基于逸度模型研究深圳典型POPs环境行为与风险

发布时间：2019-04-02 01:52

【摘要】：持久性有机污染物(Persistent Organic Pollutants,POPs)是人工合成的一类有机化合物,稳定的物理化学性质使其具有生物蓄积性、环境持久性和高毒性等特征,由于长期大量的使用现已存在于全球范围的各种环境介质中。监测环境中POPs浓度水平是早期预防POPs危害最有效的手段。但对于新型的POPs和一些检测费用十分高昂的POPs,由于监测手段的不成熟和设备资金的限制很难对它们在环境相中的浓度进行常规测量。Donald Mackay提出的逸度模型可以仅靠研究区域的环境参数和化合物的物理化学参数模拟计算出POPs在环境各介质的浓度水平,从而揭示化合物的迁移和归趋行为,是研究环境介质中POPs的一种有效手段。本研究基于逸度方法,以深圳地区为研究区域,选取大气、水体、土壤和沉积物四个环境相,构建了和现实环境相耦合的Level III逸度模型,并对全氟辛烷磺酸(perfluorooctane sulfonate,PFOS)、全氟辛酸(perfluorooctanoic acid,PFOA)和二VA英(PCDD/Fs)3种典型POPs在深圳地区的浓度水平、环境行为、长距离迁移潜力和生态风险进行了研究,以期为典型POPs在深圳地区的风险评估及区域环境污染治理提供科学依据。本研究还对深圳大气中的PFOS和PFOA的浓度进行了实测,用来验证模型的可靠性。主要研究结果如下:(1)模拟计算了PFOS、PFOA和二VA英在深圳地区大气、水体、土壤和沉积物中的浓度水平和介质间的迁移通量,与当地的实测数据吻合较好。深圳地区PFOS和PFOA主要来源于上风向地区和上游河流,最主要的迁出途径是随河流迁出;二VA英的主要来源途径是本地源的排放和上风向地区的输入,主要的输出途径是随大气平流输出。(2)模型输入参数的灵敏度分析结果显示,对3种POPs浓度影响最大的3个输入参数是大气、水体平流输入速率和有机碳分配系数KOC。此外,温度、水溶解度和降水速率对POPs的浓度也有一定的影响。大气排放速率则对二VA英浓度的影响较大,对PFOS和PFOA的影响较小。模型输出结果的不确定性分析显示,3种POPs浓度的变异系数在流体相中较低而在固相中较高。(3)根据本研究实测数据评估了PFOS和PFOA的暴露风险,结果显示暴露对人体健康不具即时危害。利用TaPL3模型评价了3种典型POPs在深圳地区的长距离迁移潜力,结果显示3种POPs无论是排放到大气还是水体,二VA英在环境中的总持久性和迁移距离都相对较小。基于垃圾焚烧量对深圳大气中二VA英的浓度进行预测,发现当深圳市每日垃圾焚烧量达到50000吨时,大气中二VA英的浓度水平将会超过日本规定的限值(600 fg I-TEQ·m-3),对市民的健康产生威胁。
[Abstract]:Persistent organic pollutant (Persistent Organic Pollutants,POPs) is a kind of synthetic organic compound, which is characterized by its stable physical and chemical properties, such as bioaccumulation, environmental persistence and high toxicity. Because of the long-term use of a large number of existing in the global range of environmental media. Monitoring the concentration of POPs in the environment is the most effective way to prevent the harm of POPs in the early stage. But for new types of POPs and some expensive POPs, tests, Due to the immaturity of monitoring tools and the limitation of equipment funds, it is difficult to measure their concentrations in the environmental phase. Donald Mackay's fugacity model can rely solely on the environmental parameters of the study area and the physical and chemical parameters of the compounds. The concentration level of POPs in various media of the environment is calculated by numerical simulation. Thus, it is an effective means to study POPs in environmental media by revealing the migration and normalization behavior of compounds. Based on fugacity method, four environmental phases, atmosphere, water, soil and sediment, were selected to construct the Level III fugacity model coupled with the real environment and perfluorooctane sulfonic acid (perfluorooctane sulfonate,PFOS). The concentrations, environmental behavior, long-range migration potential and ecological risk of perfluorooctanoic acid (perfluorooctanoic acid,PFOA) and diVA (PCDD/Fs) in Shenzhen were studied. In order to provide scientific basis for risk assessment and regional environmental pollution control of typical POPs in Shenzhen. The concentrations of PFOS and PFOA in Shenzhen atmosphere were measured to verify the reliability of the model. The main results are as follows: (1) the concentrations and transport fluxes of PFOS,PFOA and diVA in the atmosphere, water, soil and sediment in Shenzhen area are simulated and calculated, which is in good agreement with the local measured data. In Shenzhen, PFOS and PFOA mainly come from the upwind and upstream rivers, and the most important way out of Shenzhen is to move out with the river. (2) the sensitivity analysis results of the input parameters of the model show that the main sources are the emission from the local source and the input from the upwind region, and the main output path is with the atmospheric advection. (2) the sensitivity analysis results of the input parameters of the model show that the main output path is with atmospheric advection. The three input parameters which have the greatest influence on the three POPs concentrations are atmosphere, water advection input rate and organic carbon partition coefficient (KOC.). In addition, temperature, water solubility and precipitation rate also have some effects on the concentration of POPs. The atmospheric emission rate has a great effect on the concentration of diVA-E, but has little effect on PFOS and PFOA. The uncertainty analysis of the output of the model shows that the coefficients of variation of the three POPs concentrations are lower in the fluid phase but higher in the solid phase. (3) the exposure risks of PFOS and PFOA are evaluated based on the measured data in this study. The results showed that exposure had no immediate harm to human health. The TaPL3 model was used to evaluate the long-range migration potential of three typical POPs species in Shenzhen. The results show that the total persistence and migration distance of two-VA-UK in the environment are relatively small regardless of whether they are discharged into the atmosphere or the water body. Based on the prediction of the concentration of diVA-E in the atmosphere of Shenzhen City, it is found that the concentration level of diVA-E in the atmosphere will exceed the limit specified by Japan (600 fg I-TEQ 路m-3) when the daily amount of waste incineration in Shenzhen reaches 50000 tons. Pose a threat to the health of citizens.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X592

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