环渤海地区全氟烷基酸排放与迁移的生态学过程研究
文献类型：学位论文
| 作者 | 王佩 |
| 学位类别 | 博士 |
| 答辩日期 | 2015-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 吕永龙 |
| 关键词 | 全氟烷基酸，氟化工，源解析，污染趋势，生态学过程,perfluoroalkyl acids, fluorochemical industry, source identification, pollution trend, ecological process |
| 其他题名 | Ecological processes of perfluoroalkyl acids emitted from fluorochemical industry in Bohai coastal Region |
| 学位专业 | 生态学 |
| 中文摘要 | 自2000年全氟化合物（PFASs）主要生产商美国3M公司停止生产全氟辛烷磺酸（PFOS）类产品后，2002年3M公司开发出PFOS的短链替代物全氟丁烷磺酸（PFBS），并继续生产全氟丁酸（PFBA）作为对全氟辛酸（PFOA）等长链同系物的替代物，同时逐步将产能向包括中国在内的其他国家转移。PFBS和 PFBA具有比其长链同系物更低的毒性，可以在很多方面有效替代其长链同系物的应用，但是PFOA在氟聚合物行业仍然有不可替代的应用。近年来发达国家对 PFOA生产和排放的严格限制也使得 PFOA的产能向外转移。我国氟化工行业在近年来迅猛发展，与这种产能转移密切相关。然而这些氟化工企业的排放特征及其对周边环境的影响在很大程度上是未知的。本研究选取环渤海地区为典型研究区，依据环渤海北部和南部不同的产业发展模式分别进行研究。通过遥感数据结合 GIS空间分析获得区域河流的精确信息，按照均匀布点并在重点区域加密布点的原则，系统采集水、沉积物、土壤和水生植物等样品，优化提取分析方法快速准确地分析 PFASs的浓度，重点分析具有高水溶性及显著排放水平的全氟烷基酸（PFAAs），在此基础上辨识PFAAs不同来源的贡献水平和排放强度，针对氟化工源进一步解析其排放特征和污染趋势等生态学过程，探讨氟化工行业PFAAs高排放对饮用水系统的潜在风险和对水生植物分布和富集的效应。 在环渤海北部，首先在课题组 2008年研究的基础上选择辽东湾地区，探讨其表层土壤中 PFASs的分布水平及潜在来源，并引入物料平衡法（Mass Balance）解析土壤中不同形态氟元素的分布特征。结果表明，辽东湾地区土壤中的PFASs以 PFOA等长链全氟羧酸（PFCAs）和PFOS为主，也有前驱物检出。土壤中PFASs对可提取有机氟（EOF）的贡献仅有0.5%，表明土壤中还有很大的未知有机氟成分，这些成分中可能包含有 PFASs的前驱物。而 EOF又仅占土壤总氟（TF）含量的 0.02%，表明土壤中的氟元素主要以无机氟和不可提取有机氟形态存在。由于在 2008年之前，我国的 PFAAs生产和排放以长链为主，长链PFAAs及其前驱物易随大气进行远距离传输并通过沉降进入土壤等环境介质。实地调查发现，各环境介质中 PFAAs浓度较高的大凌河流域，其上游有两座氟化工园区是 PFAAs的潜在直接排放源。基于长链 PFAAs大气传输理论可以得出，辽东湾地区表层土壤中 PFAAs主要来源于两座氟化工园区。 本研究选择大凌河流域研究新兴氟化工产业的PFAAs排放特征及其在水环境中的生态学过程。通过流域整体布点，进一步确定大凌河支流细河上的两座氟化工园区为 PFAAs的主要来源，其 PFAAs排放以 PFBS（最高浓度 2.90 µg/L）和 PFBA（最高浓度 1.35 µg/L）为主，其次是 PFOA（最高浓度 0.35 µg/L），PFAAs的主要水系传输通道为工业园区下游至入海口。年度趋势（2011-2014年）表明PFBS、PFBA和PFOA一直是主要的PFAAs排放种类，其中PFBS和PFBA的浓度水平在 2012年有所下降，在2012-2014年则呈上升趋势，PFBA比PFBS的上升趋势更显著；PFOA的浓度水平从 2011-2013呈上升趋势，在 2014年又有所下降。季节性趋势（2013年）作为对年度趋势的补充，结果表明，三种主要 PFAAs的在夏秋季节的浓度水平要显著高于春冬季节，表明企业在夏秋季节的生产活动更多；同时，PFOS在某些情况下仍然有生产。在空间分布上，年度趋势和季节性趋势都表明园区一（海州园区）的排放水平一直显著高于园区二（伊吗图园区）。本研究中进一步选择园区二研究 PFAAs对饮用水系统的潜在影响。结果表明，园区一下游村庄的地下水中 PFOA水平高于几乎所有的现行水质标准值，应禁止饮用，PFBA在地下水中的分布最广泛，但浓度水平未超过水质标准值，PFBS的地下水中浓度相对较低，与河水中趋势不同。自来水中的 PFAAs浓度水平较低，可以安全饮用。 对环渤海南部主要入渤海河流中 PFAAs的整体研究表明，PFOA占据主导位置，其次是短链 PFCAs，小清河流域 PFAAs的浓度水平显著高于其他河流。主成分分析（PCA）表明，所有河流中的 PFAAs具有相似的来源。其中入海口处 PFAAs水平结合渤海的潮汐和海流特征分析，表明PFAAs由河流入海后可以在近海海岸进行远距离扩散。通过对研究区域内氟化工产业布局的分析，发现小清河流域有大量的氟化工企业，具有很高的氟聚合物产能，而PFOA是多种氟聚合物生产过程中的加工助剂，这表明氟化工企业是小清河流域高水平PFOA的潜在主要来源。 本研究进一步对小清河流域进行加密布点分析，确认其中一个氟化工企业（F1）的贡献要显著高于其他氟化工企业和其他来源，F1是一家高度自给自足的企业，既有很高的应用 PFOA作为加工助剂生产氟聚合物的产能，也直接生产 PFOA等PFAAs，具有典型的大型集中式氟化工产业特征。2013年在其排污口下游中检测到的 PFAAs浓度高达1.06 mg/L（通量为 174 kg/d），含 0.97 mg/L的 PFOA（通量为 159 kg/d），其对水环境的影响一直持续到小清河入海口。2013年入海口处 PFOA浓度是2011年的4倍，通量则是2011年的10倍，显示了PFOA排放的快速增长趋势，这种趋势与F1 2013年并购另一家大型氟聚合物企业有关。2014年的季节性监测结果表明，F1对其排污河道及小清河下游高强度的 PFAAs排放是持续的，对水生生态系统具有潜在的重要影响。本研究选择水生植物，研究其在 PFAAs不同污染区的分布和对PFAAs的富集效应。调查发现，小清河流域主要有三种水生植物，分别是丝藻、金鱼藻和轮叶黑藻。其中金鱼藻分布最为广泛，包括 F1的排污河道、排污河道汇入小清河处的上游和下游都有分布，丝藻主要分布于 F1排污河道，而轮叶黑藻主要分布于排污河道汇入小清河处的上游。对PFAAs的富集方面，在排污口下游点处，金鱼藻对PFOA的富集浓度高达3.77 µg/g，与水体中的高浓度 PFOA一致，但对C4-C7PFCAs的富集浓度与水体中的浓度不同，表明金鱼藻对PFCAs的富集与PFCAs的碳链长度不是呈正相关关系，这种趋势在丝藻中也有发现。金鱼藻对PFOA的富集能力是丝藻的 4.6倍，对C4-C7的富集能力比丝藻更高。金鱼藻的广泛分布和对 PFAAs显著的富集能力表明其可以作为一种潜在的PFAAs指示水生植物。 综上所述，环渤海北部大凌河流域新兴氟化工产业和南部小清河流域大型集中式氟化工产业在 PFAAs排放及其对水生态环境的影响，既有特性，又有共性。大凌河流域 PFAAs排放以短链替代物 C4 PFBS和 C4 PFBA为主，以 C8PFOA为辅；小清河流域 PFAAs排放以C8 PFOA为主，C4-C7 PFCAs为辅。排放水平上小清河流域要远高于大凌河流域，但是小清河流域氟化工企业已基本成型，而大凌河流域的氟化工企业则绝大部分还处于规划建设中，未来发展空间更大。本研究中所检测到的PFAAs浓度水平高于目前全球绝大多数的研究，这种高浓度对 PFAAs的环境归趋也产生了新的趋势，在对大凌河流域和小清河流域高污染区 PFAAs的水-沉积物分配的研究中发现，对比与低污染区，C4-C8PFCAs的水-沉积物分配系数（log KOC）明显降低，表明沉积物对 PFAAs的吸附能力是有限的，未来应加强水介质中 PFAAs的研究。由于 PFOA毒性和受关注度都要显著高于 PFBS和 PFBA，未来环渤海地区对 PFAAs人体健康和水生生态系统健康的研究应更多的聚焦于小清河流域，同时对大凌河流域氟化工行业的发展保持密切关注。 |
| 英文摘要 | After the global major fluoropolymer manufacturer ceased the production of perfluorooctane sulfonic acid (PFOS)and related substances in 2000,perfluorobutane sulfonic acid (PFBS) was developed in 2002 as the ubstitude, and perfluorobutanoic acid (PFBA) has been produced to partly replace perfluorooctanoic acid (PFOA) and higher homologues uses. However, as processing aid during the production of many fluoropolymers, PFOA is still in huge demand.And restrictions on production and emission of PFOA in some developed countries have led to production shift of PFOA as well as PFBS and PFBA to some emerging economies including China. The fast development of fluorochemical industry in China in recent years is mainly due to the production shift, but subsquences of potential high perfluoroalkyl substances (PFASs) emission to the local environment are largely unknown. In this study, we choose the Bohai coastal region, which is one of the most developed area in China, to conduct a systematic research. The study area was devided into the Northern and Southern parts based on the different mode of fluorochemical industry. Detailed remote sensing and geographical data were used for research design, and samples including water, sediment, soil and aquatic plants were collected and analyzed for PFASs, mostly perfluoroalkyl acids (PFAAs) based on our modified methods. The main aim of this study is to identify the levels and contributions of main PFAAs from various sources, then with focusing on the fluorochemical industry to further analyze their emission characteristics and ecological processes, and potential health risk to local drinking water system and bioaccumulation in aquatic plants. The coastal area of Liaodong Bay in Northern part of Bohai sea was choosen to identify the sources of relatively high PFASs in soil. Results indicated that long-chain perfluoroalkyl carboxylic acids (PFCAs) and PFOS are dominant. Mass balance method was introduced to quantify different forms of fluorine in soil as an indicator for source analysis. PFASs only accounted for 0.5% of Extractable Organic Fluorine (EOF), which indicated that large amount of unidentified organic fluorine exist in soil that might act as the precursors of PFAAs. While EOF only accounted for 0.02% of Total Fluorine (TF). Considering the main PFAAs produced in China before 2008 were in long-chain form that would more easily be emitted to air and deposited to local environment through atmospheric transportation and wet or dry deposition, it can be concluded that the PFAAs detected in the soil mainly came from two fluorochemical industry parks located in the Daling River Basin. The two fluorochemical industry parks in Daling River Basin were newly emerged and developed fast, but still largely under construction. Detailed investigation on the whole Daling River Basin further demonstrated that the two parks were the main sources of PFAAs, dominated by PFBS, PFBA and PFOA, with the highest concentrations of 2.90 µg/L, 1.35 µg/L and 0.35 µg/L, respectively. The main transportation route of PFAAs was selected from the downstream of the two parks to the estuary of the Daling River for further ecological processes research. Annual monitoring from 2011 to 2014 indicated that PFBS, PFBA and PFOA have always been the dominant PFAAs with different trends. PFBS and PFBA both decreased from 2011-2012 and then increased from 2012-2014, the increasing trend was higher for PFBA than PFBS; PFOA firstly increased from 2011-2013 and then decreased in 2014. As a supplement, seasonal monitoring in 2013 indicated that concentrations of all PFAAs were higher in summer and autumn than in spring and winter, implying more production activity in warmer days. Meanwhile, PFOS could be produced in some occasions. Spatial distribution of PFAAs in both annual and seasonal monitoring showed that emissions from Park 1 had always been higher than that from Park 2. So drinking water in villages around Park 1 were taken for risk assessment. Results indicated that groundwater in the villages downstream of Park 1 contained high levels of PFOA that exceeded most current drinking water criteria,and should be taken out of daily use. PFBA was mostly distributed in groundwater around Park 1 while PFBS presented relatively low levels, which was different from that in river water. PFAAs levels in tap water indicated low health risk. PFOA was the dominant PFAAs in South Bohai coastal rivers, followed by short-chain PFCAs, the highest concentrations of PFAAs were identified in the Xiaoqing River. Principle Componant Analysis (PCA) indicated the similar sources of PFAAs in the all rivers. Analysis on the influence of tide and waves in Bohai Sea implied that PFAAs could be transported long distances along the shore among the estuary of different rivers. Investigation on the distribution of fluorochemical industry in the study area showed that there are several fluorochemical manufacturers located in the Xiaoqing River Basin, with very high production capacity of fluoropolymers that would use PFOA as processing acids, which could be the main source of PFOA detected in the rivers. We further conducted detailed research in the Xiaoqing River Basin, and confirm one fluorochemical manufacturer (F1) as the dominant source of PFAAs emission. F1 is a highly self-sufficient mega fluorochemical manufacturer that owns very high capacity of both fluopolymers that use PFOA as processing aids and PFAAs themselves. Concentration of PFAAs in the river water downstream of F1’s effluent was 1.06 mg/L with mass load of 174 kg/d, including 0.97 mg/L of PFOA with mass load of 159 kg/d. High levels of PFAAs were kept to the estuary of the Xiaoqing River, and concentrations of PFOA increased 3 times from 2011 to 2013,while mass loads of PFOA increased 9 times from 2011 to 2013. The great increasing trend was due to that F1 purchased another fluorochemical manufacturer in the beginning of 2013. Seasonal monitoring of PFAAs in the downstream of F1 in 2014 indicated that F1 emitted high levels of PFAAs consistently. There are three main aquatic plants in the the Xiaoqing River including Ulothrix, Ceratophyllum demersum L. and Hydrilla verticillata. Ceratophyllum demersum L. distributed most widely in F1’s sewage-received river, and the upstream and downstream of the confluence point in the Xiaoqing River; Ulothrix mainly distributed in F1’s sewage-received river and Hydrilla verticillata mainly distributed in the upstream of the confluence point. In the downstream of F1, Ceratophyllum demersum L.accumulated PFOA in concentrations of 3.77 µg/g, which is consistent with the highest PFOA level in water. But the accumulated concentrations of C4-C7 PFCAs were quite different from the PFAAs profiles in water. This indicated that the bioaccumulation potential of PFAAs in Ceratophyllum demersum L. was not in direct propotion with the concentrations in water. The trend was also found in Ulothrix. Concentrations of PFOA in Ceratophyllum demersum L. were 4.6-fold than in Ulothrix, and even higher for C4-C7 PFCAs. The wide distribution and high bioconcentration of PFAAs in Ceratophyllum demersum L. indicated that it could be used as a potential indicator for PFAAs pollution. Above all, the newly emerged fluorochemical industry in the Daling River Basin was characterized by the emissions of C4 PFBS and C4 PFBA, followed by C8 PFOA, while the highly self-sufficient mega fluorochemical industry in the Xiaoqing River was characterized by the emissions of C8 PFOA, followed by C4-C7 PFCAs. Levels of PFAAs in the Xiaoqing River were much higher than those in the Daling River. However, the production capacity in the Xiaoqing River is already approaching its design capacity, while most production facilities in the Daling River are still under construction or planned. Furthermore, the staggeringly high levels of PFAAs detected in both areas also led to new findings in the partitioning coefficients between water and sediment (log KOC). Compared with low PFAAs levels in water,log KOC for C4-C8 PFCAs decreased in high PFAAs levels in water. This indicated that the sorption of C4-C8 PFAAs from water to sediment is limited, and future studies on these PFAAs should be more focused on aquaeous matrix. Considering the toxicity and health concern of C8 PFOA are much higher than C4 PFBS and PFBA, future studies on the human and ecosystem health of PFAAs should pay more attention to the Xiaoqing River Basin, and stay close on the development of fluorochemical industry in the Daling River Basin. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/34438]  |
| 专题 | 生态环境研究中心_城市与区域生态国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 王佩. 环渤海地区全氟烷基酸排放与迁移的生态学过程研究[D]. 北京. 中国科学院研究生院. 2015. |
入库方式： OAI收割
来源：生态环境研究中心
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