环糊精提取技术评估土壤PAHs生物有效性的机制与模型

发布时间：2018-01-13 19:20

  本文关键词：环糊精提取技术评估土壤PAHs生物有效性的机制与模型　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 环糊精提取技术 多环芳烃 生物有效性 评估模型 生态风险

【摘要】：多环芳烃(Polycyclic Aromatic Hydrocarbon,PAHs)是一类典型的疏水性有机污染物,广泛存在于土壤中,且具有致畸、致癌和致突变效应。羟丙基-β-环糊精(Hydroxypropyl-β-cyclodextrin,HPCD)提取技术是评估污染物生物有效性的技术之一,主要用于开展HPCD对污染物的生态风险评估。然而由于目前所研究污染物的种类单一,使其忽略了污染物之间的化学多样性的影响,进而使得HPCD提取技术评估污染物生物有效性的机制认识不够完善。本研究采用野外土壤综合考察HPCD对15种PAHs的包合作用、脱附性能及蚯蚓富集的影响,分别从PAHs环境赋存、生物效应等方面明确PAHs的化学多样性及HPCD对土壤中PAHs的提取机制,从而阐明HPCD提取评估土壤中PAHs生物有效性的机制并在此基础上建立HPCD提取与蚯蚓富集的预测模型。通过加速溶剂提取技术测试了31种土壤中15种PAHs的总量。通过双比值法分析表明高速公路附近土壤的PAHs主要来自化石燃料高温燃烧,化工厂、焦化厂和农田附近PAHs主要来自石油挥发和煤、木材等燃烧,而港口附近的PAHs主要为复合污染。通过对土壤中PAHs总量与土壤理化性质的相关性分析可知,土壤中PAHs的总量与土壤有机碳含量、比表面积、土壤粘粒分数和砂粒分数正相关,其关系式为CPAHs=0.48X1+0.33X2+0.36X5+0.20X7(R2=0.95,n=31)不同种类PAHs的浓度分别与土壤有机碳含量、比表面积、孔容、孔径、粒级分数和风化指数相关(R2=0.54～0.94,n=31)。结果表明,不同种类PAHs的环境赋存存在差异。通过蚯蚓富集实验研究了蚯蚓对不同土壤中PAHs的富集能力。结果表明,PAHs未校正及校正BSAF的平均值分别在0.06±0.04(1nP)～0.18±0.10(Nap)和0.12±0.05(1nP) ～0.35±0.11(Nap)之间。根据Statistic Package for SOcial Science(SPSS)相关性分析表明,不同种类PAHs的未校正BSAF与土壤和PAHs的理化性质相关,其关系式为logBSAF=-0.98X3+0.35X5+0.48X8+0.15X9-1.00X11+0.45X15-0.28X16(R2=0.80,n=390),其相关性因素分别为有机碳含量、分子极化率、粘粒分数、粉粒分数、摩尔体积和生物降解速率,其中土壤有机碳含量和PAHs的分子极化率对BSAF (Biota-Soil Accumulation Factor.的贡献较大。结果表明,蚯蚓对PAHs富集能力的差异是PAHs的自身理化性质及环境赋存共同作用的结果。通过HPCD脱附动力学实验及有效态提取技术研究了HPCD提取评估土壤中PAHs生物有效性的机制,并在此基础上建立HPCD提取与蚯蚓富集之间的预测模型。通过SPSS相关性分析表明,PAHs的HPCD提取浓度与土壤总量浓度的比值及BSAF二者共同与土壤有机碳含量、生物降解速率、粘粒分数和粉粒分数相关,其中有机碳含量贡献最大。HPCD提取后土壤理化性质的变化与蚯蚓富集过程类似,二者均使土壤中的大颗粒转化为小颗粒且比表面积增大,且反应HPCD包合能力的包合常数与反应蚯蚓富集能力的BSAF共同与PAHs分子极化率和摩尔体积相关。结果表明,HPCD提取过程能够模拟蚯蚓在土壤中的富集过程且二者可能具有相关性。利用SPSS曲线估计建立26种土壤中15种PAHs蚯蚓体内浓度与HPCD提取浓度的逐一预测模型(Cworm=((CHPCD+k)/a)0.5+h)(R2=0.88～0.95,n=26))。将18种土壤中15种PAHs的单个及总量浓度混合,建立蚯蚓体内浓度与HPCD提取浓度之间的混合模型,Cworm=((CHPCD+91.58)/0.0049)0.5-136.96(R2=0.96,n=270),并随机选取4种不同类型的8种土壤对预测模型进行验证。结果表明,通过模型得到的蚯蚓预测值与实测值之间相关性很好,关系式为y=1.21x-0.13(R2=0.93,n=120)。利用26种土壤中15种PAHs的蚯蚓体内摩尔总量浓度与HPCD提取摩尔总量浓度之间的关系建立模型(Cworm=((CHPCD-0.018)/1.48)0.5-0.239)(R2=0.92,n=26))并结合蚯蚓CBR指标可知,当蚯蚓体内浓度为临界浓度、假设性安全水平、无明显效应和半致死浓度时所对应的HPCD提取摩尔总量分别为0.11 mmol/kg OC,0.37 mmol/kg OC,69 mmol/kg OC和3735 mmol/kgOC；基于HPCD提取与土壤总量比值的正态分布函数,提出能够反映99%的土壤中不同影响水平下PAHs的摩尔总量分别为0.15 mmol/kg OC,0.52 mmol/kg OC,57 mmol/kg OC和5261 mmol/kg OC,从而为土壤中PAHs生态风险指标的建立提供参考。
[Abstract]:Polycyclic aromatic hydrocarbons (Polycyclic Aromatic, Hydrocarbon, PAHs) is a kind of typical hydrophobic organic pollutants, exists widely in the soil, and has teratogenic, carcinogenic and mutagenic effect of hydroxypropyl beta cyclodextrin (Hydroxypropyl- beta -cyclodextrin, HPCD) extraction technology is one of effective assessment of pollutants biological technology, mainly used for to carry out the HPCD ecological risk assessment of pollutants. However, due to the research on the type of pollutant is single, to ignore the pollutants between the effects of chemical diversity, which makes the HPCD extraction mechanism of technology assessment of pollutants biological knowledge is not perfect. This research adopts the comprehensive field investigation of soil HPCD of 15 PAHs inclusion effect of removal effect of performance and earthworm enrichment, respectively from the PAHs occurrence, biological effects of specific aspects of PAHs chemical diversity and HPCD extraction machine in soil PAHs In order to clarify the HPCD extraction system, evaluation mechanism of the bioavailability of PAHs in soils and on this basis to establish a prediction model of HPCD extraction and enrichment of earthworm. By 31 15 PAHs soil total test accelerated solvent extraction technology. Through the double ratio method analysis shows that the highway near the soil PAHs mainly comes from the combustion of fossil fuel chemical plant, coking plant, and farmland near PAHs mainly from oil and coal volatile, combustion, and near the port of PAHs is the main compound pollution. Based on the correlation between soil total PAHs and soil physicochemical properties analysis showed that the total content of PAHs in soil and soil organic carbon content, surface area, soil the clay fraction and sand fraction is related to its relationship to CPAHs=0.48X1+0.33X2+0.36X5+0.20X7 (R2=0.95, n=31) concentration of different kinds of PAHs respectively and soil organic carbon content, specific surface area, Kong Rong, Aperture, size fraction and weathering index (R2=0.54 ~ 0.94, n=31). The results show that there are different types of PAHs in environmental differences. Earthworms on PAHs in different types of soil enrichment ability was studied by earthworm enrichment experiments. The results show that the PAHs correction and BSAF mean respectively in 0.06 + 0.04 (1nP 0.18) ~ (Nap) + 0.10 and 0.12 + 0.05 (1nP + 0.11) - 0.35 (Nap). According to the Statistic Package for SOcial between Science (SPSS) correlation analysis showed that the physicochemical properties of the uncorrected BSAF and soil and PAHs different kinds of PAHs, its relationship to logBSAF=-0.98X3+0.35X5+0.48X8+0.15X9-1.00X11+0.45X15-0.28X16 (R2=0.80, n=390) the correlation factors, respectively, organic carbon content, molecular polarizability, clay fraction, particle fraction, molar volume and biodegradation rate, the molecular polarization of soil organic carbon content and the rate of PAHs to BSAF (Biota -Soil Accumulation Factor. great contribution. The results showed that the difference of earthworm enrichment ability to PAHs is PAHs its physicochemical properties and interaction environment occurrence results. Through the HPCD removal and available experimental study on Extraction Kinetics of evaluation mechanism of PAHs bioavailability in soil HPCD extraction technology, and on this basis to establish a prediction model HPCD extraction and enrichment of earthworms between. Through the SPSS correlation analysis showed that the ratio of BSAF and HPCD extraction and the concentration of PAHs soil total concentration of two together with the soil organic carbon content, biodegradation rate, clay fraction and particle fraction, which changes with the content of organic carbon.HPCD after extraction of soil physicochemical properties with the earthworm bioaccumulation process is similar, the two are the large soil particles into small particles and the specific surface area increased, and the reaction ability of HPCD inclusion inclusion constant and reaction The enrichment ability of earthworm BSAF and PAHs molecular polarizability and molar volume. The results show that the HPCD extraction process can enrichment process simulation of earthworms in the soil in two and may have correlation. 26 kinds of model estimation by the 15 kinds of soil PAHs concentration and HPCD concentration in earthworm extract by using SPSS curve (Cworm= ((CHPCD+k) /a) 0.5+h (R2=0.88) - 0.95, n=26)). 18 kinds of 15 kinds of PAHs in soil and the total concentration of single hybrid, hybrid model is established between earthworm extraction concentration and HPCD concentration, Cworm= ((CHPCD+91.58) /0.0049) 0.5-136.96 (R2=0.96, n=270), were randomly selected to verify 8 prediction models for 4 different types of soil. The results show that the model obtained by earthworms between predicted and measured values have a good correlation, the relation model is y=1.21x-0.13 (R2=0.93, n=120). The use of 26 kinds of 15 kinds of soil earthworm PAHs A model of the relationship between the total body molar concentration and HPCD molar extraction total concentration (Cworm= ((CHPCD-0.018) /1.48) 0.5-0.239) (R2=0.92, n=26)) combined with earthworm CBR index shows that when the earthworm concentration is the critical concentration, hypothetical safety level, corresponding to no obvious effect and semi lethal concentration of HPCD extraction the total molar were 0.11 mmol/kg OC, 0.37 mmol/kg OC, 69 mmol/kg OC and 3735 mmol/kgOC; normal distribution function of HPCD extraction and the amount of soil is proposed based on the ratio of 99% in soil can reflect the different effects of total level of PAHs Moore were 0.15 mmol/kg OC, 0.52 mmol/kg OC, 57 mmol/kg OC and 5261 mmol/kg OC, so as to provide reference for the establishment of soil PAHs ecological risk index.

【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X825

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