Pollution, sources, and bonding mechanism of mercury in street dust of a subtropical city, southern China
Pollution, sources, and bonding mechanism of mercury in street dust of a subtropical city, southern China
复制标题
南方亚热带城市街道灰尘中汞的污染、来源及结合机制
DOI：
10.1080/10807039.2018.1526631
复制
发表时间：
2019
影响因子：
4.3
通讯作者：
Liang Yan
中科院分区：
文献类型：
--
作者：
Lin Haiying;Zhu Xuetao;Feng Qingge;Guo Ji;a;Sun Xianglin;Liang Yan
城市街道灰尘是城市环境质量的重要指标，而亚热带城市街道灰尘中汞的含量以及汞与灰尘之间的成键反应的研究却十分有限。采用FT-IR和XRD对南宁市街道灰尘的物理性质进行了分析，结果表明，南宁市街道灰尘主要由石英和方解石组成。汞浓度为338.11 ± 222.04 μg/kg（SD，n = 30），与我国部分特大城市汞浓度基本一致。虽然汞的危害商数值表明对人类健康没有致癌风险，但基于高的Igeo和Er，南宁市灰尘的汞污染水平被评估为中度至重度，这仍然需要公众关注。人为来源可能是交通车辆、工业和医院活动排放的废气，以及大量在城市中来回行驶的非机动车，它们使细颗粒物重新悬浮，使汞在空气中富集。XPS分析结果进一步揭示了Hg与卤素、有机物、硫等元素结合或吸附在街道灰尘表面。
Abstract Street dust is a vital pertinent indicator to urban environmental quality, while only limited information is available on Hg from street dust in a subtropical city, as well as the bonding reactions between Hg and dust. In the proposed research, the physical properties of street dust collected from a subtropical city (Nanning) were analyzed with FT-IR and XRD; it was proved that the dust was mainly composed by quartz and calcite. The concentration of Hg was 338.11 ± 222.04 μg/kg (SD, n = 30), which was consistent with that in some mega-cities in China. Although Hazard Quotient values for Hg indicated non-carcinogenic health risk to humans, Hg pollution level of dust in Nanning was assessed to be moderate-heavy based on high Igeo and Er, which still needs public concerns. The anthropogenic source could be exhaust gas discharged from traffic vehicles, industrial and hospital activities, while tremendous amount of non-motor vehicles driving back and forth in the city, which re-suspended fine particles to concentrate Hg in the air. The results of XPS analysis further revealed that Hg combined with halogen, organic matter and S, or was adsorbed on the surface of the street dust.