石化工业区域甲基硅氧烷的污染特征与环境风险研究

Large amount of chemical assistants were consumed during the petrochemical production processes, in which methyl siloxanes would be released into the environment inevitably and cause ecosystem safety and health problems. Up to now, very few studies have been performed on the issue mentioned above, so it cannot meet the need of environmental impact and ecological risk assessment about methyl siloxanes brought by the petrochemical industry. To address these problems, the occurrences and fates of methyl siloxanes in environmental and biological matrixes will be investigated in/around the petrochemical industry area. The objectives of this research are to investigate (1) the pollution characteristics, identification of sources apportionment, emission fluxes and environmental behaviors of methyl siloxanes in petrochemical industry area, (2) the adverse effects of methyl siloxanes released from the petrochemical industry area on the surface water and farmland soil, and the bioaccumulation, ecological risk and human exposure risks of methyl siloxanes in both environmental systems mentioned above. In summary, our project will contribute to a deep understanding of the behavior and potential risks of methyl siloxanes brought by petrochemical industry, and provide enough scientific evidence for environmental risk assessment and control measures proposing of methyl siloxanes.

石化工业生产过程中会用到大量的化学助剂，其中所含的甲基硅氧烷伴随“三废”不可避免地释放到环境中，给周边区域带来一定的环境负荷，并能引发生态系统的健康与安全问题。然而目前，相关研究报道还相对匮乏，无法满足有关石化工业甲基硅氧烷污染所导致的环境效应和生态风险的评估需要。针对以上问题，本项目拟在完善多种复杂基体中甲基硅氧烷分析方法的基础上，以石化工业区域为研究对象，对该区域甲基硅氧烷的污染进行源解析，估算排放通量并研究其污染特征和环境行为；初步阐明该区域甲基硅氧烷的释放对周边地表水体及农田土壤的环境影响，并研究其生物富集和放大效应以及环境风险和人体暴露风险。项目的完成将为石化工业生产过程中甲基硅氧烷的污染水平评估、管控措施的制定等提供科学依据。

石化工业区作为一个较为严重的甲基硅氧烷污染源会给周边带来一定的环境负荷，并造成生态及人体健康风险，基于此进行了四个方面的基础研究：首先考察了收纳石化工业废水的污水处理厂中甲基硅氧烷的行为归趋，发现污水中甲基硅氧烷浓度更易于分配到污泥中，通过计算各类硅氧烷的泥水分配系数，可知D4-D6的lgKd平均值为3.68-4.80，LMSs的lgKd与链长之间并无明显关系，通过危险商数对甲基硅氧烷可能引起的潜在风险进行评估，结果发现三种环型甲基硅氧烷对水生生物的危害较小；探究了石化区域大气、土壤及水体中甲基硅氧烷的迁移行为研究，证明了环形硅氧烷（D4-D6）具有明显地生物累积效应，其生物累积因子（BAF）为5054-9334；通过对某炼油工业区内炼油行业原材料，产品及有组织排放中甲基硅氧烷的检测等，估算了炼油行业通过原油进入炼化行业甲基硅氧烷的量为1.17×103 kg/day（∑CMSs和∑LMSs分别为3.82×102 kg/day和7.70×102 kg/day），通过各种添加剂引入此行业的甲基硅氧烷的量大致为237 kg/day，即∑CMSs为19.4 kg/day，∑LMSs为222 kg/day，同时测的该工业区有组织排放口检测估算甲基硅氧烷的排放通量为8.23 kg/day。并为了与油田区域对比，研究发现在日常生活中硅氧烷的使用，同样给职业人群及普通人群带来一定暴露风险。项目的完成为石油化工行业过程中甲基硅氧烷的污染水平评估、管控措施的制定等提供科学依据。