辽河口湿地典型有机磷酸酯阻燃剂/增塑剂污染特征及其环境行为研究

Organophosphate esters (OPEs) are a group of important chemicals widely used as flame retardants and plasticizers in a variety of products, such as varnishes, polyurethane foams, electronics equipment, upholstery, and textiles. And a number of studies have shown their toxicities to animals and humans; for example, TnBP, TPhP, and TCrP are neurotoxic after chronic exposure, TCEP and TBEP are suspected to be carcinogenic, with observed tumor growth in tissues, TBP is strongly related to sick house syndrome, and TPhP and TDCP were associated with altered hormone levels and a decline of semen quality in male patients. Usually, the OPEs are directly mixed into the materials and are not chemically bonded; therefore, they can be easily released or leached into the surrounding environment from the OP-containing products during manufacture, application, or disposal. Their widespread application has resulted in extensive diffusion and ubiquitous distribution in the environment, for example, in air, wastewater and sludge, surface water, groundwater, sediment and soil. And OPEs were even detected in European Arctic and East Antartic Ice Sheet. However, researches relating with OPEs in estuarine wetland are rarely reported. .The Liaohe estuarine wetland is the biggest coastal wetlands in China and even Asia, which is important in science and ecological environment. Unfortunately, it has suffered from pollution of OPEs. Therefore, this project wants to through scientific sampling to understand the pollution characteristics of OPEs in Liaohe estuarine wetland soils and plants. Combine the dating results of columnar sediments to clarify the chronology characteristics of OPEs in sediments. And analyze the possible pollution sources using the principal component analysis (PCA) / absolute principal component score-multiple linear regression (APCS-MLR) and the stable carbon isotope analysis technology for monomer compounds. Then, we study the existing state of OPEs in wetland soils from Liaohe estuarine using the ASE method and the size and density separation of wetland soils. And the sequential ultrasonic extraction procedure was used to study the speciation of OPEs in wetland soils from Liaohe estuarine, such as the water-soluble fraction, the acid-soluble fraction and the bound fractions. Together with the distribution of OPEs in plants from Liaohe estuarine wetland, we explore the relationships among existing state, speciation and bioavailability of OPEs. Through the research of the release of OPEs in different conditions, such as release time, water-soil ratio, soil size and dry and wet soil, and the speciation and its dynamic change of OPEs under the process of simulated spring tides and semidiurnal tides, we want to explore the transfer mechanism of OPEs between sediments and water interface. Through these studies, we want to provide an important theoretical basis for the ecological risk assessment and pollution prevention and control of OPEs in Liaohe estuarine wetland.

有机磷酸酯（OPEs）以其良好的阻燃、增塑效果广泛应用于塑料等制品，但OPEs具有显著的生物毒性和富集效应。目前，水、土、气等环境介质中均检出OPEs，甚至在北极也有检出，但是河口湿地还鲜见报道。辽河口湿地是我国乃至亚洲最大的暖温带滨海湿地，具有重要的生态价值。因此，本项目以辽河口湿地为研究对象，阐明湿地表层土壤和植物中OPEs的污染特征，结合柱状沉积物的测年结果明确OPEs的时间演化特征，利用主成分分析/绝对主成分得分-多元线性回归模型和单体化合物稳定碳同位素技术识别OPEs的潜在输入源；通过对土壤中OPEs的赋存状态和赋存形态研究，阐明赋存状态、赋存形态与生物有效性的相互关系；通过对干湿交替条件下沉积物-水界面OPEs的分配过程和沉积物中OPEs的赋存形态及其动态变化研究，揭示OPEs在沉积物-水界面的迁移机制；为辽河口湿地生态系统OPEs的生态风险评估以及污染防控提供重要的理论基础。

有机磷酸酯（OPEs）以其良好的阻燃、增塑效果广泛应用于塑料等制品，但由于其具有显著的生物毒性和富集效应，已作为新兴污染物受到广泛关注。本项目以我国乃至亚洲最大的暖温带滨海湿地辽河口湿地为研究对象，开展OPEs相关研究，取得如下结果：（1）辽河口湿地沉积物已遭受OPEs污染，13种OPEs的总浓度为19.5 - 67.0 ng/g；OPEs污染表现出明显的季节性特征，不同水期沉积物中OPEs浓度表现为枯水期>平水期>丰水期；TNBP是最主要的OPEs，约占OPEs总浓度的29.7%；PCA和PMF分析表明辽河口湿地沉积物中OPEs的污染来源也具有季节性特征；沉积物中OPEs的生态风险和健康风险均较低。（2）118 cm长的辽河口潮间带沉积物柱芯各层均检测到了OPEs，浓度为0.45 - 27.0 ng/g；不同沉积时间沉积物中OPEs的含量与环境中OPEs的使用与排放具有较好的对应关系；TBNP是柱芯中相对丰度最高的OPE单体，其次是TBOEP、TCIPP和TIBP；PCA分析表明柱芯中OPEs污染来源可能为大气干湿沉降和污水处理厂的排放；2007至2018年间沉积的沉积物中OPEs通量为46.5 - 105 ng/cm2•y，整个柱芯中的OPE存量估计为1541 ng/cm2。（3）小白菜盆栽实验表明水溶态、有机酸溶态OPEs能被植物或土壤微生物利用、具有生物有效性，而有机结合态OPEs不属于生物有效态；OPEs在不同粒径沉积物中的分布较为均匀，且与TOC含量的相关性较差；沉积物中有机结合态OPEs含量最高，其次是水溶态，有机酸溶态的含量最低，且TOC与赋存形态之间的相关性也较差；湿地植物中OPEs的浓度26.7 - 87.0 ng/g，相关性分析表明水溶态OPEs容易进入到植物中。（4）沉积物中OPEs的释放比例随着释放时间和水土比的增加而增加，并能较快的达到释放平衡；大于63 μm的大粒径沉积物中的OPEs更容易被释放，释放比例约为小粒径的3倍；湿沉积物中OPEs的释放比例显著高于干沉积物；半月潮周期内，沉积物中OPEs总量在不断减少，其中水溶态OPEs减少量最大，其次是有机结合态；日潮周期内，沉积物中OPEs总量也在减少，但减少量显著低于半月潮，且主要是水溶态OPEs减少。本项目研究结果能为辽河口湿地生态系统OPEs生态风险评估与污染防控提供重要的理论基础。