基于逸度模型的渭河甘肃段典型PPCPs多介质归趋研究
Multi-media fate of typical PPCPs in Gansu section of Weihe River based on fugacity model
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摘要: 阐明污染物的环境归趋对于其污染控制和生态风险评价具有重要意义,了解污染物在环境中的分布、迁移和转化过程,有助于制定科学有效的污染防治措施。本文通过构建的Ⅲ级多介质逸度模型,结合现场采样分析,研究了克林霉素(CLD)、避蚊胺(DEET)、罗红霉素(ROX)及甲氧嘧啶(TMP)等四种典型药品与个人护理品(PPCPs)在渭河甘肃段环境多介质中的分布及迁移规律。结果表明:(1)4种PPCPs模拟值与实测值相差均在1个数量级内,构建的模型准确性较好;(2)通过模型计算得到环境介质间主要的迁移过程为平流作用及降解作用。平流是水相PPCPs的主要输入及去除途径,水体向悬浮物的扩散及悬浮物向沉积物的沉降是悬浮物相和沉积物相PPCPs主要输入途径。DEET更倾向于在悬浮物中降解且更易由沉积物向水体扩散。CLD及ROX较其他两种PPCPs更倾向由悬浮物向沉积物沉降。TMP在悬浮物及沉积物中都主要依靠降解作用去除。(3)灵敏度研究结果显示,污染物输入浓度、有机碳分配系数、水相平流输入及输出、温度、悬浮物及沉积物中有机碳含量等是影响模型结果的主要参数。(4)不确定分析则表明,整体参数的变化对水体输出结果影响较小,对悬浮物及沉积物影响则较大。本研究较好模拟了典型PPCPs在渭河甘肃段水环境中的多介质归趋,为污染控制和生态风险评估提供了科学依据,有助于优化污染防治措施,加强生态环境与水资源保护。Abstract: Clarifying the environmental fate of pollutants is of great significance to pollution control and ecological risk assessment.Understanding the distribution, migration and transformation process of pollutants in the environment is helpful to formulate scientific and effective pollution prevention measures. The distribution and migration of four typical drugs and personal care products (PPCPs) in environmental multi-media in Gansu section of Weihe River were studied by means of the third-order multi-media fugacity model and field sampling analysis. The results show that: (1) the differences between simulated and measured values of four kinds of PPCPs are within one order of magnitude, and the accuracy of the constructed model is good;(2) the main transport processes between environmental media calculated by the model are advection and degradation. Advection is the main input and removal pathway of PPCPs in aqueous phase, diffusion from water to suspended matter and deposition from suspended matter to sediment are the main input pathways of PPCPs in suspended and sediment phases. DEET tends to degrade in suspension and diffuse more easily from sediment to water. CLD and ROX were more prone to sediment deposition than the other two PPCPs. TMP is mainly removed by degradation in suspended matter and sediment. (3) Sensitivity study results show that input concentration of pollutants, partition coefficient of organic carbon, advection input and output of aqueous phase, temperature, organic carbon content in suspended solids and sediments are the main parameters affecting model results. (4) Uncertainty analysis shows that the change of global parameters has little effect on the output of water body, but has great effect on suspended matter and sediment. This study simulates the multi-medium fate of typical PPCPs in the water environment of Gansu section of Weihe River, which provides scientific basis for pollution control and ecological risk assessment, and is helpful to optimize pollution prevention measures and strengthen ecological environment and water resources protection.