| 鄱阳湖湖口-长江段沉积物中微塑料与重金属污染物的赋存关系 |
| 摘要点击 3252 全文点击 900 投稿时间：2019-07-19 修订日期：2019-08-05 |
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| 中文关键词 鄱阳湖 沉积物 微塑料 重金属形态 赋存关系 |
| 英文关键词 Poyang Lake sediments microplastics heavy metals speciation coexistence |
| 作者 | 单位 | E-mail | | 李文华 | 江西师范大学生命科学学院, 江西省亚热带植物资源保护与利用重点实验室, 南昌 330022 | 1563279443@qq.com | | 简敏菲 | 江西师范大学生命科学学院, 江西省亚热带植物资源保护与利用重点实验室, 南昌 330022
江西师范大学鄱阳湖湿地与流域研究教育部重点实验室, 南昌 330022 | jianminfei0914@163.com | | 刘淑丽 | 江西师范大学生命科学学院, 江西省亚热带植物资源保护与利用重点实验室, 南昌 330022 | | | 江玉梅 | 江西师范大学生命科学学院, 江西省亚热带植物资源保护与利用重点实验室, 南昌 330022 | | | 邓艳彬 | 江西师范大学生命科学学院, 江西省亚热带植物资源保护与利用重点实验室, 南昌 330022 | | | 朱琳 | 江西师范大学生命科学学院, 江西省亚热带植物资源保护与利用重点实验室, 南昌 330022 | |
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| 中文摘要 |
| 重金属是环境中的典型污染物，而微塑料是新型污染物，两者的共存可导致复合污染而存在潜在的生态风险.为探讨鄱阳湖湿地环境中微塑料与重金属的赋存关系，对鄱阳湖湖口-长江段沉积物中微塑料与重金属（Cu、Cd、Pb、Zn和Cr）的含量及其形态特征进行分析.结果表明，沉积物干物质中微塑料丰度范围为356~1452 n·kg-1，平均丰度值达982.33 n·kg-1；通过显微鉴定微塑料形态有碎片类、纤维类和薄膜类，以碎片类为主（48.23%）；而颜色主要以彩色为主；粒径以≤ 1.00mm为主；聚合物成分主要为聚乙烯（PE）、低密度聚乙烯（LDPE）和聚丙烯（PP）.电镜扫描-能谱分析（SEM-EDS）发现，微塑料表面具粗糙、多孔、裂痕和撕裂的特征，并附着多种重金属元素.5种重金属在湿地沉积物中均有不同程度积累，冗余分析表明，沉积物主要理化因素（TOC、pH、EC及粒径）及微塑料赋存对重金属的总含量均有显著影响（P<0.05）；方差分解分析（VPA）显示，理化因素和微塑料对重金属有效态的贡献率分别为37.70%和0.70%，但两者的协同贡献率达49.60%，可导致重金属形态向有效态转化.微塑料可作为重金属的附着载体并将进一步增强重金属污染物的生物有效性，对湿地生态安全构成潜在威胁. |
| 英文摘要 |
| Heavy metals are typical pollutants in the environment and microplastics are relatively newly recognized environmental pollutants, with their coexistence potentially compounding pollution and ecological risks. In this study, we investigate the contents and morphological characteristics of microplastics and heavy metals (Cu, Cd, Pb, Zn, and Cr) in the estuarine sediments of Poyang Lake and the Yangtze River as a means of exploring the relationship between them. The results showed that the abundance of microplastics ranged from 356 n·kg-1 to 1452 n·kg-1, with an average abundance of 982.33 n·kg-1 in the dry sediments. Microplastics were identified as being of three main types:fragments, fibers, and films, whereby fragments were the most dominant type found and accounted for 48.23% of the total microplastics in the sediments. The main color of microplastics in the sediments was chromatic, and the particle size of most microplastics was<1 mm. The major polymer components were polyethylene (PE), low density polyethylene (LDPE), and polyethylene (PP). Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) results indicated that the surfaces of microplastics were rough, porous, cracked, and torn, and that the five heavy metals were found on the surfaces of different microplastics. These heavy metals accumulated to different degrees in the estuarine sediments, and redundancy analysis indicated that environmental factors[including the total organic carbon (TOC), pH, electrical conductivity (EC), and sediment particle size] and the occurrence of microplastics all had significant (P<0.05) effects on the distribution of heavy metal concentrations in sediments. Variation partitioning analysis (VPA) showed that the contribution rates of environmental factors and microplastics to the bioavailability of heavy metals were 37.70% and 0.70% respectively, but the combined effect was 49.60%. We conclude that microplastics in sediments may act as carriers of heavy metals and activate their bioavailability, hence posing a potential threat to the ecological security of estuaries and wetlands. |
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