• 关键词：溴系阻燃剂  电子垃圾  贵屿  持久性有机污染物  新型污染物

• 基金项目：国家自然科学基金（No.41273002）；广东省自然科学基金（No.2018A030313904）；广州市科技计划项目（No.201707020028）；广东省科技项目（No.2017B030314057）

• 宋爱民
• 1. 中国科学院广州地球化学研究所, 有机地球化学国家重点实验室和广东省环境资源利用与保护重点实验室, 广州 510640;2. 中国科学院大学, 北京 100049

• 李会茹
• 1. 华南师范大学, 环境研究院, 广东省化学品污染与环境安全重点实验室&环境理论化学教育部重点实验室, 广州 510006;2. 华南师范大学, 环境学院, 广州 510006

• 刘合欢
• 1. 中国科学院广州地球化学研究所, 有机地球化学国家重点实验室和广东省环境资源利用与保护重点实验室, 广州 510640;2. 中国科学院大学, 北京 100049

• 李阳
• 长江大学, 资源与环境学院, 武汉 430100

• 盛国英
• 中国科学院广州地球化学研究所, 有机地球化学国家重点实验室和广东省环境资源利用与保护重点实验室, 广州 510640

• 彭平安
• 1. 中国科学院广州地球化学研究所, 有机地球化学国家重点实验室和广东省环境资源利用与保护重点实验室, 广州 510640;2. 中国科学院大学, 北京 100049

• 摘要：为考察贵屿电子垃圾拆解区污染沿水体向下游的迁移行为和影响，本文对练江贵屿段及其上下游表层沉积物进行了系统采样和多溴联苯醚（PBDEs）分析，并对其污染来源和潜在生态风险进行了探讨.结果表明：PBDEs在练江上下游沉积物中普遍存在（检出率100%），在贵屿上游浓度较低（10.2~2120 ng·g^-1），进入贵屿段急剧升高（7470~193000 ng·g^-1），至贵屿下游后有所起伏但整体下降（734~11300 ng·g^-1）.练江的PBDEs污染主要来自于沿途排放，贵屿电子垃圾拆解业是其中最大的污染排放源.贵屿下游沉积物的PBDEs浓度比上游高约一个数量级，说明贵屿高浓度的PBDEs污染可沿水体迁移至下游.主因子分析结果表明练江沉积物中的PBDEs污染存在3种模式，上游和下游主要支流（贵屿支流除外）呈现Deca-BDE污染模式（BDE-209为绝对优势单体），这是我国沉积物中PBDEs的典型污染模式，可视为练江沉积物中PBDEs污染的背景模式；贵屿则呈现出两种特异模式：Penta-BDE模式（优势单体BDE-47&-99）和Deca-BDE脱溴降解模式（以BDE-197为主，其次是-209），这分别与贵屿地区的电路板拆解和塑料的高温处理方式（烘烤、焚烧、熔融等）有关；贵屿下游支流和主干道样品中的PBDEs呈现与贵屿相似但多种模式共存的特征，进一步证实贵屿的PBDEs污染已沿水体迁移至下游并影响其PBDEs组成特征.练江上游和下游主要支流（贵屿支流除外）PBDEs的风险商值（HQ）均<1，表明生态风险可接受；贵屿段PBDEs的HQ值均>1，最高达63.9，存在严重生态风险；受贵屿污染迁移影响，贵屿下游支流及部分练江主干道样品的HQ值也>1，为PBDEs污染高风险区；Penta-BDEs（三-五溴代BDEs）为HQ值主要贡献污染物，其次是Hexa-BDEs和Deca-BDE.鉴于PBDEs具有环境持久性且在贵屿段的沉积通量高达（477±648）t（贵屿下游为（152±169）t），其在贵屿及其下游20 km以内的污染急需开展进一步调查并采取相应的污染治理和修复措施.

• Abstract：Although severe environmental pollution caused by the release of polybrominated diphenyl ethers (PBDEs) from inappropriate e-waste recycling activities has been widely reported in Guiyu, scarce attention was paid to the migration and potential harm of these PBDEs on Guiyu downstream. In this study, 22 surface sediment samples were collected from the origin to the mouth of the Lian River encompassing Guiyu, and the contents of PBDEs in these samples were analyzed. The results showed that PBDEs were detected in all of the samples. They demonstrated low levels at the origin (10.2 ng·g^-1), increased along the river (92.6~2120 ng·g^-1), then rose dramatically to 7470~193000 ng·g^-1 in Guiyu, but dropped substantially upon exiting Guiyu, and finally exhibited a fluctulation but overall declining trend toward the river's estuary (734~11300 ng·g^-1). This trend suggests that the PBDEs in the Lian River arose predominantly from local discharges along the river, and Guiyu e-waste recycling activities were the dominant emission source. The PBDEs in the sediments from Guiyu downstream were one order of magnitude greater than those in the sediments from Guiyu upstream, indicating that the PBDEs in Guiyu might have migrated downstream. The results of principle factor analysis show three patterns of PBDE pollution in the Lian River: ① Deca-BDE (dominated by BDE-209) is the main pollutant in the sediments from Guiyu upstream and some downstream tributaries. This is a typical PBDE profile found in China, and therefore is regarded as the background PBDE in the Lian River; ② Penta-BDE (profound congeners BDE-47&-99) and ③ Deca-BDE debromination products (dominated by BDE-197&-209) are present in the Guiyu samples. The latter two patterns were attributed to the local circuit board recycling and high-temp plastic processing activities (e.g. oven-roasting, open-burning, melting, etc.), respectively. The PBDEs in the sediments from Guiyu downstream exhibited the three patterns, which further confirms the migration and influence of the PBDEs in Guiyu on downstream areas. The hazard quotients (HQs) of the Lian River upstream and most downstream tributaries were lower than 1, suggesting that the ecological risk is in the acceptable range. However, the HQs of Guiyu sediments were greater than 1 (1.09~63.9), indicating that there are serious and unacceptable risks. Moreover, the migration of PBDEs from Guiyu had turned some of its downstream areas into high-risk regions (HQs: 1.34~3.38). Penta-BDEs were the dominant HQ contributor, followed by Hexa-BDEs and Deca-BDE. Considering the persistence of PBDEs in environments and their high HQs and masses in Guiyu ((477±169) t) and downstream ((152±169) t), further investigation and appropriate remediation in Guiyu to its 20 km downstream are quite necessary.

• Key words：brominated flame retardants  e-waste  Guiyu  persistent organic pollutants  emerging contaminants

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