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1.
科学合理的地下水污染修复技术筛选方法对于有效修复受污染地下水体、节约修复工程成本、保护地下水资源、维护生态系统安全和人体健康具有重要意义。以某化工厂遗址早期排污渗坑为目标污染源,在结合水文地质勘查和地下水人体健康风险评价的基础上确定场地受污染地下水修复目标污染物,根据污染物迁移性、降解性、人体健康风险等指标及抽出处理、化学修复、生物修复、渗透反应格栅等地下水污染修复技术特点,使用偏好顺序结构评估法(PROMETHEE)进行修复技术筛选。结果显示,该场地地下水中主要污染物为1,2-二氯乙烷、1,4-二氯苯等有机污染物,其中1,2-二氯乙烷在呼吸吸入条件下的最大致癌风险达9.54×10-7。化学清除、监测自然衰减等四项技术适用于该场地地下水1,2-二氯乙烷修复,化学清除法综合排序分值最高,而在成本优先控制条件下,监测自然衰减技术更为适宜。研究对于我国场地地下水污染调查评估及修复工作具有积极的参考意义。  相似文献   

2.
为了解典型污染场地浅层地下水微量有机污染特征,对西北某省会城市石油化工场地地下水中的挥发性有机污染物(VOCs)污染情况进行了调查。结果表明,污染场地地下水样品中挥发性有机污染物检出率为100%;检出率较高的是氯代烃和苯系物,检出率分别为60%和40%。超标组分为苯和1,2-二氯丙烷,苯超标率为30%,1,2-二氯丙烷超标率10%,苯最大检出浓度达1515μg/L。场地内的原油储存罐、污水隔油池的渗漏以及石油冶炼、机械加工过程工业废水不合理排放均为该场地地下水VOCs的重要来源;VOCs的理化性质以及污染场地地下水防污性能差是影响该场地地下水环境中VOCs归宿的主要因素。  相似文献   

3.
1,2-二氯乙烷(1,2-DCA)和1,2-二氯丙烷(1,2-DCP)是某污染场地地下水中检出最高的挥发性有机污染物。文中采用批试验方法,研究污染场地包气带中三种不同深度土壤样品对1,2-DCA和1,2-DCP的吸附-解吸特性。结果表明:土壤中有机质决定其吸附行为,三种土壤对1,2-DCA和1,2-DCP的吸附符合Henry线性等温方程,分配系数在20.49~22.43L.kg-1,1,2-DCA和1,2-DCP在三种土壤中分别具有相似的吸附能力;同一土壤中两种目标污染物的吸附能力为Kd(1,2-DCA)>Kd(1,2-DCP),但差别不大。1,2-DCA和1,2-DCP在三种土壤中的解吸可用Freundlich等温方程拟合,解吸的难易程度与土壤中黏粒含量相关,黏粒含量越高,目标污染物的解吸越困难,第三层(地下4.9~5.1m)土壤的防污能力较强;两种污染物在三种土壤中的解吸都存在明显的滞后效应,1,2-DCP的滞后指数比1,2-DCA的大。  相似文献   

4.
为查明华北平原某油田采油井密集区的采油场地、输油管线对地下水、土壤污染程度、分布特征,依据《地下水污染调查评价规范》(DD2008-01)要求,在9个场地采集采集9个水样、31组土样,进行有机组分指标测试。结果表明,地下水样品中,有4个检出石油烃,检出率为50%,检出含量120~1 661μg/L,有2个样品含量大于300μg/L(《生活饮用水卫生标准》GB 5749—2006石油烃标准);有5个样品检出其他有机污染组分,为苯、甲苯和苯并[a]芘,均为芳烃类,检出的含量较低,多为目标检出限的1~5倍。采油井周围土壤中石油烃检出含量较高,检出含量多高于万分之一以上,采用重量法百分比表达;在同一场地内不同地点、不同深度土壤石油烃含量极不均匀,具有很大的不确定性;输油管道穿孔对土壤污染严重,输油管(1 m以下)附近土壤颜色变黑,石油烃检出含量高达4.19%;石油开采已经对采油场地附近农田造成污染,某处农田地表(0~0.2 m)处检出石油烃含量为266 mg/kg。初步认为,评价区内地下水石油烃污染主要是采油场地原生态的破坏和事故性污染造成。  相似文献   

5.
根据U.S.EPA的健康风险评价模型,笔者评价了某废弃化工场地对人体的健康风险,结果表明:1)该场地地下水的典型有机污染物为1,2-二氯丙烷、苯、甲苯、三氯甲烷;2)对于非致癌风险和致癌风险,3种暴露途径的健康风险顺序均为:呼吸途径>饮水途径>皮肤接触途径;3)非致癌风险中3个点超过规定限值1.0,致癌风险中4个点均超过规定限值10-6,是不可接受的。保持居住环境内空气畅通,可以在一定程度上降低健康风险。  相似文献   

6.
以典型纳污坑塘(污水库)周边地下水水质监测数据为基础,在对区内地下水污染源进行分析的基础上,采用水环境健康风险评估模型,对区内地下水污染健康风险进行了系统评价研究。污染来源识别结果表明:纳污坑塘周边第Ⅰ、第Ⅱ含水层地下水污染严重,其污染源主要为坑塘内堆放的工业污水以及工业废渣。污染健康风险评估结果表明:8号坑附近第Ⅰ含水层中砷浓度以及北库南侧第Ⅱ含水层中1,2-二氯乙烷总致癌风险分别为10~(-2)、10~(-3)数量级,远超可接受风险水平10~(-6)。不同含水层中污染物平均致癌风险大小关系为,第Ⅰ含水层:砷1,2-二氯乙烷;第Ⅱ含水层:1,2-二氯乙烷砷1,1,2-三氯乙烷四氯化碳。1,2-二氯乙烷等挥发性有机污染物4种潜在暴露途径的平均致癌风险大小关系表现为:饮用地下水皮肤接触地下水经室外吸入空气中气态污染物经室内吸入空气气态污染物。相对于敏感用地,非敏感用地污染物的总致癌风险以及危害商较低。  相似文献   

7.
2007~2008年进行的北京市平原区地下水污染调查,发现该地区地下水有机污染具有检出种类多、检出率高、浓度低的特点。主要的有机污染物为三氯甲烷、四氯化碳、1,2-二氯丙烷、1,2-二氯乙烷、三氯乙烯、四氯乙烯、甲苯和苯并[a]芘。对这8种主要有机污染物的时间和空间分布特征进行了研究。研究显示,平面上,有机污染物分布广泛,主要为点状分布,局部地区集中检出。垂向上,随深度增加地下水有机污染减轻(1,2-二氯乙烷除外)。与枯水期相比,丰水期有机物检出率和浓度更高(三氯甲烷除外),四氯化碳、三氯乙烯、四氯乙烯受枯、丰水期变化影响最小,检出重现性好,污染较严重。与2001年相比,2008年四氯化碳检出率降低,对地下水的污染有所减轻,而三氯甲烷、三氯乙烯、四氯乙烯的检出率变化较小。文章从污染源、有机物理化特性、水文地质条件等方面对有机污染时空分布特征的成因进行了阐述。  相似文献   

8.
北京市平原区地下水有机污染时空分布特征   总被引:2,自引:2,他引:0       下载免费PDF全文
2007~2008年进行的北京市平原区地下水污染调查,发现该地区地下水有机污染具有检出种类多、检出率高、浓度低的特点。主要的有机污染物为三氯甲烷、四氯化碳、1,2-二氯丙烷、1,2-二氯乙烷、三氯乙烯、四氯乙烯、甲苯和苯并[a]芘。对这8种主要有机污染物的时间和空间分布特征进行了研究。研究显示,平面上,有机污染物分布广泛,主要为点状分布,局部地区集中检出。垂向上,随深度增加地下水有机污染减轻(1,2-二氯乙烷除外)。与枯水期相比,丰水期有机物检出率和浓度更高(三氯甲烷除外),四氯化碳、三氯乙烯、四氯乙烯受枯、丰水期变化影响最小,检出重现性好,污染较严重。与2001年相比,2008年四氯化碳检出率降低,对地下水的污染有所减轻,而三氯甲烷、三氯乙烯、四氯乙烯的检出率变化较小。文章从污染源、有机物理化特性、水文地质条件等方面对有机污染时空分布特征的成因进行了阐述。  相似文献   

9.
某储油库地下水有机污染健康风险评价   总被引:10,自引:2,他引:8  
本文以USEPA推荐使用的污染场地健康风险评价方法为基础, 结合污染场地实际情况, 分析、评价了某储油库地下水有机污染对场址内暴露人群造成的健康风险。评价结果表明: 该储油库地下水有机污染物为1,2-二氯乙烷、苯、三氯甲烷和甲苯。污染场址内的工人和居民受到的非致癌风险均小于1, 在可接受范围; 而污染对场址内的工人和居民产生的致癌风险较大, 分别为1.7×10?4、9.0×10?3, 是不可接受的。产生致癌风险的主要污染物为1, 2-二氯乙烷, 占总致癌风险的99.80%, 可致人产生多种形态的肿瘤, 并具有潜在的遗传毒性。主要暴露途径是吸入吸收, 占总致癌风险比例大于70%, 其次为口入吸收。皮肤接触暴露途径产生的致癌风险较小, 占总致癌风险比例小于1%。  相似文献   

10.
`土壤-地下水耦合数值模拟是定量刻画水流和溶质运移的主要手段。现有大范围场地尺度的研究受到数据采集难度及模拟计算量的限制,多是将土壤和地下水分成两个系统,这种方式不利于模型之间的计算反馈,易出现计算误差,因此将土壤和地下水作为整体系统研究具有重要意义。为精确刻画实际场地土壤-地下水系统中污染物迁移规律,揭示变饱和反应溶质迁移模型的参数敏感性,以某铬污染场地为研究对象,基于现场试验及前人研究所获数据,采用Galerkin有限元法建立三维土壤-地下水模型,定量描述六价铬在土壤-地下水中的迁移规律。在此基础上,通过改变补给条件,研究潜水面在土壤-地下水系统中的波动。并讨论阻滞系数和反应常数对溶质运移的影响。结果表明:在土壤中,污染物最大水平迁移距离为场地东南侧300 m;地下水中污染晕最大分布面积约为1.632 km2;垂向上土壤中的六价铬仅需15.6 h即可下渗至潜水面,第6天贯穿含水层。当潜水面随着补给量变化而波动时,地下水中六价铬会随水流进入土壤,影响土壤中污染分布。对溶质运移参数的讨论显示,当反应常数由0增大至10?6 s-1时,迁移出场区边界时地下水中污染物浓度约减少2000 mg/L,较难迁移至涟水河。基于FEFLOW的数值模型,能够解决各系统之间交互性差的问题,提供较为精确的模拟结果。  相似文献   

11.
加拿大联邦及Alberta省级环境导则为石油烃污染场地提供了多级环境标准及评价方法。其中二级环境标准评价,准许根据污染场地的实际条件计算土壤和地下水污染限值。环境导则限定了计算污染限值的模型和方法。这些模型大都是基于十分简化的野外条件的解析解模型,并根据导则规定的方法使用,以简化应用与审批程序。这些模型的用途和方法与一般通用地下水和土壤污染物运移模型有所不同,在实际运用时这些差别常常被忽略。同时,在复杂野外条件下运用这些模型时,经常遇到确定模型输入参数的困难。介绍了加拿大环境导则中计算污染场地土壤和地下水污染限值以保护地表水环境的模型方法,强调这些模型方法只适用于计算污染限值的特殊目的,不适用于预测污染物运移或套用一般模型拟和调参方法。结合具体计算实例,探索运用Monte Carlo方法评价与表示模型输入参数带来的不确定性。这种方法用参数变化区间(或概率分布)来表示输入参数的变化或不确定性,以求得具有统计意义的保险污染限值。这种方法简单易行,却将二级环境标准评价方法推广到较为复杂(更真实)的野外条件。  相似文献   

12.
成都平原农田区土壤重金属元素环境基准值初步研究   总被引:5,自引:0,他引:5  
土壤重金属污染已成为制约人类社会发展及危害人类健康的重要因素,制定土壤重金属元素的环境基准值对控制土壤重金属污染及保护生态安全具有重要意义。以成都平原农田区为例,以保护地下水安全为目的,以室内模拟淋溶实验为手段,尝试性地计算了研究区不同类型土壤重金属元素的环境基准值。研究结果表明:(1)不同类型土壤各元素在土壤—水间的分配系数差异较大;(2)不同类型土壤Hg和Cd环境基准值差异不大,Hg环境基准值平均为0.3μg/g,Cd的变化范围为0.3~0.5μg/g;As和Pb环境基准值差异较大,As的变化范围为18~24μg/g;Pb的变化范围为24~41μg/g;(3)研究区土壤基本处于保护饮用水的安全范围之内,但黄壤中Pb、紫色土中Cd和Pb、棕壤中Hg和Pb具有潜在的影响地下水安全的生态风险。这对研究区进行风险评估具有重要的参考价值。  相似文献   

13.
The Zlata Idka village is a typical mountainous settlement. As a consequence of more than 500 years of mining activity, its environment has been extensively affected by pollution from potentially toxic elements. This paper presents the results of an environmental-geochemical and health research in the Zlata Idka village, Slovakia. Geochemical analysis indicates that arsenic (As) and antimony (Sb) are enriched in soils, groundwater, surface water and stream sediments. The average As and Sb contents are 892 mg/kg and 818 mg/kg in soils, 195 mg/kg and 249 mg/kg in stream sediments, 0.028 mg/l and 0.021 mg/l in groundwater and 0.024 mg/l and 0.034 mg/l in surface water. Arsenic and Sb concentrations exceed upper permissible limits in locally grown vegetables. Within the epidemiological research the As and Sb contents in human tissues and fluids have been observed (blood, urine, nails and hair) in approximately one third of the village’s population (120 respondents). The average As and Sb concentrations were 16.3 μg/l and 3.8 μg/l in blood, 15.8 μg/l and 18.8 μg/l in urine, 3,179 μg/kg and 1,140 μg/kg in nails and 379 μg/kg and 357 μg/kg in hair. These concentrations are comparatively much higher than the average population. Health risk calculations for the ingestion of soil, water, and vegetables indicates a very high carcinogenic risk (>1/1,000) for as content in soil and water. The hazard quotient [HQ=average daily dose (ADD)/reference dose (RfD)] calculation method indicates a HQ>1 for groundwater As and Sb concentrations.  相似文献   

14.
Historic spillages of chlorinated hydrocarbons at a vinyl chloride plant in the Rotterdam–Botlek area in The Netherlands has lead to deep-seated pollution of the underlying aquifer. The principal pollutant is 1,2-dichloroethane (1,2-DCA). As a temporary measure, the contamination is being contained using a pump and treat system. In the long term, in-situ bioremediation has been proposed using a biologically active zone where pollutants would be dechlorinated by microorganisms that simultaneously degrade other carbon sources. In order to investigate the suitability of this new technology, a programme of laboratory tests was carried out. The laboratory programme involved a series of anaerobic soil column tests, where the selection and delivery of different carbon substrates that stimulated 1,2-DCA dechlorination were investigated. The soil columns were prepared using soil and groundwater samples from boreholes. Groundwater was flushed through the columns under anaerobic conditions. A comparison was made between the transformation of 1,2-DCA without a carbon substrate and in the presence of sugars (molasses) and alcohol (methanol) respectively. In addition, different modes of delivery were investigated. In the case of molasses, the material was injected into the column as a plug to simulate grout injection in the field, whereas methanol was delivered as a constant flow dissolved in the influent. Both carbon substrates resulted in the biotransformation of 1,2-DCA. However, fermentation of molasses produced secondary effects that led to a drop in pH and an excessive production of carbon dioxide, which temporarily blocked the flow of groundwater.  相似文献   

15.
The impact of waste disposal on trace metal contamination was investigated in eleven wetlands in the Lake Victoria Basin. Samples of soil, water and plants were analysed for total Zn, Cu, Pb and Ni concentrations using flame atomic absorption spectrophotometry. The trace metal concentrations in soil were the highest in Katanga wetland with the highest mean concentrations of 387.5±86.5 mg/kg Zn, 171.5±36.2 mg/kg Pb, 51.20±6.69 mg/kg Cu and 21.33±2.23 mg/kg Ni compared to the lowest levels observed at Butabika (30.7±3.2 mg/kg Zn, 15.3±1.7 mg/kg Pb, 12.77±1.35 mg/kg Cu and 6.97±1.49 mg/kg Ni). Katanga receives waste from multiple industrial sources including a major referral city hospital while Butabika is a former solid waste dumpsite. Wetland soil near a copper smelter had a Cu concentration of 5936.3±56.2 mg/kg. Trace metal concentrations in industrial effluents were above international limits for irrigation water with the highest concentrations of 357,000 μg/L Cu and 1480 μg/L Zn at a Cu smelter and 5600 μg/L Pb at a battery assembling facility compared to the lowest of 50 μg/L Cu and 50 μg/L Zn in water discharged from Wakaliga dumpsite. Uptake of trace metals from soil differed from plant to plant and site to site. Higher levels of trace metals accumulated in the root rather than in the rhizome and the least amount was in the leaf. The study identifies industry as a potential source of trace metal contamination of water and the environment pent-up need for policy intervention in industrial waste management.  相似文献   

16.
Wetland is a transition zone between terrestrial and aquatic ecosystems, and is the source and sink of various biogenic elements in the earth’s epipelagic zone. In order to investigate the driving force and coupling mechanism of carbon (C), nitrogen (N) and phosphorus (P) migration in the critical zone of lake wetland, this paper studies the natural wetland of Dongting Lake area, through measuring and analysing the C, N and P contents in the wetland soil and groundwater. Methods of Pearson correlation, non-linear regression and machine learning were employed to analyse the influencing factors, and to explore the coupling patterns of the C, N and P in both soils and groundwater, with data derived from soil and water samples collected from the wetland critical zone. The results show that the mean values of organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) in groundwater are 1.59 mg/L, 4.19 mg/L and 0.5 mg/L, respectively, while the mean values of C, N and P in the soils are 18.05 g/kg, 0.86 g/kg and 0.52 g/kg. The results also show that the TOC, TN and TP in the groundwater are driven by a variety of environmental factors. However, the concentrations of C, N and P in the soils are mainly related to vegetation abundance and species which influence each other. In addition, the fitted curves of wetland soil C-N and C-P appear to follow the power function and S-shaped curve, respectively. In order to establish a multivariate regression model, the soil N and P contents were used as the input parameters and the soil C content used as the output one. By comparing the prediction effects of machine learning and nonlinear regression modelling, the results show that coupled relationship equation for the C, N and P contents is highly reliable. Future modelling of the coupled soil and groundwater elemental cycles needs to consider the complexity of hydrogeological conditions and to explore the quantitative relationships among the influencing factors and chemical constituents.  相似文献   

17.
In order to study the distribution and evolution features of saline soil, the correlations between the groundwater depth, salinity and salinization of soil are examined through analyzing the hydrometeorological data and distribution maps of saline soil, groundwater depth and salinity in 1957 and 2005. The results show that the area of salinization has generally decreased. The area of salinization decreases with the increasing groundwater depth, and the dynamic evolution characteristics appeared between the groundwater depth and area of salinization. The area of heavy salinization is greatest when the groundwater salinity is > 5 g/L, the area of moderate salinization is greatest when the groundwater salinity is between 2-5 g/L, the area of light salinization is greatest when the groundwater salinity is 1-2 g/L and the area of non-salinization is greatest when the groundwater salinity is <1 g/L. The area of heavy salinization was characterized with groundwater depth <2.5 m and salinity >1.8 g/L. The area of non-salinization was characterized with groundwater depth >4.0 m and salinity 0.2-1.5 g/L.  相似文献   

18.
为了阐明平原区排污河渠对地下水水质的影响程度和影响范围,以鲁北平原一条未采取防渗措施的多年排污河渠为例,进行了河渠污水对两侧浅层地下水污染机理的研究。通过Mg^2+、Cl^-、1,2-二氯乙烷等主要污染指标在排污河渠两侧的扩散规律研究,初步确定排污河渠对两侧浅层地下水综合质量的影响范围约为100 m。此结论为平原区浅层地下水的防污、治污提供了一定的参考依据。  相似文献   

19.
Concentrations of organochlorine pesticides (Lindane, Aldrin, Dieldrin, Endosulfan, DDT and DDE) residues in beef samples from the Kumasi and Buoho abattoirs in Ghana were determined using gas chromatography. Organochlorine residues were found in all the samples. The average concentration of lindane in beef fat samples from Kumasi was 4.03 μg/kg and 1.79 μg/kg in beef fat from Buoho. The average levels of lindane were 2.07 μg/kg for lean meat samples from Kumasi abattoir and 0.60 μg/kg in lean meat samples from Buoho. Endosulfan concentration in meat samples from Buoho was 2.28 μg/kg in the fat and 0.59 μg/kg in the lean beef. 1,1-dichloro-2,2-bis(p-dichlorodiphenyl)ethylene (DDE) recorded mean concentrations of 118.45 μg/kg in beef fat and 42.93 μg/kg in lean beef samples from Kumasi abattoir. Beef samples from Buoho had DDE concentration of 31.89 μg/kg in the fat and 5.86 μg/ kg in the lean beef. 1, 1, 1-trichloro-2, 2-bis-(4′-chlorophenyl) ethane (DDT) recorded an average concentration of 545.22 μg/kg in beef fat and 18.85 μg/kg in lean beef samples from Kumasi abattoir. The average concentration of DDT in beef fat from Buoho was 403.82 μg/kg but lean meat samples from the same sampling site recorded mean concentration of 10.82 μg/kg for DDT. Although, most of the organochlorine residues detected were below the maximum limits set by the FAO/WHO, bioaccumulation of these residues is likely to pose health problems in higher organisms like human beings.  相似文献   

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