| 摘要: |
| 根据日照近海13个站位表层沉积物粒度和重金属含量测试结果，分析了研究区表层沉积物粒度和重金属含量分布特征，采用地累积指数法和潜在生态风险指数法评估了研究区重金属污染状况和潜在生态风险，探讨了重金属的来源和控制因素。结果表明，研究区表层沉积物可分为粉砂、粉砂质砂、砂质粉砂等3种类型，沉积物类型主要呈大致平行岸线的条带状分布，由岸向海依次为粉砂砂质粉砂粉砂质砂。研究区表层沉积物中Cr、Zn、Pb、As、Cu、Cd、Hg等重金属的平均含量由高到低依次为45.5、21.8、16.4、8.5、4.8、0.113、0.11 μg/g。从空间分布特征来看，Cr、Cu、Zn和Pb高值区主要出现在付疃河口近岸和研究区中西部海域，Cd和As高值区位于研究区中东部海域。污染状况评估显示，Cr、Cu、Zn、As未出现污染；Cd轻度污染，个别站位达到中度污染，Hg、Pb部分站位呈轻度污染。潜在生态风险等级依次为：Cd＞Hg＞Cu＞As＞Pb＞Cr＞Zn，其中Cd和Hg表现为中生态风险，个别站位Cd为高风险危害。表层沉积物中Cu、Cr、Zn、Hg和Pb元素主要来源于陆源细粒物质的输入，Cd和As元素可能来源于钢铁冶炼、煤炭燃烧、农药、化肥以及海水养殖等。研究区表层沉积物中重金属空间分布主要受物源控制。 |
| 关键词: 海洋化学 表层沉积物 重金属 污染评价 影响因素 近海 日照 |
| DOI：10.3969/J.ISSN.2095-4972.2020.04.007 |
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| 基金项目:国家自然科学基金资助项目（41776059） |
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| Distribution characteristics and ecological risk assessment of heavy metals in surface sediments of Rizhao offshore waters |
| QI Luyang,JIANG Shenghui |
| (College of Marine Geosciences, Ocean University of China, Qingdao 266100, China;College of Marine Geosciences, Ocean University of China, Qingdao 266100, China; Key Laboratory of Submarine Geosciences and Prospecting Techniques, MOE, Ocean University of China, Qingdao 266100, China) |
| Abstract: |
| Based on 13 surface sediment samples collected from the offshore waters of Rizhao, the grain size and distribution characteristics of heavy metals were analyzed. The pollution indexes and potential ecological risk indexes were used to assess the pollution level and potential harmful effects of heavy metals to explore the origin of heavy metals and controlling factors. Results show that surface sediments can be grouped into 3 types, i.e. silt, sandy silt and silty sand. And they distribute roughly along the coastline with zonation of silty sand, sandy silt and silt in consequence toward the sea. The averaged contents of Cr, Zn, Pb, As, Cu, Cd and Hg in the sediments from high to low are 45.5, 21.8, 16.4, 8.5, 4.8, 0.113 and 0.11 μg/g, respectively. High value area of Cr, Cu, Zn and Pb distributes mainly in the nearshore waters of Futuan Estuary and in the mid-west of study area and high value area of Cd and As in the mid-eastern of the study area. The assessment shows little pollution of Cr, Cu, Zn and As and mild pollution of Cd in the study area except for some moderately polluted sites. Hg and Pb are lightly polluted at some sites. The potential ecological risk level is in order of Cd, Hg, Cu, As, Pb, Cr and Zn. Among them, Cd and Hg are medium ecological risk. Cd is of high-risk hazard at particular sites. Cu, Cr, Zn, Hg and Pb may come from the input of terrestrial fine materials while Cd and As from iron and steel smelting, coal combustion, pesticide and fertilizer application and mariculture activities etc. The spatial distribution of heavy metals in the surface sediments of the study area is mainly controlled by provenance. |
| Key words: marine chemistry surface sediments heavy metal pollution assessment affecting factor offshore waters Rizhao |
