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1.
以2010年6月在东北某油田区野外调查获取的68个表层土壤样品和50个钻孔土壤样品总石油烃浓度测试结果为基础,运用相对累积概率分布曲线法确定该区土壤总石油烃背景值(或临界值),采用监测断面分析法、比拟法对所得结果进行验证,并以此为依据分析了研究区不同土地利用类型表层土壤和不同深度土壤中石油烃污染特征,进而对土壤石油烃污染程度进行评价。结果表明:运用相对累积概率分布曲线法所确定研究区土壤总石油烃背景值(或临界值)为10mg/kg。研究区芦苇湿地土中66.7%点位属中等及以上污染水平,稻田耕作土中73.1%点位属未污染或低污染水平;表层土壤总石油烃浓度空间变异性较大,表现出明显的点源污染特征。此外,表层土壤总石油烃浓度明显高于深层土壤,0～0.2m土层达到重度污染水平,以下深度总石油烃浓度逐渐降低,趋向背景值。这种情况与污染场地石油烃在垂向上的迁移过程主要以渗透作用为主有关。 相似文献
2.
气相色谱法测试土壤中分段石油烃的标准化定量方法初探 总被引：2，自引：1，他引：1
目前土壤样品中分段石油烃的分析方法中石油烃包括的碳原子数范围和采用的校准物质不统一,造成不同实验室的量值不具有可比性。为保证不同实验室之间结果的可比性,本文尝试建立一种石油烃相邻碳原子数标准化定量方法。该方法主要包括:(1)规定了石油烃包括的碳原子数范围为气相色谱峰中正己烷和正四十碳烷之间所有的烃(含正己烷);(2)总石油烃(TPH)分为挥发性石油烃(VPH)和半挥发性石油烃(SPH),分别选取碳原子数为6～10的5个正构烷烃作为VPH校准物质,选取碳原子数为10～40的31个正构烷烃作为SPH校准物质。采用平均响应因子法或一次线性回归法,建立校准物质的峰面积-浓度的校准关系;(3)采用相邻峰标准化校准方法,逐一定量所有的目标色谱峰;(4)计算正构烷烃含量、总石油烃含量和任意分段的石油烃含量。该方法为环境样品中石油烃分析方法的标准化建设提供了数据基础。 相似文献
3.
土壤中不同形态砷的分析方法 总被引：5，自引：1，他引：4
选取磷酸作为提取剂,比较了超声和水浴两种方法辅助提取土壤中不同形态的砷,离子色谱一氢化物发生原子荧光光谱联用法(IC-HGAFS)测定砷的4种形态,即As(Ⅲ)、As(Ⅴ)、MMA (甲基胂酸)和DMA(二甲基胂酸)。从测定结果可以看出,水浴的提取效果明显高于超声的提取效果。土壤中砷以无机态为主,而无机态砷又以As(Ⅴ)为主,没有检测到有机砷。测定土壤中各种形态砷的加标回收率为72.0%～105.4%,相对标准偏差(RSD,n=5)为2.61%～8.19%。 相似文献
4.
从长江经济带某在役石化场地采集了3个点位不同深度的土壤样品,测定了石油烃等污染物的含量和微生物的群落结构,以揭示污染物分布规律和微生物特征。结果显示,3个点位污染程度不同,但污染物含量均随深度先升高后降低,最高含量均出现在埋深4.0 m左右,即地下水位附近。土壤中C6-C9高达5 302 mg/kg,C10-C40高达625.6 mg/kg,芳烃高达455.2 mg/kg,卤代烃高达41.54 mg/kg。土壤微生物的丰富度和多样性随深度增加而降低,同一深度土壤微生物的丰富度和多样性随污染物含量增大而降低。门水平上Actinobacteria、Firmicutes和Spirochaetes的相对丰度和石油烃含量显著正相关(p<0.05),属水平上Streptomyces、SCADC1-2-3、Desulfitobacterium和Cryptanaerobacter的相对丰度和石油烃含量显著正相关(p<0.05)。 相似文献
5.
在铁观音茶叶主产区福建省安溪县27个茶园采集了表层(0~20 cm)和亚表层(20~40 cm)土壤,风干过2 mm筛后,采用超声振动筛进行筛分,并测定了粒级样品元素含量。结果表明:(1)2000~840μm和840~250μm的大团聚体颗粒占土壤样品重量的73%左右,而250~125μm、125~63μm和63μm 3种微团聚体约占27%;(2)大团聚体与微团聚体量的比值与土壤Si O2呈反比,与Al2O3、Fe2O3呈正相关,说明富含黏土矿物和铁铝氧化物有利于大团聚体颗粒的形成。土壤大团聚体与微团聚体中Cd、Cr、Hg、Ni、P、Al等多数元素指标的浓度差异明显,除了Si O2、Mn外,其他指标均不同程度地自粗粒级向细粒级逐渐增加,以P、Zn、Zr、Corg最为明显;(3)浸提实验表明,水提取态元素浓度最低,As、Cu、Pb、Zn浸提量由水提取—NH4NO3提取—稀盐酸提取—DTPA提取逐步增加;对于其他元素,稀盐酸提取态Cd、Se较高,NH4NO3提取态Mn、Ni较高,Hg则以NH4NO3提取态和DTPA浸提态较高。表层土壤中多数元素浸提浓度高于亚表层土壤,推断与表层土壤有机碳较高有关。 相似文献
6.
多环芳烃(PAHs)是一类具有致癌、致突变、致畸的碳氢化合物,具有较高的辛醇-水分配系数,易被土壤颗粒吸附而影响环境和人体健康。过硫酸钠(Na2S2O8)氧化法是近些年来国内外修复PAHs污染土壤较为常用的方法,但现阶段在测定修复后土壤中PAHs含量、进行土壤修复效果评估时亟待解决的问题是：经该方法修复的土壤,若土壤中残留有过硫酸钠,在样品前处理过程中由于提取温度较高,可能会进一步加速多环芳烃的氧化反应,从而影响土壤中PAHs的准确测定。本文建立了一种在修复后土壤中加入还原剂抗坏血酸,与残留的过硫酸钠反应生成脱氢抗坏血酸,采用索氏提取结合气相色谱-质谱法(GC-MS)同时测定土壤中16种PAHs的方法,PAHs加标回收率为76.2%～110.0%。而修复后土壤若不加还原剂直接进行索氏提取,用GC-MS测定,可能会使部分PAHs及替代物的测定不准确,PAHs加标回收率仅为6.0%～72.4%。通过对比分析表明,在样品提取前加入还原剂,可以有效地消除残留过硫酸钠的影响,提高测定修复后土壤中PAHs含量的准确性。 相似文献
7.
为了更好地对土壤中可提取态汞进行测定,针对目前常用的氯化钙提取-原子荧光光谱法测定土壤中可提取态汞的方法存在测定结果偏低和重现性差的问题,对该方法进行优化。研究采用在氯化钙提取液提取可提取态汞的滤清液中加入适量的重铬酸钾作为保护剂,以保护提取液中的汞不被器壁、溶液胶体吸附,从而解决溶液放置一段时间后测定结果偏低和重现性差的问题,同时考察了测定酸度、硼氢化钾浓度、提取温度、提取液浓度、土液比、提取时间和重铬酸钾的加入量对测定结果的影响,并优选出最佳条件：测定酸度为10%(V/V)的盐酸、硼氢化钾的浓度为10 g/L、提取温度为20℃±2℃、提取液浓度为0.01 mol/L、土液比为1∶10、提取时间为60 min、重铬酸钾的加入体积为2.0 mL。试验结果表明,以本试验推荐的最佳条件测定土壤中的可提取态汞,精密度(RSD,n=7)小于5%,相对误差(RE)小于5%,适用于土壤中可提取态汞的测定。 相似文献
8.
烃气测量是油气化探最主要的方法。目前应用的烃气测量方法有两类:一类是测量土壤中游离烃气如K—V指纹法、吸附丝法、物上气法及直接取土壤气测量法等。此类方法由于需特殊设备及壤气测量方法本身固有的缺陷,目前还未得到普遍应用,另一类为土壤吸附烃气法即国内外目前普遍使用的酸解烃气法、此法在多数油气田上取得好效果,但也有相当多的地区如黄土、荒漠及水网发育等特殊景观区效果不好或不显著。本文介绍一种新的烃气测量法──土壤相态烃测量法。这是用一种特殊的技术,只选择性提取由油气藏渗漏过程中保存在运移通道围岩及近地表土壤各种次生矿物结构中以"穴居"态存在的轻烃组分。"穴居"态烃为累积性的指标,不受外界温度、修水等的影响,保存较牢固,测定结果稳定。相态烃法避免了酸解烃法存在的生物成因烃、矿物同生烃及碳酸盐的干扰影响,提高了测量指标的信噪比,突出了应有的异常。本方法已在黄土厚覆盖区两个已知油气田和一个风成沙覆盖的断裂发育油田上试验获得成功,结果表明相态烃法优于酸解烃法。 相似文献
9.
加拿大阿尔伯塔省中部地区存在大量的上层是细颗粒土壤、下层是粗颗粒土壤的被石油烃（PHc）污染的双层土壤系统。针对这类土壤系统，本文构造出不同与J＆E模型的解析公式，以初步估计被石油烃污染的土壤或地下水挥发出的有机气体入侵建筑物的流量。应用ECCLIPSE-2003a软件对该区某污染场进行了数值模拟，以验证该公式。结果表明：在这类双层土壤系统中，该公式是有效的。 相似文献
10.
11.
L. G. B. Torres M. Climent J. Saquelares E. R. Bandala G. Urquiza R. Iturbe 《International Journal of Environmental Science and Technology》2007,4(3):311-322
A crude contaminated soil, arising from an oil production zone in Tabasco, Mexico was studied. A sample of about 40 kg was dried and screened through meshes 10–100. Total petroleum hydrocarbons and 6 metals (Cd, Cu, Cr, Ni, V and Zn) were determined to the different portions. For soil which passed mesh 10, six non-ionic, three anionic and one zwitterionic surfactant solutions (0.5%) were employed to wash the soil. Additional tests using surfactant salt mixtures and surfactants mixtures were carried out. Once the best soil washing conditions were identified, these experimental conditions were applied for washing the rest of the soil portions obtained (meshes 4, 6, 20, 40, 60, 80, 100). Total petroleum hydrocarbons values were in the range of 51, 550 to 192, 130 mg/kg. Cd was not found in any of the soils portions, and the rest of the metals were found at different concentrations, for every soil mesh. Treatability tests applied to the soils indicated that it is possible to get removals between 9.1 to 20.5%. For the case of a sodium dodecyl sulphate 1% solution, total petroleum hydrocarbons removal was as high as 35.4%. Combinations of sodium docecyl sulphate and salts, gave removal rates up to 49.5%. Total petroleum hydrocarbons concentrations for the whole soil were about 150,600 mg/kg. The higher the particle size, the lower the washing removal rate. The combined effect of particle size and total petroleum hydrocarbons concentration, determines the total petroleum hydrocarbons removal efficiencies. These facts are very important for designing an appropriate soil washing remediation process. 相似文献
12.
H.-C. Kuo D.-F. Juang L. Yang W.-C. Kuo Y.-M. Wu 《International Journal of Environmental Science and Technology》2014,11(6):1661-1668
The purpose of this study was to investigate the effect of phytoremediation on soils contaminated with heavy crude oil using plants infected by mycorrhizal fungi. Five plant species, Vetiveria zizanioides, Bidens pilosa, Chloris barbata, Eleusine indica, and Imperata cylindrica, infected with the species of mycorrhizal fungi Glomus mosseae, were selected for this study. The degradation of total petroleum hydrocarbons in soils and several physiological parameters of plants such as shoot length and biomass were analyzed. Out of the 5 plant species tested, only V. zizanioides, B. pilosa, and E. indica could take up the G. mosseae. Out of these three, V. zizanioides showed the greatest growth (biomass) in soils with 100,000 mg kg?1 total petroleum hydrocarbons. In addition, B. pilosa infected with G. mosseae was found to be able to increase degradation by 9 % under an initial total petroleum hydrocarbons concentration of 30,000 mg kg?1 in soils after 64 days. We conclude that plants infected with mycorrhizal fungi can enhance the phytoremediation efficiency of soils contaminated with high concentrations of heavy oil. 相似文献
13.
L. C. Osuji Ph.D. P. E. Ezebuiro 《International Journal of Environmental Science and Technology》2006,3(3):313-320
The impact of petroleum hydrocarbons on the floor of a mangrove system located on one of the intertidal lands behind the barrier islands of Niger Delta basin of southern Nigeria was evaluated following the Obiafu-14 oil spillage. The area covered by the oil spill was delimited by reconnaissance and soils were sampled by grid method from the bottom and middle slopes of oil-affected and unaffected (control) sites. Soil samples were later brought to the laboratory where total hydrocarbon content was determined by extraction and spectrophotometric techniques. A lower pH range of 4.28–4.36 in the oil impacted soils meant that the site was more acidic; a higher moisture content of 33.34% and lower electrical conductivity (EC) of 31.75μS/cm in the affected area presupposed oxygen deprivation and lower salt content respectively. On the strength of the baseline data on the study area and evidence from the uncontaminated, geographically similar control site, it can be said that the Obiafu-14 oil spillage had severely contaminated the affected mangrove floor. This is corroborated by a total extractable hydrocarbon content of 6.32×103 ± 344 mg/kg (no overlap in Standard Error at 95% Confidence Limit), and the abysmal degradation of the mangrove system at the site. Although soils of the mangrove floor under consideration may well be of limited cultivation value on account of the people’s dual occupation in fishing and farming, the presence of such levels of petroleum hydrocarbons at the study site might hamper agricultural productivity. 相似文献
14.
抗疏力固化剂在我国黄土加固中运用较少,探究抗疏力固化剂是否有利于维持黄土内部干燥状态很有必要。采用抗疏力固化剂对重塑Q3黄土改性,室内开展水滴入渗试验、柔性壁渗透试验、收缩试验及压力膜仪脱水试验,分别探讨抗疏力固化剂掺量对黄土进水、渗透及失水能力的影响。结果显示,随抗疏力固化剂掺量提高,土样斥水性急剧增大,明显优于粉煤灰、水泥、石灰改性土;渗透系数基本不变,水的流通性基本不变;干缩失水过程改性土样含水率及土-水特征曲线毛细作用区曲线斜率均变化不大,黄土失水能力基本不变。结合电镜及压汞试验结果可知,抗疏力固化剂对黄土中大孔隙、中孔隙体积含量影响较小,从而对黄土中水的流通及失去能力影响较少,证明抗疏力固化剂改性黄土斥水性明显提高,而失水能力基本不变,有利于维持黄土内部的干燥状态。 相似文献
15.
Evolution of soil-water states in the vadose zone of a desert soil after an extreme rainfall event and its impact on the ecosystem 总被引：1，自引：0，他引：1
Evolution of soil-water movement patterns following rare and extreme rainfall events in arid climates is not well understood, but it has significant effects on water availability for desert plants and on the hydrological cycle at small scale. Here, field data and the Hydrus-1D model were used to simulate the mechanisms of soil water and vapor transport, and the control factors associated with temporal variability in the soil water and temperature were analyzed. The results showed that thermal vapor transport with a no rainfall scenario determined daily variability in water content at the soil surface. During rainfall, isothermal liquid water fluctuated as a result of dry sandy soils and matric potential in the upper soil (0–25 cm), and thermally driven vapor played a key role in soil-water transport at 40–60 cm soil depth. After an extreme rainfall event, thermal vapor flux increased and accounted for 11.8% of total liquid and vapor fluxes in daytime with a steep temperature gradient; this was very effective in improving long-term soil-water content after the rain. The simulated results revealed that thermal water vapor greatly contributed to the soil-water balance in the vadose zone of desert soil. This study provided an alternative approach to describing soil-water movement processes in arid environments, and it increased understanding of the availability of water for a desert plant community.
相似文献16.
石油类有机物污染是地下水环境领域亟须解决的关键课题.本次研究耦合数值模拟和水文地球化学技术模拟岩溶裂隙含水层中石油类有机物的自然衰减过程并定量计算其自然衰减机制.基于BIOSCREEN模型的模拟计算可知,近30年对流、弥散、稀释等物理过程和生物降解过程对石油类有机物衰减贡献率的平均值分别为31.53%和68.47%,生物降解作用是岩溶裂隙含水层自然修复能力的主要机制.利用质量守恒定律分析水化学（HCO3-、NO3-）和同位素（δ15NNO3、δ18ONO3和δ13CDIC）之间的相关关系可知石油类有机物生物降解贡献地下水HCO3-的平均值为33.93%;石油类有机物生物降解消耗主要电子受体NO3-贡献地下水δ13CDIC的百分率为30.77%且其占总生物降解的90.69%. 相似文献
17.
Levels and sources of polycyclic aromatic hydrocarbons (PAHs) in selected irrigated urban agricultural soils in Accra, Ghana 总被引：2，自引：1，他引：1
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic pollutants in urban environments including urban soils. Elevated concentrations of PAHs in urban soils are caused by incomplete combustion of petroleum and coal. This study assesses 16 individual PAH compounds in a total of 112 surficial soil samples. The objective was to assess and compare the levels of contamination as well as examine the main sources of PAHs in four urban agricultural soils using molecular ratios of some specific hydrocarbons. The study showed that PAH levels in soil ranged from 1.23 ng/kg in soil collected from Dzorwulu to 2.95 ng/kg in soil collected from Ghana Broadcasting Cooperation (GBC) vegetable irrigation site. Of the total PAHs, the more water soluble PAHs (2–4 rings), which tend to be concentrated in the vapour phase were found to dominate the soils. The percentage dominance were Dzorwulu (52.8 %), Marine Drive (62.5 %), CSIR (53.2 %) and GBC (49.2 %). However, there were significant levels of the more carcinogenic PAHs (5–6 rings) present with percentages as 47.1, 37.5 46.8 and 50.8 % for Dzorwulu, Marine Drive, CSIR and GBC vegetable irrigation sites, respectively, and therefore, may impact negatively on public health. Based on the classification by the Institute of Soil Science and Plant Cultivation in Pulawy, Poland, urban soils in Accra could be classified as contaminated to different levels. Molecular ratios of Flu/pyr and PA/Ant were calculated to determine the main sources of PAHs. Results showed that PAHs could originate mainly from incomplete combustion of petroleum products, especially from atmospheric fallout from automobile exhausts. The study further showed that B(a)P concentration of 0.05 ng/kg in soil from GBC urban vegetable irrigation site requires immediate clean-up exercise and monitoring to mitigate human health impact. 相似文献
18.
《Applied Geochemistry》2003,18(6):915-926
In this paper, two small but practical case studies are presented that demonstrate the utility of detailed petroleum fingerprinting in investigating known or suspected pipeline releases. The two cases involve: (1) a known release of automotive gasoline from a product pipeline, which was accompanied by an intense fire, which prompted an investigation to determine the source of a peculiar, non-aqueous phase liquid (NAPL) discovered beneath the affected area during the accident’s clean-up and (2) a former trunk line pipeline from an oil field that was suspected as the source of a recently discovered NAPL. The known facts, analytical strategy, petroleum fingerprinting data and results for each case study are presented. Respectively, these cases highlight the utility of detailed petroleum fingerprinting of the diagnostic (1) volatile hydrocarbons comprising gasoline(s) and (2) non-volatile hydrocarbons, including petroleum biomarkers and an extended suite of parent and alkylated polycyclic aromatic hydrocarbons, found in crude oil(s) (and other heavy petroleum products). 相似文献
19.
非饱和土水力学参数包括土-水特征曲线和渗透函数是非饱和土研究的重要内容。鉴于传统的测试方法耗时较长,提出了能够快速测定非饱和土水力学参数的一步流动方法和动态多步流动方法,并利用联合测试系统分别开展流动试验。通过对比分析,这两种方法得到的试样平衡态土-水特征曲线均与实测值接近,并且有效地避免了由于测试时间较长高压气体通过水流在陶土板背面析出的问题。一步流动方法比动态多步流动方法需要的时间短,但反算得到的土-水特征曲线与实测值的接近程度不如动态多步流动方法,因此,动态多步流动方法要优于一步流动方法。 相似文献
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土水特征曲线的通用数学模型研究 总被引：13，自引：3，他引：13
土水特征曲线对于研究非饱和土的物理力学特性至关重要。根据土水特征曲线可以确定非饱和土的强度、体应变和渗透系数 ,甚至可以确定地下水面以上水份分布。由于土体物理力学特性的差异 ,导致描述其土水特征曲线的数学模型也各不相同。因此 ,建立土水特征曲线的通用数学表达式 ,显得尤为必要。本文对土水特征曲线数学模型进行了研究 ,依据这些模型的数学表达式形式 ,将其划分为 4种类型。分别由这 4种类型的数学模型推导出具有统一表达式形式的土水特征曲线通用数学模型 ,并运用陕北高原黄土土水特征曲线试验数据对通用数学模型进行了研究 相似文献