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.     

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。     

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。     

秸秆与微生物协同修复石油污染土壤

选择小麦秸秆协同Alcaligenes spJ 1和 Arthrobacter spJ 2混合菌进行石油污染土壤修复,研究秸秆与微生物协同修复石油污染土壤的效果。设计腐解实验,考察秸秆腐解对微生物吸附的影响;设置秸秆固定化微生物（IMM）、秸秆 游离菌（STM）2组修复实验,以游离菌（CP）为对照,考察秸秆、微生物的2种协同修复方式IMM、STM对石油污染土壤修复效果的不同和秸秆腐解的差异。结果表明,随着秸秆腐解程度的加剧,秸秆对微生物的吸附性能变差,可能与腐解过程秸秆的结构变松散有关;IMM组石油烃降解率较高,秸秆腐解较快,比STM组石油烃降解率高10%,腐殖酸质量分数多30 g/kg;石油烃降解率与腐殖酸含量的相关关系比较显著,相关系数为0906;IMM对土壤的修复效果更好。     

克拉玛依石油污染土壤生物修复的初步研究

进行了克拉玛依石油污染土壤生物模拟修复实验,考察了最佳启动条件,分析了在生物修复过程中土壤理化性质、微生物学特性、石油烃组分的变化。实验结果表明,影响生物修复效果的主要因子为菌剂的投加量、水分含量以及鸡粪投加量;最佳启动条件为每1kg污染土壤菌剂投加量200mL,水分含量15%,鸡粪投加量120g,麦糠投加量50g,表面活性剂30mL,经75d修复后石油烃的降解率达到了56.31%;生物修复的不同阶段土壤理化性质和微生物学特性有较大变化,修复过程土壤脲酶、脱氢酶活性降低,过氧化氢酶活性升高。石油烃四组分分离和模拟蒸馏实验表明,微生物对石油烃中四组分的降解能力大小依次为饱和分,芳得分,胶质和沥青质;在生物修复过程中,微生物优先利用低碳数的正构烷烃,经过70d的降解,C₁₂~C₁₄含量低于检测限;正构烷烃色谱峰型发生较大变化,由左右对称变为“左缓右陡”;异构烷烃相对含量增加,色谱基线被明显抬高。     

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。     

Bioremediation of Petroleum contaminated soils collected all around China: The extensive application and the microbial mechanism

A commercial microbial agent (Devoroil) was applied to study the biodegradation efficiency of four petroleum contaminated soils/sediment collected all around China. After 40 days of biodegradation, the total petroleum hydrocarbons removal rates were 41.8%, 95.7%, 84.5% and 93.5%. The soil achieved the lowest biodegradation efficiency was chosen to conduct another bioremediation experiment to study the degradation dynamics of petroleum and the microbial mechanism. The results showed that biodegradation dynamics correspond to a negative index relation. The analysis of PCR-DGGE exhibited that Thioalkalivibrio sp., Nocardia sp. and Mycobacterium sp. were probably the dominant functional microbes in the contaminated environment.     

紫花苜蓿-铜绿假单胞菌联合修复石油污染土壤

选择紫花苜蓿协同铜绿假单胞菌进行石油污染土壤修复,探究植物-微生物联合修复石油污染土壤的效果及作用机理,并考察了石油初始含量、植株种植密度、菌剂投加量及营养物对紫花苜蓿-铜绿假单胞菌联合修复效果的影响。结果显示,紫花苜蓿-铜绿假单胞菌联合修复效果明显优于单一紫花苜蓿或铜绿假单胞菌修复,经过56 d的修复,土壤中石油的去除率高达72%。在联合修复体系中,植物与微生物表现出明显的互生作用。当污染土壤中石油初始质量分数为0.6%,紫花苜蓿种植密度为20棵/dm²,土壤中铜绿假单胞菌菌剂投加量为20 g/kg时,污染土壤的修复效果最佳且修复体系能够得以充分利用。适量的氮、磷营养物添加可进一步改善紫花苜蓿-铜绿假单胞菌联合修复效果。     

地下水封储油洞库渗流及油品储存试验研究

文章以实际地下水封石油洞库为原型,在室内构建了花岗岩的洞库模型,以等比例缩尺设计了水平裂隙和倾斜裂隙,并开展了渗漏、油品储存试验。对比了裂隙渗透系数的立方定律计算值和达西定理计算值,发现达西定理计算值只有立方定律计算值的15%左右。观察与计算了油水界面的变化规律及渗流场的运动规律,得出:连通器原理可用于计算地下水水位提升时的油水界面,地下水位小幅度下降时水垫层排水有助于保持洞室内储油的稳定。     

在役油气管道土壤腐蚀研究现状

油气输送管道在运行过程中,由于防腐层破损,管道将受到土壤的腐蚀作用,从而导致腐蚀穿孔事故的发生。开展管道土壤腐蚀速率测试和腐蚀寿命预测方法研究,对于保障油气管道的安全运行,避免管道失效事故的发生具有重要的工程实用价值。文章综述了国内外对在役管道土壤腐蚀速率测试方法、土壤腐蚀速率模型建立和土壤腐蚀剩余寿命预测方法等方面的研究成果。     

在用柴油机油基础油及其中的清净分散剂耗解研究

应用理化检测及元素分析、红外光谱、气相色谱和质谱等分析技术对在用柴油机油基础油及其中的金属清净剂的耗解进行了跟踪分析。结果表明,在用柴油机油基础油在使用过程中,黏度、密度等理化指标发生显著的变化,其中金属清净剂的耗解水平可以通过油品碱值或添加剂的特征红外光谱来表征。     

Desulfurization of Diesel Fuel in a Fixed Bed Adsorption Column: Experimental Study and Simulation

Abstract

Desulfurization of diesel fuel was investigated in a fixed bed adsorption column using activated carbon as an adsorbent. The experiments were carried out at different feed flow rates, bed depths, and temperatures, and each experiment resulted in at least one sample containing less than 10 mg/kg of sulfur. Experimental data were used to simulate/predict the dimensions of an adsorption column for potential industrial application of adsorptive desulfurization of diesel fuel. The calculation resulted with a height of adsorption column of 17.32 m and an adsorbent load of 93.5 tons. The calculated column height is within the limits for a typical industrial adsorption column.     

甜菜碱/聚合物二元体系驱油性能研究

在模拟大庆油田条件下测定了0.5、1.5、2.5 g/L聚合物污水溶液的黏度、储能模量G＇和损耗模量G″,由G＇和G″按文献公式计算了溶液的第一法向应力差N1;用以表征黏弹性溶液的弹性时,频率10 Hz下的N1值比G＇值要明锐些。用聚合物浓度0、0.5、1.5、2.5 g/L,表面活性剂（磺基甜菜碱BS）浓度0～0.3...     

坨11区块泡沫驱油的室内研究与现场实践

胜利油田坨11区块稠油油藏水驱开发已进入高含水期。油藏地温~60℃,平均渗透率~1.5μm2,地层水矿化度12.4 g/L,含Ca2 M2 580 mg/L。筛选出了发泡剂DP-4,其5 g/L溶液形成的氮气泡沫表观粘度μa=789.5 mPa.s,阻力系数FR=1579,残余阻力系数FRR=186,加入聚合物HPAM(0.5~2.5 g/L)对μa和FR影响不大,但使FRR急剧增至488.5~737.0。气液比为1∶1和2∶1时聚合物复合氮气泡沫的FR均在1500以上,表明该泡沫体系有强封堵能力;FR随渗透率增大(0.7~10μm2)由1100增至4200,表明该泡沫体系的封堵具有渗透率选择性。在油饱和人造岩心上,在水驱之后注入DP-4/HPAM氮气泡沫使采收率由54%提高至79%。在坨11北区1口油井注入DP-4/HPAM(10~5/2.0~1.8 g/L)氮气泡沫,气液比1∶1,共注入地面氮气6.044×105m3,DP-434.75 t,HPAM 1.1t,周围4口同层位油井平均含水由71.5%降至44.7%,15个月增产油12072 t,减产水6445m3,且仍处于增产有效期。图4表2参2。     

A Laboratory Study of Recovery with Carbon Dioxide around Critical Conditions of Trinidad's Heavy Oil and Tar Sands

Abstract

VAPEX is a heavy oil recovery process where two horizontal wells are placed low in a reservoir and solvents passed into the reservoir via the higher of the two wells. This lowers the oil viscosity and allows the oil–solvent mixture to move to the lower well. CO₂ could be a suitable solvent.

Some experimental work on heavy oil recovery using CO₂ at points around its critical conditions of 31°C and 73.3 bar is presented here. The recovery was between 15 to 30% with most of the extracts lying in the range above C₁₂. Reservoirs deeper than 2500 ft are therefore suited to this type of process.     

A Comparison of Normal and Reversed Phase Columns in Oil Analysis by Comprehensive Two-dimensional Gas Chromatography With Time-of-flight Mass Spectrometry

Four typical crude oil samples collected from the Junggar Basin of northwest China were analyzed by comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS) under different experimental conditions, which include normal phase column system (nonpolar × polar) and reversed phase column system (polar × nonpolar). A comparative study was conducted on the general chromatogram features, and chromatogram features of saturate and aromatic hydrocarbons. Analytical results show that the normal phase (NP) column system has higher resolution for the identification of high molecular weight polycyoalkanes and polycyclic aromatic hydrocarbons, while the reverse phase (RP) column system has higher separation on the saturate hydrocarbons, especially on medium-low molecular weight iso-alkanes and cycloalkanes. In addition, the RP system can also meet the separation requirements of aromatic compounds, by the extraction of diverse organic compounds by characteristic ions. Therefore, the RP system has special advantages in the analysis of medium-low molecular weight hydrocarbon compounds in crude oil, and can be applied more widely in the future besides the presently common use of the NP system.     

四川盆地中国石化探区油气勘探历程与启示

在系统梳理四川盆地中国石化探区石油地质理论、勘探成果的基础上,通过对四川盆地勘探历程回顾,将其勘探历程划分为构造油气藏勘探（1953—2000年）、岩性气藏勘探（2000—2010年）、常规与非常规油气藏勘探（2010年至今）3个勘探阶段。优选近20年来中国石化在四川盆地最具有代表性的普光气田、元坝气田和涪陵气田3个大气田,通过梳理其早期勘探面临的主要问题、理论认识创新、勘探思路转变、勘探发现与后续部署的系统论述,以期为其他盆地或地区勘探工作提供借鉴。     

A Simulation Study of Carbon Dioxide Sequestration in a Depleted Oil Reservoir

Abstract

Oil fields offer significant potential for storing carbon dioxide (CO₂) and will most likely be the first large-scale geological targets for sequestration because the infrastructure, experience, and permitting procedures already exist. In addition, almost 40 years' experience in enhanced oil recovery (EOR) allows utilization of carbon capture and storage (CCS) and CO₂ sequestration techniques in such a way as to improve recovery of petroleum fields and reduce the environmental issue of fossil fuel combustion gas products, particularly carbon dioxide. Carbon dioxide is one of the main greenhouse gases that causes global warming.

As a response to global warming, geologic sequestration of CO₂ in oil and gas reservoirs is one possibility to reduce the amount of CO₂ released to the atmosphere. This simulation study presents a synthetic geologic model that is used to sequestrate carbon dioxide beside an EOR immiscible displacement process.     

In situ bioremediation of crude oil contaminated site: A case study in Jianghan oil field,China

A bacterial consortium, constructed from the oil contaminated soil, mainly consisting of Pseudomonas sp., together with fertilizing, rice husk application, and plowing, was used for the field in situ bioremediation of oil contaminated site in Jianghan Oil field, where the temperature and humidity are very suitable for bioremediation. The variation of total petroleum hydrocarbon, n-alkanes, and polycyclic aromatic hydrocarbons (PAHs) in the bioremediation process showed that more than 95% petroleum hydrocarbons could be efficiently removed. The composition analysis results demonstrated that n-alkanes with long carbon chain and PAHs with 5–6 rings were also degraded in the bioremediation process.     

Microscopic Study of Oil Flocculation and Coalescence Processes for Understanding the Role of Surfactants in EOR Performance

Abstract

A preliminary microscopic study of oil/oil droplet interactions in surfactant-added water is carried out to understand the oil/water interface changes with time and its effects on oil/oil droplet coalescence. This study is carried out on two oils (olive and crude oil) with varying concentrations of surfactant water ratios. The radii of curvature of the interface between coalescing oil droplets is used as a measure to reflect the change in surface energy. As oil droplets were placed in surfactant-added water, the radii of curvature were measured at three different states. Early state shows very little effect on oil/oil interfaces; in the later state, the effect is greater and interfacial tension decreases rapidly. At quasi-steady state, the state between the early and later, faster rate stage reduces with surfactant concentration in the case of olive oil. Increasing the surfactant concentration does not show the same effect on crude oil. The radii of curvature increase with time by increasing surfactant concentrations in olive oil; an inverse effect is found in crude oil. A natural surfactant prepared from the outer shell of pericarp of soapnut fruit was also used to study droplet formation and coalescence as well as to investigate the impact in interfacial tension and oil mobility.