【作者】 刘静；

【导师】 崔兆杰；

【作者基本信息】 山东大学 ， 环境工程， 2007， 博士

【摘要】 本论文在全面综述土壤环境中有机污染物的分离分析方法、来源解析技术、吸附/解析机理、土壤特性参数对污染物分布影响的基础上,系统研究优化了样品前处理技术、建立了快速准确的土壤中超痕量的类二噁英类和阻转类多氯联苯（PCBs）同系物的分离分析方法;制订了区域土壤采样方案,研究得到了现代黄河三角洲地区土壤中类二噁英类和阻转类PCBs的污染现状和污染特征;进而利用主成分分析方法（PCA）对现代黄河三角洲土壤中的PCBs污染来源进行了解析,从而建立了土壤环境中PCBs污染源的识别和解析方法,得到了各种污染源的贡献率;提出并定义了毒害性、持久性、生物累积性三种分污染指数和综合污染指数的概念,建立了相关的数学表达式,综合考虑PCBs的毒性、环境持久性和生物累积性等因素,构建了评价土壤中PCBs污染现状的评价方法;研究了土壤坏境中PCBs的三维空间分布规律,找到了影响PCBs分布的主要土壤环境特性因素。本研究为进一步揭示土壤环境中有机污染物的成因、迁移转化机理和归趋研究奠定了理论基础。论文研究内容及结论如下:①土壤环境中PCBs的前处理技术研究利用索氏提取技术,优化确立了PCBs的索氏提取最优条件,实现了土壤样品中有机污染物的高效提取。得到的最佳索氏提取条件为:索氏提取时间24h、回流速度3～4次/h、混合提取溶剂正己烷/丙酮（1:1V/V）的用量为200mL/50g;采用12种类二噁英类PCBs评价了方法的提取效率,在最佳提取条件下,12种PCBs的50g土基质加标回收率为82.6%～109.8%,相对标准偏差为1.1～6.3%。与本实验室进行的超临界流体萃取效果相比,具有提取效果好、样品处理量大、处理成本较低等优点。研究了US.EPA Method3665采用的PCBs的酸洗结合氟罗里土柱净化方法,确定了操作条件,对内装1000mg、6mL的氟罗里土的商品净化柱,洗脱溶剂正己烷的用量为20mL。同时用12种类二噁英类PCBs评价了浓硫酸/高锰酸钾和商品氟罗里土柱净化方法的回收率。浓硫酸/高锰酸钾酸洗氧化过程中12种类二噁英类PCBs标样的回收率为88.0%～112.8%,PCBs在浓硫酸酸洗过程中损失少,分解作用小;12种类二噁英类PCBs标样在氟罗里土柱上用20mL正己烷洗脱,回收率为88.1%～106.6%,商品氟罗里土柱净化效果好,回收率高。净化步骤的总回收率在83.0%-109.0%之间,净化损失小。②土壤样品中类二噁英类PCBs的双毛细管柱高效气相色谱分析方法研究选用弱极性和中极性双毛细管柱色谱互补分离技术对样品中的类二噁英类PCBs进行定性定量分析,解决了12种类二噁英类PCBs和非类二噁英类PCBs同系物和残存有机氯农药共洗脱的问题,建立了简便准确的12种类二噁英类PCBs的定性定量分析方法。利用气质联用（HRGC/MS）选择特征离子SIM技术验证双柱HRGC方法定性的准确性,证明在选定的色谱分离条件下,双柱互补分离可排除对12种类二噁英类PCBs分析的干扰。利用平行样品、分析基质加标回收和空白加标回收的方法测定了分析仪器和分析方法的精密度、准确度和方法检测限,并对采自黄河三角洲的土壤、沉积物和降尘三种实际样品进行了测定。结果表明,12种类二噁英类PCBs的加标回收率在82-109.8%之间;六次平行样品测量的相对标准偏差在1.62-14.84%;方法检测限在1.5-3.9ng.kg^-1。本研究建立的方法精密度高、准确性好,检测限低,在环境监测和研究领域具有广阔的应用前景。③土壤中阻转类PCBs的保留指数分析方法研究选用12种类二噁英类PCBs混合标样为参照样品,选用文献报道的PCBs保留指数和相对响应因子数据,计算得到了19种阻转类PCBs的定性定量参数,经5种不同氯取代的阻转类PCBs标样验证该方法科学可行。采用建立的方法测定了采自黄河三角洲地区的士壤、沉积物和降尘三种实际样品。建立了使用线性凹归系数这一定量指标评价PCBs文献数据对本研究采用的实验系统适用性的评价方法。建立了校正保留指数和相对响应因子等文献数据的方法,文献数据经校正方程校正,可消除文献和本研究所采用的两套分析系统的间的系统误差。该方法拓展了文献数据的应用范围。④现代黄河三角洲地区土壤中类二噁英类和阻转类PCBs的污染现状和特征现代黄河三角洲土壤中类二噁英类PCBs的含量在108.7-2153ng·kg^-1之间,平均800.5ng·kg^-1,其毒性当量值范围在2.3×10⁵-9.5×10^-3ng-TEQ/kg之间,毒性贡献值较低;阻转类PCBs的含量在46.8ng·kg^-1-619.3ng·kg^-1之间。类二噁英类PCBs中PCB118含量最高,占总类二噁英类PCBs含量的46.7%;以五氯联苯为主,占总类二噁英类PCBs的60%以上。运用类二噁英类和阻转类PCBs的实测数据结合文献报道的商品PCBs中两类PCBs所占比例计算得到的PCBs,总量最高值与国内各大江大河地区沉积物中的PCBs含量处于同一数量级,多数计算值高于清洁地区土壤中的含量,低于国外土壤容许含量标准值,现代黄河三角洲地区土壤中的PCBs污染属轻度污染。⑤土壤中PCBs的来源解析研究利用环境统计分析技术-主成分分析方法,建立了现代黄河三角洲地区土壤中PCBs的来源解析方法。对现代黄河三角洲地区表层土壤样品中类二噁英类PCBs浓度的定量分析数据进行解析,得到该地区的来源解析结果:现代黄河三角洲地区土壤存在四种类型的PCBs污染源:第一类源是最重要的PCBs污染源,其污染途径是黄河沿岸企业排污中含有的PCBs与地面径流中泥沙结合传输至三角洲地区形成的污染,对现代黄河三角洲地区土壤污染的贡献率为49.6%;第二类和第三类污染来源影响面较小,仅位于沿海2个采样点处,可能是油田采油作业导致的绝缘油或导热油泄露等点源污染所致,但影响程度较高,对研究区污染的贡献率分别为15.0%和10.1%;第四类影响范围广的污染源是大气的干、湿沉降,其对研究区污染的贡献率是8.4%。对四种污染源的组成进行了分析,结论是现代黄河三角洲地区土壤中的PCBs污染主要是国产PCBs的生产和使用造成的,产品主要成分与Aroclor1242相对应。两个点源污染的成分不同,其中之一是与Aroclor1221和1242相对应的两种商品PCBs污染叠加而成;另一种点源污染的主要成分与Arclor1260相对应。大气干、湿沉降的污染组成复杂,是由Aroclor1242、1248、1260中各种高氯含量的成分共同叠加的结果。⑥土壤环境中PCBs污染评价方法研究本研究借鉴综合污染指数的概念,引入加拿大环境理事会制订的土壤中PCBs标准指标,提出了PCBs污染的毒害性转换系数（Ti）、持久性转换系数（Pi）和生物累积性转换系数（Bi）转换方法,提出土壤环境中PCBs的毒害性、持久性和生物累积性三种分污染指数及PCBs的综合污染指数概念,建立了相关表达式;创新性地构建了综合考虑PCBs同系物毒害性、持久性及生物累积性的PCBs污染合理和全面评价方法。利用建立的土壤中PCBs的污染评价方法评价了现代黄河三角洲地区土壤中的PCBs污染现状,定量评价了每个采样点和整个现代黄河三角洲地区的PCBs污染,得到了该地区土壤中PCBs污染属轻度污染的结论,与定性评价结果吻合。该评价体系科学合理地考虑了PCBs同系物间的特性差异,在持久有机污染物（POPs）的污染评价方面具有很高的理论和推广价值。⑦现代黄河三角洲地区土壤中类二噁英类PCBs的空间分布规律研究现代黄河三角洲地区土壤中类二噁英类PCBs的分布规律总体为:沿黄河水流的纵向方向上的分布呈明显的地域性,位于三角洲上游的一号单元土壤中PCBs浓度最低,高浓度区出现在现代黄河三角洲中部的二号单元区内,三角洲下游地区的三号单元中PCBs浓度较高;横向上从河床到陆地PCBs的浓度呈下降趋势;垂直方向上,随深度的增加,PCBs的浓度降低,但下降幅度不大;综合三个方向得到PCBs的空间分布规律。空间分布规律表明:PCBs污染较重的地区集中在现代黄河三角洲中部的2号地区;地表径流是该地区土壤中PCBs的主要来源;大气沉降可能是该地区PCBs污染的主要来源之一。⑧现代黄河三角洲地区土壤环境因素对PCBs污染分布的影响研究使用数学统计学分析方法—相关性研究方法研究了现代黄河三角洲地区土壤的环境因素对PCBs分布的影响:土壤有机质含量与类二噁英类PCBs的总含量呈弱的正相关关系。土壤粒径组成中粘粒含量与类二噁英类PCBs的总含量呈相关性关系,且达到极显著的水平;土壤粒径组成中粉砂粒的含量与类二噁英类PCBs的总含量无相关关系;土壤粒径组成中砂粒含量与类二噁英类PCBs的总含量呈负相关性关系,达到显著相关的水平。土壤总盐含量与类二噁英类PCBs的含量没有明显的相关性。可见,土壤颗粒组成中粘粒含量和砂粒含量、土壤中有机质含量是影响PCBs分布的主要因素。更多还原

【Abstract】 In this study, on the basis of the review of former researches about the analysis methods, source apportionment approaches and distribution trends in soils, the pretreated method, separation instrument method were studied systematically; The rapid and accurate analysis methods for trace dioxin-like and atropisomeric PCBs in soil samples were set up; The PCBs sampling scheme of soil in the Yellow river delta was worked out and the current status and pollutant characteristic of 12 dioxin-like and 19 atropisomeric PCBs congeners in the soil of modern the Yellow River delta （China） are investigated using the established analysis method; Then the source apportionment of PCBs in soil for the Yellow River delta was carried out by PCA （principal component analysis） model, the types of pollution sources and their contribution percentage were calculated; With the integration of PCBs toxicity, persistence and bio-accumulation, the PCBs pollution was defined as toxicity, persistence and bio-accumulation sub-pollution indexes and total pollution index （PI）, the calculation equations were expressed and the evaluation method was built, the evaluation of the PCBs pollution in the modern Yellow River delta was accomplished successfully; The spatial distribution rules of PCBs were determined and the influences of the soil characteristics to the PCBs distribution were studied and the main influencing factors of soil characteristic parameters on PCBs distribution were determined by correction analysis. This study provided a theory basis for the researching of forming transportation, transformation and fating of organic pollution in soil. This dissertation included the following contents and conclusions:①Pretreated technique studies for the extraction of organic pollutants in soil samplesSolhex extraction conditions were optimized in order to achieve effective extraction of organic pollutants. The optimized soxhlex extraction conditions were listed as followed: extraction time was 24h. recycle rate was 3～4 times per hour and the amount of mixture solvent （n-hexane/acetone 1:1V/V） was 200mL/50kg. The extraction effective was determined by 12 dioxin-like PCBs. The average recovery rates of 12 dioxin-like PCBs were in range of 82.6%～109.8%. and the recovery rates RSD of 12 dioxin-like PCBs were in range of 1.1-6.3%. Compared to the supercritical fluid extraction （SFE） studied in our lab which the recoveries of 12 dioxin-like PCBs ranged from 73.0%～129.0% and the method precision is in the rang of 1.0%～10.5%. The conclusion that the Solhex extraction method has obvious advantages on better extraction efficiency, more sample treatment amount and lower pretreated payment were reached.The purification methods employed by US.EPA Method 3665 were studied and the operation conditions were determined. The optimized amount was 20mL for a Florisil column filled with 1000mg、6mL Florisil. In the meantime the recoveries of 12 dioxin-like PCBs of 98% sulfuric acid/potassium permanganate and Florisil column purification methods were in range of 88.0%～112.8% and 94.8%～106.6% individually. These experiments testified that the 98% sulfuric acid/potassium permanganate and Florisil column purification methods are effective and lower lose of target PCBs.②Dual high resolution capillary column HRGC/ECD method for the determination of dioxin-like PCBs in soilA rapid and accurate method has been developed for determination of 12 dioxin-like polychlorinated biphenyls （dl-PCBs） in samples using complementary separation on dual columns system with low and intermediate polarities. Qualitative and quantitative analysis of dl-PCBs were performed by the two retention data on dual capillary gas chromatography with a 63Ni electron capture detection （GC/ECD）, the co-elution between 12 dl-PCBs and the bulk PCBs and pesticides was solved. The accuracy of qualitative analysis was confirmed by the gas chromatography mass Spectrometry （GC/MS） using selective ion mode （SIM） technique. The method has been validated: precision was estimated from the relative standard deviation （RSD） of the six duplicate analyses of a soil sample, and the RSDs of 12 dioxin-like PCBs was in ranged of 1.6-14.9%; accuracy was estimated from the recovery of spiked analyses from the soil matrix; The recoveries of target analysts were found to be in the range of 82.0-112.0%; The method detection limits （MDLs） of 12 dioxin-like PCBs were in range of 1.5-3.9ng·kg^-1 . The applications of this analysis method to the determination of dioxin-like and atropisomeric PCBs in dust-deposition, sediment and soil samples from the Yellow River delta has been carried out successfully. The conclusion that this analysis method has higher precision, accuracy and lower MDLs can be reached. This method can be used widely in environmental monitoring and research.③Retention index analysis method studies for the determination of atropisomeric PCBsA new method that determinate the qualification and quantification parameters of 19 PCBs by using PCBs retention indices （RIs） and relative response factors （RFs） databases in literature, a PCBs standard reference （12-dioxin-like PCBs） and 5 of 19 target PCBs congeners with different numbers of chlorine atoms rather than target PCBs standards was proposed. The applicability evaluation and revision method of the PCBs databases were set up; and the database whose RIs or RFs exhibit the best linear relationships with the experimental Rts and RFs of 12 dioxin-like PCBs reference series on temperature programmed capillary columns Rtx-5 column were employed to calculate the Rts and RFs of 19 atropisomeric PCBs congeners under the same analysis condition. 5 of 19 target PCBs congeners with different numbers of chlorine atoms were selected to confirm the quality of the calculated values. The calculated qualification-Rts and quantification-RFs results showed good agreement with the experimental values. The devise equation can decrease the system deviation between analysis system used in literature and in our lab. The proposed method can revise the database in literature increase their application range. The applications of this method to the determination of dioxin-like and atropisomeric PCBs in dust-deposition, sediment and soil samples from the Yellow River delta has been carried out successfully.④Current status and pollution characteristic of 12 dioxin-like and 19 atropisomeric PCBs in the soil of the Yellow River delta （China） are investigated in this paper. The concentrations of the dioxin-like PCBs are found in the range of 108.7 to 2153 ng·kg^-1 dry weigh with an average of 800.5 ng·kg^-1 dry weigh. Thetoxic equivalency （TEQ） in this area varies from 2.3×10^-5 to 9.5×10^-3 ng-TEQ kg^-1 dry weight. While the concentrations of the atropisomeric PCBs are found in the range of 46.8 to 619.3ng·kg^-1 dry weigh. PCB118, the main congener, accounts for 46.7% of the 12 dioxin-like PCBs in the soil samples. More than 60% polychlorinated biphenyls are contributed by Penta-PCBs. According to the TEQ and PCBs standard in soils, combined the total PCBs value calculated by the percentages of the 12 dioxin-like and 19 atropisomeric PCBs in commercial PCBs. the pollution status and toxic contribution of PCBs in the modern Yellow River delta were insignificant. ⑤Source apportionment for PCBs in soils.The environmental statistic analysis method-Principle component analysis （PCA） was employed to achieve source apportionment for PCBs in soil from the Yellow River delta. The result indicated that that there were four types to the contaminate sources affecting the PCBs distribution pattern. The first kind of sources was the most significant and largest influence range. The first type PCBs source was from the sand and mud associated with pollutants which was discharged to the Yellow river by the enterprises along the river, and this water runoff contributes 49.6% of the total contaminant burden in the Delta; The second and third types of PCBs source were just belong to the I and 5 sample sites individually, and we can determined that the sources were point sources which may be from the leakage of capacitors during the oil exploitation, the point sources contribute 15.0% and 10.1% of the total contaminant burden in the Delta individually; The fourth kind of source has widely but less influences is believed to be from the atmospheric dry and wet precipitation, it contributes 8.4% of the total contaminant burden in the Delta. The composition of the principle components were discussed too. The results showed that the composition of the first source was native commercial PCBs application, its composition was correspondence with Arclor 1242; the second composition was similar to Arclor 1221 and Arclor 1242, and the third composition was similar to Arclor 1260. the forth composition was very complicated and it consists of Aroclor1242、1248 and 1260. The results will support the controlling and management of the PCBs pollution.⑥Study of the evaluation method of PCBs pollution in soilAn evaluation method for PCBs pollution in soil was set up for the first time by referring to the conception of pollutant index. The standard value series of total PCBs employed by National guideline and standards office, Canada and the toxicity, persistence, and bio-accumulation transformation indexes were introduced into the evaluation model. With the integration of PCBs toxicity, persistence, and bio-accumulation, three sub-pollution Indexes for PCBs toxicity, persistence, and bio-accumulation and pollution index were defined and the relevant expressions were set up too. Then by the application of the evaluation method the PCBs Pollution Index in the Yellow River delta soil were calculated and the PCBs evaluations in 22 soil sample stations were accomplished successfully, and the quantification results were fit for the qualification method. The result obtained from this method makes people understand the PCBs pollution current status easily, clearly and completely. This evaluation model considered the characteristic differences between congeners scientifically and comprehensively, and should be employed in evaluations of persistent organic pollutants （POPs）.⑦The spatial distribution trends of PCBs pollution:The distribution trends of dioxin-like PCBs in soil from modern Yellow River delta were summarized as followed: PCBs trend in the direction of water flow are strongly depends on the sample locations where the sediment characteristics were affected by the time the soil was formed, the locations in upstream of the Delta were slightly polluted, while the highest PCBs concentrations located in the middle part of the Delta, and the higher concentrations of PCBs were at the downstream Delta; in the direction across the river, the closer are the sample stations to the river bed, the higher levels of the dioxin-like PCBs are detected; with the increase of soil depth, the concentrations of the contaminants decreased gradually. The distribution rules of dioxin-like PCBs suggested that the water runoff is the main source of the total contaminant burden in the Delta, and atmospheric precipitation plays an important role.⑧The influence factors of the physic-chemical parameters on the PCBs distribution were determined by correction statistic analysis method: The relationship between the total PCBs concentrations in 22 samples and the composition of soil particles were that the total PCBs concentrations had a greatly significant positive correlation with clay content, while they had a significant negative correlation with sand content and had no correlation with silt content. The relationship between the total PCBs concentrations in 22 samples and the TOC content using similar methods was that the total PCBs concentrations had a significant positive correlation with the TOC content. However the total PCBs concentrations had no correlation relation with dissolved salt content. This result indicated the clay and sand contents of soil practical composition, the TOC content were the main influencing factors on the PCBs distribution.更多还原