浑河河水及其沿岸地下水污染特征

选择沈阳地区重要河流浑河及其沿岸地下水进行定量分析,研究并探讨了包括无机物和有机物在内的水质综合污染特征。结果表明,浑河河水中氨氮、硝氮、亚硝氮和酚超过了地表水环境质量标准,最大超标倍数分别为15.8、1.5、82.4和1.8倍,检测出的11种卤代烃、氯苯和六六六等有机物均未超标。浑河沿岸地下水中氨氮、硝氮、亚硝氮、化学需氧量、酚和铅超过地下水质量标准,超标率分别为31.6%、10.5%、26.3%、36.8%、47.4%和26.8%,检测出的4种卤代烃和六六六等有机物均未超标。河水及其沿岸地下水中的污染物,尤其是有机污染物种类和浓度高值基本出现在城西的谟家—大祝断面之间。浑河水质主要受城市工业废水、居民生活污水排放的影响,沿岸地下水的污染来源包括工业生产或农村居民生活造成的地表污染物垂直入渗式的点源污染、浑河水侧向渗透补给式的线源污染以及农药化肥使用产生的面源污染,而有机污染物主要通过点源污染地下水。浑河各区段的使用功能、包气带岩性及沿岸水源地开采井布局等因素都为受污染的河水对沿岸几百米范围内的浅层地下水的补给提供了条件,造成浅层地下水的污染,对当地生态系统及人类健康构成潜在威胁。     

沈阳细河水中多环芳烃的分布、来源及生态风险评价

通过测定不同季节细河水中多环芳烃(PAHs)的含量,研究了细河水中PAHs的分布,探讨了PAHs的来源,评价了其生态风险。细河水中6月(夏季)16种PAHs的含量为0.214～0.857μg·L-1,平均为0.562μg·L-1;9月(秋季)水中PAHs含量为0.195～0.633μg·L-1,平均0.380μg·L-1;11月(冬季)水中PAHs含量为0.122～0.486μg.L-1,平均含量为0.236μg·L-1。苯并(a)芘含量明显高于国家地表水环境质量标准(GB3838-2002);对细河水中PAHs污染来源分析发现,6月和9月PAHs的主要来源为石油污染和石油及其精炼产品的燃烧;通过商值法对细河的初步风险评价表明,细河水中苯并(a)芘存在较大的生态风险,应引起关注。     

城市地表径流污染来源的分类与特征

城市地表径流中污染物的分布和浓度等污染特征取决于其污染来源。本文依据3种分类方法分析了城市地表径流污染物的来源及其特征,重点讨论了城市地表径流中主要的污染物悬浮颗粒物、持久性有机污染物、农药、重金属、营养元素、有机质和其他有代表性的工业源化合物的来源、污染特征和生态风险等,介绍了城市地表径流对受纳水体的影响及其评价方法,并探讨了今后的研究重点。     

滩涂底栖动物有机污染生态学研究进展

底栖动物由于对有机污染物具有较强的吸收能力,再加上其移动能力较差、生活方式比较固定,而被广泛运用于滩涂有机污染的研究.目前这些研究主要集中在如下几个方面：（1）有机污染物在底栖动物体内的分布特征及在底栖食物链中的动力学研究;（2）底栖动物对有机污染物的生理响应研究;（3）污染物对底栖动物群落组成和结构影响研究;（4）底栖动物在滩涂有机污染检测中的应用研究.研究结果表明：滩涂底栖动物对有机污染物的累积具有选择性和季节波动性;有机污染物可以在底栖食物链中传递;底栖动物体内的有机污染物成分和含量可以有效地指示其生存环境的有机污染状况;底栖动物的混合功能氧化酶和抗氧化酶系统对体内有机污染物的累积产生积极的响应;有机污染物对底栖动物的免疫系统造成不利影响,并对遗传物质造成破坏;有机污染对底栖动物的群落组成和结构具有显著的影响.     

污染土壤中多环芳烃的共代谢降解过程

1　前　言多环芳烃是一类普遍存在于环境中的重要有机污染物 ,因其致癌性、致畸性、致突变性而被认为是危险物质。由于其水溶性低 ,辛醇 水分配系数高 ,因此 ,该类化合物易于从水中分配到生物体内、沉积层中。土壤成为多环芳烃的重要载体 ,多环芳烃污染土壤的生物修复也因此倍受关注。多环芳烃在土壤中有较高的稳定性 ,其苯环数与其生物可降解性明显呈负相关关系。很少有能直接降解高环数多环芳烃的微生物。研究表明 ,高分子量的多环芳烃的生物降解一般均以共代谢方式开始[1 3] 。共代谢作用可以提高微生物降解多环芳烃的效率 ,改变微生物碳…     

我国农业土壤及农作物中多环芳烃污染特征与来源

为准确评估我国农田区域环境状况,以多环芳烃(PAHs)为研究对象,收集并整理近十年的农业土壤及农作物PAHs污染调查结果,基于此,系统分析我国农业土壤及农作物中PAHs的含量、组成、分布特征及来源.结果表明:我国大部分农业土壤PAHs污染为中低污染水平,残留值为0～40300.0μg/kg,中位值为499.2μg/kg...     

菲污染土壤的微生物修复机制

菲(Phenanthrene)是存在于煤焦油中,含三个苯环的稠环芳烃。除了具有\"三致\"作用外,菲稳定的化学结构和高辛醇-水分配系数等特性,使其具备较强的抗降解能力,易在环境中富集,破坏土壤微生态结构,降低农作物品质,威胁人类健康。而且随着化石燃料的长期大量使用,受菲污染的土地面积也急速增加,给人类的健康及生产活动带来极大的威胁。因此,有效清除土壤中菲及其他多环芳烃污染物,净化环境,具有重要的现实意义。微生物降解作为治理菲污染的方法之一,具有高效、低成本、环境友好的特点,受到研究者的高度重视。本文从菲降解菌的种类、降解机理、分子机制、影响修复等因素及微生物与植物联合修复五个方面进行综述,为进一步利用环境微生物,开发高效菲降解菌,治理菲污染提供参考。     

河水高浓度有机污染降解菌分离、鉴定及降解特性

为了恢复遭受严重有机污染北方季节性河流自净能力,以河北某典型黑臭河流为研究对象,采集其河道底泥和水样,采用乳酸菌、酵母菌、放线菌和硝化细菌专性培养基对底泥中的微生物进行富集、分离、纯化,获取了15株有机污染物降解菌,对其中的6株优势菌采用脂肪酸谱图分析进行了鉴定,这6株菌最终鉴定为黄杆菌属(Flavobacterium)、微球菌属(Micrococcus)、乳杆菌属(Lactobacillus)、小单孢菌属(Micromonospora)、假丝酵母菌(Candida)、硝化球菌属(Nitrococcus).为了提高菌株的降解与适应能力,采用定向富集液进行菌群复配,得到复合菌,复配试验表明,菌群最佳配比为乳酸菌1.0％、酵母菌0.5％、放线菌2.0％、硝化细菌2.0％.复合菌培养研究发现,复合菌最佳生长条件为pH 7.0,温度35℃,以葡萄糖为最佳碳源、需要少量Fe2+、Mg2+、Ca2+等无机盐.污染物降解试验表明,当pH、温度、菌量、转速分别为8、35℃、0.5％、80 r·min-1时,复合菌对污染物的降解效果最好,CODcr、NH3-N和TP去除率分别达到78％、59％和77％.     

持久性有机污染土壤的植物修复及其机理研究进展

随着人类对化学品的依赖程度越来越高,环境的有机污染状况也越来越严重.有机污染土壤的植物修复是指利用植物在生长过程中,吸收、降解、钝化有机污染物的一种原位处理污染土壤的方法,具有应用成本低、生态风险小、对环境副作用小等特点.本文综述了近年来国内外有机污染土壤的植物修复研究进展情况,重点介绍了多氯联苯、多环芳烃、农药和硝基芳香化合物等持久性有机污染物的植物修复,阐述了有机污染土壤植物修复的关键机制,并分析了该技术在实际工程应用中的局限性及应考虑的因素.最后,指出了今后该领域的重点研究方向.     

植物-固定化菌剂联合修复多环芳烃污染土壤

以火凤凰根际土壤中发现的3种优势菌[分枝杆菌(Ⅰ)、产黄纤维单胞菌(Ⅱ)、少动鞘氨醇单胞菌(Ⅲ)]构建的多菌剂体系为供试菌剂,针对大港油田原油污染土壤,将固定化供试菌剂接种于修复植物火凤凰根际,探讨供试菌剂强化火凤凰修复多环芳烃(PAHs)污染土壤的效果.结果 表明:处理ⅠⅢ(有效活茵数为109 cfu·mL-1)和Ⅰ...     

The use of hydrocarbon analyses for environmental assessment and remediation

Battelle Ocean Sciences has developed an analytical approach to identify and’ quantify petroleum products, coal products, and individual hydrocarbon components at trace levels in complex environmental matrices. The hydrocarbon analysis strategy uses capillary gas chromatography/flame ionization detection for alkane and total oil analysis, combined with gas chromatography/mass spectrometry for polynuclear aromatic hydrocarbon analysis. The method provides environmentally realistic analyte detection limits (parts per trillion in water, parts per billion in sediments) and an analyte list that is designed specifically for petroleum and coal‐based products. Results are compared to a detailed computerized library of total, water‐soluble, and degraded hydrocarbon products. The systematic data interpretation strategy maximizes the accuracy of petroleum and coal product identification in environmental matrices and represents a vast improvement over standard EPA methodology.     

Biodegradation of Hopane Prevents Use as Conservative Biomarker During Bioremediation of PAHs in Petroleum Contaminated Soils

The pentacyclic triterpane C₃₀ 17α (H), 21β (H)-hopane, a biomarker commonly used in hydrocarbon bioremediation laboratory experiments and field studies, was found to be completely removed without the formation of the demethylated intermediate nor-hopane in a crude oil-contaminated soil undergoing slurry biotreatment, while PAHs such as benzo(e)pyrene were recalcitrant. The partial or complete biodegradation of hopane has also been previously reported in a few bioremediation studies and has been explored by petroleum geochemists in an effort to characterize crude oil deposits. It is currently not clear what conditions induce hopane biodegradation or biotransformation, although the use of microbial enrichment cultures appears to speed up the process. Considering that hopane is not necessarily conserved during a bioremediation study, the uncritical normalization of hydrocarbon concentrations using this biomarker can lead to incorrect estimates of biodegradation rates and extents. If hopane is found to be unstable in a particular case, other potential biomarkers such as pentahopane, oleanane, or vanadium may be used instead.     

Assessment of Polycyclic Aromatic Hydrocarbons (PAH) and Heavy Metals in the Vicinity of an Oil Refinery in India

Petroleum products are one of the major sources of energy for industry and daily life. Growth of the petroleum industry and shipping of petroleum products has resulted in the pollution. Populations living in the vicinity of oil refinery waste sites may be at greater risk of potential exposure to polycyclic aromatic hydrocarbons (PAH) through inhalation, ingestion, and direct contact with contaminated media. PAH have often been found to coexist with environmental pollutants including heavy metals due to similar pollution sources. The levels and distribution patterns of Σ16 PAH (sum of the 16 PAH) and heavy metals (lead, copper, nickel, cobalt, and chromium) were determined in soil and sediment in the vicinity (5 km radius) of an oil refinery in India. Concentrations of Σ16 PAH in the soils and sediments were found to be 60.36 and 241.23 ppm, respectively. Higher amount of PAH in sediments as compared to soil is due to low water solubility of PAH, settled in the bottom of aquatic bodies. The levels of lead, copper, nickel, cobalt, and chromium (total) in soil were 12.52, 13.52, 18.78, 4.84, and 8.29 ppm, while the concentrations of these metals in sediments were 16.38, 47.88, 50.15, 7.07, and 13.25 ppm, respectively. Molecular diagnostics indices of PAH (Ratio of Phenanthrene/Anthracene, Fluranthene/Pyrene) calculated for soil and sediment samples indicate that the oil refinery environment is contaminated with PAH from petrogenic as well as pyrolytic origin and heavy vehicular traffic on the Agra- Delhi National highway. Sixteen PAH priority pollutants were detected in the United States in entire samples collected near oil refinery areas and concentrations of Σ16 PAH in soil was found to be 1.20 times higher than the threshold value for PAH in soil by ICRCL (Inter-Departmental Committee on the Redevelopment of Contaminated Land). This concentration could lead to disastrous consequences for the biotic and abiotic components of the ecosystem and may affect the soil quality, thus impairing plant growth and its bioaccumulation in food chain.     

Case Study of Petroleum Contaminated Area of Novi Sad After NATO Bombing in Yugoslavia

The 1999 NATO bombing of the oil refinery in Novi Sad (Yugoslavia) has heavily contaminated the Danube River and its sediments, as well as the surrounding soil and groundwater. The destruction of the factories released 73,569 tons of crude oil of which 90% was incinerated, 560 tons reached the Danube River, and the remainder was spilled onto the soil. The contents of oil and oil derivatives in the soil were in the range of 3 to 42,000?mg/kg. The first soil layer contained an average of 67,000?mg/kg of crude oil and oil derivatives. The layers beneath it, above the groundwater table, contained 56?ml/l of free oil derivatives in the drained water. The spreading of this pollution could imperil the groundwater quality in the water supply zone because the refinery is located in the hinterland of the zone. The quality of water and sediment samples was monitored from April 1999 to November 2000 by measuring concentrations of hydrocarbons and polyaromatic hydrocarbons (PAH). The hydrocarbon content in the Danube River water in October 2000 was about 20% of the value measured at the time of the accident. Immediately after the accident the concentration of mineral oil in the surface sediment was in the range of 0.11 to 0.29?g/kg. At the same time PAH concentrations in the river sediment were up to 160?mg/kg, depending on the sampling site location. The values showed a decrease in the course of further monitoring.     

The effect of soil‐particle size on hydrocarbon entrapment near a dynamic water table

The entrapment of residual hydrocarbon globules by water table fluctuations can produce a long‐term contamination threat to groundwater supplies that is difficult to remove. The mobilization of entrapped hydrocarbon globules depends on the balance between capillary and gravitational forces represented by the Bond number. It is important to estimate the potential for hydrocarbon entrapment at a spill site due to its influence on the effectiveness of remediation efforts. The present work focuses on the influence of particle diameter on hydrocarbon entrapment for a typical LNAPL (light nonaqueous‐phase liquid). Laboratory column tests have been conducted using a dual‐beam gamma densitometer to measure saturations of the three phases (water, air, and hydrocarbon). Soltrol 170^®, a solvent manufactured by Phillips 66 Co., is used as the hydrocarbon. Residual saturation of the Soltrol is measured after fluctuations in water table level to establish the distribution and consistency of hydrocarbon entrapment below the water table. Glass particles of nearly uniform size were used to represent a sandy soil. In the experiments, average particle sizes ranged from 210 to 6000 μm. Data were also taken using the synthetic soil matrix approved by the U.S. Environmental Protection Agency (EPA) for contamination studies. Results show that the distribution of trapped LNAPL is quite uniform and that the average residual saturation is about 13% up to a particle diameter of 710 μm. Above this diameter, residual saturation decreases with particle size. The corresponding critical Bond number, determined experimentally, agrees well with the predicted value of 1.6.     

Petroleum bioremediation — a multiphase problem

Microbial degradation of hydrocarbons is a multiphase reaction, involving oxygen gas, water-insoluble hydrocarbons, water, dissolved salts and microorganisms. The fact that the first step in hydrocarbon catabolism involves a membrane-bound oxygenase makes it essential for microorganisms to come into direct contact with the hydrocarbon substrate. Growth then proceeds on the hydrocarbon/water interface. Bacteria have developed two general strategies for enhancing contact with water-insoluble hydrocarbons: specific adhesion mechanisms and production of extracellular emulsifying agents. Since petroleum is a complex mixture of many different classes of hydrocarbons, of which any particular microorganism has the potential to degrade only part, it follows that the microorganisms must also have a mechanism for desorbing from used' oil droplets.The major limitations in bioremediation of hydrocarbon-contaminated water and soil is available sources of nitrogen and phosphorus. The usual sources of these materials, e.g. ammonium sulfate and phosphate salts, have a high water solubility which reduces their effectiveness in open systems because of rapid dilution. We have attempted to overcome this problem by the use of a new controlled-release, hydrophobic fertilizer, F-1, which is a modified urea-formaldehyde polymer containing 18% N and 10% P as P₂O₅. Microorganisms were obtained by enrichment culture that could grow on crude oil as the carbon and energy source and F-1 as the nitrogen and phosphorus source. The microorganisms and the F-1 adhered to the oil/water interface, as observed microscopically and by the fact that degradation proceeded even when the water phase was removed and replaced seven times with unsupplemented water — a simulated open system. Strains which can use F-1 contain a cell-bound, inducible enzyme which depolymerizes F-1.After optimizing conditions in the laboratory for the use of F-1 and the selected bacteria for degrading crude oil, a field trial was performed on an oil contaminated sandy beach between Haifa and Acre, Israel, in the summer of 1992. The sand was treated with 5 g F-1 per kg sand and inoculated with the selected bacteria; the plot was watered with sea water and plowed daily. After 28 days the average hydrocarbon content of the sand decreased from 5.1 mg per g sand to 0.6 mg per g sand. Overall, there was an approx. 86% degradation of pentane extractables as demonstrated by dry weight, I.R. and GLC analyses. An untreated control plot showed only a 15% decrease in hydrocarbons. During the winter of 1992, the entire beach (approx. 200 tons of crude oil) was cleaned using the F-1 bacteria technology. The rate of degradation was 0.06 mg g^-1 sand day^-1 (10°C) compared to 0.13 mg g^-1 sand day^-1 during the summer (25°C).     

石油污染环境中固氮和寡氮营养细菌的分离鉴定及其特性

[背景]石油污染治理中的生物修复因无二次污染、处理成本低等优点受到人们的广泛关注,但由于石油烃向环境中大量输入,导致环境中氮源的相对不足成为制约生物修复效率的关键因素之一,因此筛选能够适应寡氮环境的微生物具有重要的生态意义.[目的]从辽河油田油藏水中筛选在不添加氮源培养基中生长的微生物,为石油污染环境生物修复提供候选菌...     

The effect of interfacial tension on hydrocarbon entrapment and mobilization near a dynamic water table

The entrapment of residual hydrocarbon ganglia during water table fluctuations can produce a long‐term contamination threat to groundwater supplies that is difficult to remove. The mobilization of entrapped hydrocarbon ganglia depends on the balance between capillary and gravitational forces represented by the Bond number. The present work focuses on the influence of the interfacial tension between the hydrocarbon and the surrounding water on the entrapment and mobilization of the residual ganglia. Laboratory column tests using glass beads as the porous medium have been conducted to determine the residual saturation of a hydrocarbon (Soltrol 170) trapped during vertical displacements due to a rising water table and the necessary decrease in interfacial tension to mobilize these trapped ganglia. The interfacial tension was decreased by the addition of isopropyl alcohol to the water phase. Saturations of the three phases (water, hydrocarbon, and air) were measured with a dual‐beam y‐densitometer. The results for residual hydrocarbon saturation at various interfacial tensions were combined with previous results for different particle diameters to provide a general relationship between residual saturation and Bond number. The relationship is expressed in an empirical correlation valid for Bond numbers between 0.001 and 1.2.