研究其原位生物联合修复实验,接种降解菌的各区分别种植大豆、施有机肥料、施有机肥料和锯末,与空白试样作对比.经过120d的联合修复,各区石油降解菌的总数(lgcfu/g)由接种时的5.25分别变为7.79、4.96、5.15、4.67.石油烃降解率分别达到89.4%、72.5%、76.7%、49.2%.表明分离的该组石油烃降解菌是一组高效降解菌且其与植物联合修复石油污染土壤能显著提高修复效果.     

石油烃污染及修复过程中的微生物分子生态学研究进展

针对环境中广泛存在的石油烃污染问题,从分子生态学的角度总结石油烃降解过程中的微生物生态学研究进展。着重介绍分子生态学的研究方法及与石油烃降解相关的降解基因和基因芯片的最新研究进展,同时对存在的问题和今后的研究方向进行总结。     

植物修复石油烃污染土壤的机制

根据石油烃污染土壤植物修复的应用和研究现状,对近年来国内外植物修复机制进行阐述与探讨。植物首先通过根系直接吸收石油烃,并利用自身的新陈代谢或植物内生菌的协作将其去除。石油烃一旦被根系吸收,植物就会通过木质化作用将其储存在组织中,或通过植物挥发或植物降解将其转化成一些低毒的中间代谢产物或CO_2和H2O;而植物内生菌与植物降解、植物修复以及植物保护密切相关。其次,根际分泌物和根际微生物在石油烃污染土壤根际修复方面起到重要作用。根际是受根系活动影响的一个微生态区,因而可以认为根际修复是去除土壤中石油烃的主要方式。植物根系可以向根际释放一些分泌物和酶类。其中,酶可以直接作用于石油烃,对石油烃的降解起到关键的作用;而根际分泌物可以向根际微生物提供碳源、能源或共代谢物,使根际微生物数量和活性明显高于非根际,生物降解作用增强。今后可以从根际分泌物作用的微生态过程、功能基因的寻找和构建、厌氧氧化的过程和机制、植物内生菌的作用和应用,以及利用组学手段研究植物修复机制5个方面开展工作,以期望为未来植物修复工作提供重要的科学支持。     

考洲洋饵料生物水平综合评价

在GIS(Geographical Information System)的支持下,利用等级模型对1999年2月(枯水期)和8月(丰水期)考洲洋饵料生物水平进行了综合的分析和评价。枯水期考洲洋整个水域饵料生物的分布较均匀,其密集分布区位于湾西北部、湾口和吉隆河口附近水域,达4级水平,饵料生物较为丰富。丰水期饵料生物水平的变化幅度较大,其密集分布区位于湾中部和望京洲沿岸水域,达4-5级,饵料生物最为丰富,其次为湾口,达4级水平。两个调查航次相比,丰水期的饵料生物水平高于枯水期。主要优势种的变化具有明显的季节交叉和演替现象,浮游植物和浮游动物的主要优势种在不同季节差异较大,而底栖生物的优势种组成在整个调查期间变化不大。调查期间各饵料生物的多样性指数和均匀度均呈现出较大的变化,其最大变化范围分别为0.01-4.49和0.01-0.96,表明湾内饵料生物受外界环境条件影响较大,生物群落组成结构和生物多样性水平不太稳定。调查期间整个水域的生物多样性阈值均呈现出湾西部及西北部水域较高,其余水域较低的分布特点,但不同季节其变化趋势及分布范围略有差异。枯水期多样性阈值的密集分布区出现于湾西侧的部分水域,其等级水平为3级,饵料生物多样性较好,其余水域均为2级或低于2级水平,多样性一般或较差。丰水期的分布趋势与枯水期相似,其密集区出现于湾西部和西北部的整片水域中,分布范围比枯水期大,但等级水平明显低于枯水期,为2级,多样性一般,其余大部分水域均为1级水平,多样性较差。       

小黑麦对石油污染盐碱土壤细菌群落与石油烃降解的影响

为了研究小黑麦对石油污染盐碱土壤中的细菌群落与石油烃降解率的影响,采用高通量测序技术,设置0 g/kg,1 g/kg和5 g/kg三个石油浓度,以未种植小黑麦的土壤作为对照,对6组不同处理的盐碱土壤样品的细菌群落结构及其多样性进行测定,并分析土壤中的石油烃降解率。结果表明:在土壤石油浓度为1 g/kg和5 g/kg时,小黑麦根际土壤中的石油烃降解率相较对照组分别提高了36.67%和33.20%。从6个土壤样品中分别获得21398—27899条测序序列。在石油污染土壤中,小黑麦根际土壤的细菌群落多样性和丰度均大于对照组的土壤。同时,在"门","纲","属"的分类水平上,小黑麦根际土壤细菌群落中的一些根际细菌的相对丰度增加了,主要包括变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、γ-变形菌纲(Gammaproteobacteria)、烷烃降解菌科-未命名菌属(Alcanivoracaceae_norank)、黄单胞菌属(Xanthomonas)、亚硝化单胞菌-不可培养菌属(Nitrosomonadaceae_unculture)等。有一些相对丰度增加的根际细菌是以石油及石油分解物为碳源的微生物。本研究证明种植小黑麦改变了石油污染盐碱土壤根际土壤细菌群落结构组成和多样性,促进了降解石油微生物群落的构建,显著提高了盐碱土壤石油污染的降解效果。研究结果为石油污染盐碱土壤的植物修复奠定了理论基础。     

印度洋深海沉积物石油烃降解菌分离、鉴定与多样性分析

烃类物质在海洋环境中广泛分布,深海可能含有特殊的烃降解微生物。本研究通过对西南印度洋中脊与印度洋中部深海沉积物中石油降解菌的富集培养和分离鉴定,从6个站点的样品中共分离得到800株菌,通过BOX-PCR去重复菌株后,对其中183株菌进行了16S rRNA基因序列分析,发现这些菌分属于23个属;其中,γ-变形菌纲的食烷菌属(Alcanivorax)和放线菌纲的微杆菌属(Microbacterium)占优势。此外,还发现了食烷菌属2个潜在的新种、假海栖菌属(Pseudooceanicola)1个潜在新种。高通量测序结果证明,富集菌群中γ-变形菌纲是优势菌,主要包括食烷菌属、盐单胞菌属(Halomonas)、海杆菌属(Marinobacter)等。结合可培养菌与高通量测序结果,食烷菌属、盐单胞菌属、海杆菌属、交替假单胞菌(Pseudoalteromonas)、海源菌属(Idiomarina)与微杆菌属(Microbacterium)是沉积物样品中常见的石油烃降解菌,迪茨氏菌属(Dietzia)、红球菌属(Rhodococcus),假单胞菌属(Pseudomonas)、赤杆菌属(Erythrobacter)与副球菌属(Paracoccus)等可能也参与了烃的降解。     

石油烃生物降解过程的研究进展

石油烃污染物属于难降解混合物,生物修复已经成为石油烃污染环境的主要修复方法.文中简述了微生物对石油烃的间期适应过程和转运过程,并通过对部分典型石油烃成分的微生物降解机理和代谢路径的梳理和综述,阐释了石油烃生物降解过程中的菌株、基因、代谢路径等研究进展.此外,利用基因工程和代谢工程等手段,可对野生型石油烃降解菌进行改造,...     

石油烃降解菌的筛选与鉴定

从胜利油田的石油污染土壤中经富集培养分离出50株细菌,其中33株菌在以石油为惟一碳源和能源的选择性培养基中生长良好.采用紫外分光光度法对菌株的降解能力进行测定,结果有16株菌在石油初始浓度为2 500 mg·L-1的培养液中振荡培养4 d降解率超过30%,其中PU-34、PU-15、PU-2、PU-4、PU-1降解能力较高,4 d能够使石油烃类含量分别减少58.38%、55.55%、55.17%、53.09%、52.36%,在生物修复石油污染技术中具有应用前景.结合形态特征观察、生理生化特性和16S rDNA序列分析的方法对这5株菌进行菌种鉴定,确定PU-34为假黄单胞菌(Pseudoxanthomonas sp.),PU-15和PU-2为戈登氏菌(Gordonia sp.),PU-4为红球菌(Rhodococcus sp.),PU-1为假单胞菌(Pseudomonas sp.).     

微生物修复石油烃土壤污染技术研究进展

随着人民生活水平的提高,环境保护问题愈发受到人们重视。其中石油烃的土壤污染因其持续时间长、污染去除难度大而受到广泛关注。在各类修复技术中,原位微生物修复强化技术因其成本较低、环境影响小、无二次污染、可原位修复的特点成为了当前的技术热门。文中综述了生物投加法、生物刺激法、联合修复法等原位微生物修复技术,并介绍了一些典型工程案例,为原位微生物修复强化技术的选择及工程应用提供了参考,并对未来原位微生物修复强化技术的研究重点进行了展望。     

鼠李糖脂对微生物降解石油烃废水的影响

目的:研究鼠李糖脂对微生物降解石油烃废水的影响.方法:通过测定生物量和观察菌株表面来研究鼠李糖脂对菌株的影响;通过正交实验设计,确定石油烃降解率影响因素.通过石油烃降解率的测定,探讨鼠李糖脂与H2O2深度氧化协同作用对微生物降解石油烃的影响.结果:菌株对石油烃的降解率达53%,在相同条件下,添加鼠李糖脂的石油烃降解率提高了12%-20%.添加鼠李糖脂后菌株的生物量明显增多,菌株细胞表面疏水.正交设计表明,影响石油烃降解的主导因子是培养温度,其次是培养时间和鼠李糖脂的添加量.正交设计得到最佳组合为A3B2C1,即培养时间为7d;温度为35℃,鼠李糖脂浓度为60mg/L.3个因素的最佳组合下,石油烃降解率为82%.加入200 mg/L的H2O2时,降解率从82%提高到97%.结论:鼠李糖脂能促进菌株的生长.鼠李糖脂与H2O2深度氧化协同作用有助于微生物对石油烃类污染物降解效率的提高.     

考洲洋重金属污染水平与潜在生态危害综合评价

在等级模型的基础上,利用化学和生态学的方法,在地理信息系统(GIS)的支持下对考洲洋养殖水域表层海水及表层沉积物的重金属污染水平及潜在生态风险进行了综合评价,同时对不同的评价方法进行了分析和比较。结果表明,枯水期整个水域表层海水的重金属污染指数均低于0．5,丰水期更是低于0．2。调查期间湾内海水重金属含量较低,重金属污染不明显。枯水期绝大部分水域表层沉积物重金属的生态风险指数值变化范围为20～70,其高值区出现于湾的西部和西北部水域。表明这些水域的表层沉积物已受到重金属的轻微影响;丰水期整个水域表层沉积物重金属的潜在生态风险指数值均低于20,重金属污染不明显。在生态学方面,枯水期大部分水域的饵料生物水平均处于2～3级水平,其密集分布区位于湾西北部、湾口和吉隆河口附近水域,达4级水平,饵料生物较为丰富。丰水期饵料生物水平的密集分布区位于湾中部和望京洲沿岸水域,饵料生物最丰富,达4～5级水平;其次为湾口,为4级水平;最低则分布于湾的西部和西北部,其饵料生物较低,为1～2级水平。由于重金属污染程度较低,因此水温、盐度和营养盐等环境因子已成为影响湾内生态系统的主要因素。对各种不同评价方法所进行的分析和比较结果表明,采用多指标综合评价方法是描述污染和预测生态效应的一种有效途径。     

Bioremediation and phytoremediation of total petroleum hydrocarbons (TPH) under various conditions

Remediation of contaminated soils is often studied using fine-textured soils rather than low-fertility sandy soils, and few studies focus on recontamination events. This study compared aerobic and anaerobic treatments for remediation of freshly introduced used motor oil on a sandy soil previously phytoremediated and bioacclimated (microorganisms already adapted in the soil environment) with some residual total petroleum hydrocarbon (TPH) contamination. Vegetated and unvegetated conditions to remediate anthropogenic fill containing residual TPH that was spiked with nonaqueous phase liquids (NAPLs) were evaluated in a 90-day greenhouse pot study. Vegetated treatments used switchgrass (Panicum virgatum). The concentration of aerobic bacteria were orders of magnitude higher in vegetated treatments compared to unvegetated. Nevertheless, final TPH concentrations were low in all saturated soil treatments, and high in the presence of switchgrass. Concentrations were also low in unvegetated pots with fertilizer. Acclimated indigenous microbial communities were shown to be more effective in breaking down hydrocarbons than introducing microbes from the addition of plant treatments in sandy soils. Remediation of fresh introduced NAPLs on pre-phytoremediated and bioacclimated soil was most efficient in saturated, anaerobic environments, probably due to the already pre-established microbial associations, easily bioavailable contaminants, and optimized soil conditions for microbial establishment and survival.     

Potential of vetiver (vetiveria zizanioides (L.) Nash) for phytoremediation of petroleum hydrocarbon-contaminated soils in Venezuela

Venezuela is one of the largest oil producers in the world. For the rehabilitation of oil-contaminated sites, phytoremediation represents a promising technology whereby plants are used to enhance biodegradation processes in soil. A greenhouse study was conducted to determine the tolerance of vetiver (Vetiveria zizanioides (L.) Nash) to a Venezuelan heavy crude oil in soil. Additionally, the plant's potential for stimulating the biodegradation processes of petroleum hydrocarbons was tested under the application of two fertilizer levels. In the presence of contaminants, biomass and plant height were significantly reduced. As for fertilization, the lower fertilizer level led to higher biomass production. The specific root surface area was reduced under the effects of petroleum. However, vetiver was found to tolerate crude-oil contamination in a concentration of 5% (w/w). Concerning total oil and grease content in soil, no significant decrease under the influence of vetiver was detected when compared to the unplanted control. Thus, there was no evidence of vetiver enhancing the biodegradation of crude oil in soil under the conditions of this trial. However, uses of vetiver grass in relation to petroleum-contaminated soils are promising for amelioration of slightly polluted sites, to allow other species to get established and for erosion control.     

Effect of salinity on the bioremediation of petroleum hydrocarbons in a saline-alkaline soil

Aims: The aim of this paper is to check the effect of salinity on the bioremediation process of petroleum hydrocarbons in the saline‐alkaline soil. Methods and Results: In this study, soil salinity was adjusted to different levels by water leaching method and the bioremediation process was conducted for 28 days. Soil pH increased after leaching and decreased during bioremediation process. At initial time, moderate salinity enhanced the biodegradation and addition of microbial consortium was not effective in enhancing degradation rate of petroleum hydrocarbons. At day of 28 days, higher degradation rate was found in treatments with more leaching times with a maximum value of 42·36%. Dehydrogenase activity increased with the progress of bioremediation and positive correlation was found between dehydrogenase activity and degradation rate of petroleum hydrocarbons. Denaturing gradient gel electrophoresis analysis result showed decreased microbial community diversity with increased salt content. Conclusions: The result suggested that salinity had great impact on bioremediation, and leaching and addition of inoculated consortium were effective in enhancing biodegradation of petroleum hydrocarbons in the saline‐alkaline soil. Significance and Impact of the Study: The result of this study is important for understanding the bioremediation process of petroleum in contaminated soil. New remediation method of petroleum contaminated soil can be developed based on this study.     

全氟辛酸在沉积物-水界面污染及吸附迁移行为研究进展

全氟辛酸(PFOA)是一种重要的全氟化表面活性剂,具有环境持久性、高毒性和生物累积性等特征,成为当前备受关注的新污染物。沉积物是PFOA的重要环境储蓄库,被污染后的沉积物可作为长期污染源造成上覆地表水及周边地下水污染。本文结合近年来国内外研究,对地表水和沉积物中PFOA的来源、污染现状和界面吸附迁移行为进行了综述。结果表明: 地表水体和沉积物中PFOA最主要的污染来源为工业废水排放。全球范围地表水体和沉积物中PFOA污染水平普遍为ng·g^-1和ng·L^-1数量级,且国内部分地区污染形势更为严峻。沉积物组分、水化学条件、有机质及表面活性剂等因素均影响沉积物中PFOA的吸附行为,但目前在吸附主控机制方面仍然存在争议。沉积物中PFOA迁移行为的研究正处于起步阶段,相关报导还较为缺乏,对于迁移机理的认识还很不足,今后需在该方面加大研究力度。     

GIS支持下考洲洋养殖水域浮游植物数量的时空分布及其与营养盐的相关性研究

在GIS和统计分析软件SPSS的支持下,利用数据插值、相关性分析和回归分析等方法,研究了枯水期和丰水期考洲洋养殖水域浮游植物数量的分布趋势及其与海水营养盐的相关关系。结果表明,枯水期浮游植物数量的分布较为均匀,其密集区分布于吉隆河口及其附近水域;而丰水期的数量变化幅度较大,密集分布区出现在湾口至盐洲岛北部水域,呈现出从湾西北部至湾口水域逐渐增加的分布趋势。两次调查相比,丰水期浮游植物的数量明显高于枯水期。相关性研究结果表明,调查期间浮游植物数量与无机氮和无机磷的相关性均不显著,但与活性硅酸盐呈显著相关,在枯水期两者之间呈显著正相关,而在丰水期则刚好相反,两者之间呈显著负相关。     

宽甸县水中硼的背景浓度及污染现状分析

采集辽宁宽甸县各种水样51个,用ICP—MS分析硼含量。结果表明,宽甸县水中硼含量的背景值与世界水平相当,污染地区地表水和地下水硼含量的平均值分别是背景点的23．1和495．6倍。硼的开采和加工对水体产生了较严重的硼污染。     

Technical note: fate and transport of jet fuel (JP-8) in soils with selected plants

Remediation of soil and groundwater contaminated by leaking fuel storage tanks may be assisted by plants, although plant effects on abiotic and biotic removal processes remain unclear. The objectives of this study were to investigate abiotic and biotic removal of JP-8, a kerosene-based jet fuel, in soils with plants, and to determine the effects of plant-induced water movement. Loss of JP-8 in a dry-soil, control column was 25% after 5 months, primarily due to volatilization and gas-phase diffusion. By comparison, managed treatments with simulated surface spills averaged 86% mass reduction at 5 months, indicating an important contribution of biodegradation. Overall JP-8 mass reduction was similar in surface and subsurface-irrigated systems, indicating water content, not mode of water application, influences bioremediation in near-surface systems. The JP-8 concentration reductions in soil columns contaminated above a simulated watertable were 36% after 3 months and 50% after 12 months for vegetated columns compared to 26% and 34% in unplanted columns. Downward movement of JP-8 in unplanted columns was double that in planted columns. Near the groundwater table, JP-8 persists longer than near the soil surface. Plants promote upward movement of water and help draw spilled JP-8 to aerobic near-surface soil.