热带地理 ›› 2021, Vol. 41 ›› Issue (2): 398-409.doi: 10.13284/j.cnki.rddl.003320

• 自然地理 • 上一篇    

湛江观海长廊红树林土壤-植物体系重金属富集与迁移规律

李振良1(), 谢群2(), 曾珍2, 张际标1,5, 冯宇明1, 赖勇平3, 林玲玲4   

  1. 1.广东海洋大学 化学与环境学院,湛江 524088
    2.广东海洋大学 分析测试中心,湛江 524088
    3.广东海洋大学 管理学院,湛江 524088
    4.广东海洋大学 食品与科学技术学院,湛江 524088
    5.南方海洋科学与工程广东省实验室,湛江 524088
  • 收稿日期:2020-07-11 修回日期:2020-10-14 出版日期:2021-04-27 发布日期:2021-04-27
  • 通讯作者: 谢群 E-mail:lzl9904130613@163.com;Xieq@gdou.edu.cn
  • 作者简介:李振良(1999—),男,广东湛江人,本科,主要从事生态环境化学研究,(E-mail)lzl9904130613@163.com
  • 基金资助:
    广东海洋大学冲一流项目(231419018);创新强校工程项目(230420021);南方海洋科学与工程广东省实验室(湛江)资助项目(ZJW-2019-08)

Enrichment and Migration of Heavy Metals in Mangrove Soil-Plant System from Sea Promenade in Zhanjiang

Zhenliang Li1(), Qun Xie2(), Zhen Zeng2, Jibiao Zhang1,5, Yuming Feng1, Yongping Lai3, Lingling Lin4   

  1. 1.College of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, China
    2.Analytical and Testing Center, Guangdong Ocean University, Zhanjiang 524088, China
    3.College of Management, Guangdong Ocean University, Zhanjiang 524088, China
    4.College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China
    5.Southern Laboratory of Ocean Science and Engineering, Zhanjiang 524088, China
  • Received:2020-07-11 Revised:2020-10-14 Online:2021-04-27 Published:2021-04-27
  • Contact: Qun Xie E-mail:lzl9904130613@163.com;Xieq@gdou.edu.cn

摘要:

选取湛江市霞山区观海长廊红树林湿地为研究区域,运用电感耦合等离子体质谱仪(ICP-MS)测定红树林表层土壤及红树植物根、枝、叶中重金属(铜Cu、锌Zn、铅Pb、镉Cd、铬Cr、镍Ni、砷As)的质量分数;运用Hakanson潜在生态风险指数评估红树林土壤的重金属污染风险水平,结合相关性分析和聚类分析探讨重金属的影响因素及来源;应用生物富集系数(BCF)、转运系数(TF)分析重金属在土壤-植物中的富集和迁移能力。结果表明:1)研究区表层土壤7种重金属分布规律为Zn(57.48 mg/kg)>Cr(29.31 mg/kg)>Pb(19.23 mg/kg)>Cu(16.62 mg/kg)>Ni(8.18 mg/kg)>As(6.00 mg/kg)>Cd(0.20 mg/kg)。7种元素平均质量分数均未超过《土壤环境质量标准-农用地土壤风险管控标准》(GB15618-2018)(pH≤5.5)风险筛选值;Cu、Zn、Cd和As平均质量分数分别为广东省土壤背景值的2.08、2.74、6.75和1.11倍。2)重金属中Cd的潜在生态风险系数最高,潜在生态风险程度为很强,其余元素潜在生态风险程度为轻微。研究区土壤重金属的潜在生态风险程度为中等。重金属与有机质、黏土、粉砂呈正相关关系,与pH、砂呈负相关关系。3)Zn、Cr和Cu在红树植物体内质量分数较高,Pb、Ni和As次之,Cd质量分数最低。除无瓣海桑Zn的根-叶转运系数>1外,重金属在桐花树、木榄和无瓣海桑中的生物富集系数和转运系数均<1,说明桐花树、木榄和无瓣海桑对重金属的富集和转运能力不强,大部分有毒元素主要积累在根部,降低了有毒重金属通过食物链传递的风险。

关键词: 红树林, 土壤, 重金属, 生物富集系数(BCF), 转运系数(TF)

Abstract:

To explore the distribution, accumulation, and migration characteristics of mangrove soils and mangrove plants, the mass fraction of heavy metals (Cu, Zn, Pb, Cd, Cr, Ni, and As), the source thereof, and factors influencing their presence in the surface soil and different parts of mangrove plants (roots, branches, and leaves) were determined via inductively coupled plasma mass spectrometry (ICP-MS) in the Sea Promenade mangrove wetland in Xiashan District of Zhanjiang. The potential ecological risk index proposed by Hakanson was employed to evaluate the soil risk level. The influencing factors and sources of heavy metals were investigated using correlation and cluster analyses. The enrichment and migration ability of the heavy metals in soil plants were analyzed using the bioconcentration and translocation factors. The results showed that: 1) The order of concentrations (in mg·kg-1)of seven heavy metals in surface soil of the mangrove wetland was Zn (57.48) > Cr (29.31) > Pb (19.23) > Cu (16.62) > Ni (8.18) > As (6.00) > Cd (0.20). Moreover, the average mass fraction of the seven elements did not exceed the risk screening values for soil contamination regarding soil environmental quality, according to the risk control standard for soil contamination of agricultural land (GB15618-2018) (pH ≤ 5.5). The average values of Cu, Zn, Cd, and As were 2.08, 2.74, 6.75, and 1.11 times higher than the soil background values in Guangdong Province. Compared with the results of the investigation on heavy metals in 2015, the present results indicated increases in the concentrations of Cr, Cd, and Ni by 47%, 32%, and 6%, respectively; conversely, the concentrations of Cu, As, Zn, and Pb decreased by 15%, 14%, 13%, and 3%, respectively. 2) The highest potential ecological risk coefficient(Eir) values of Cd were in the range of 70-370, with an average value of 202, indicating a strong degree of potential ecological risk. The Eir values of the other elements were less than 40, indicating a slight degree of potential ecological risk. The mean value of the total potential ecological risk index (RI) of soil heavy metals investigated in the study area was 236, with a medium potential ecological risk degree. 3) The correlation analysis of heavy metals and soil physical and chemical properties showed that, except for Cd and As, there was a significant positive correlation between the heavy metal and organic matter contents, while a correlation between heavy metals and pH was negative but not statistically significant. Heavy metals were positively correlated with clay and silt but negatively correlated with sand. Organic matter, pH, and particle size are important factors that affect heavy metal accumulation in soil. 4) Concentrations of heavy metals in different mangrove plants were different. The order of heavy metal concentrations in Aegiceras corniculatum and Aegiceras corniculatum was Zn > Cr > Cu > Ni > Pb > As > Cd. The order of heavy metal concentrations in Sonneratia apetala was Zn > Cu > Cr > Ni > Pb > As > Cd. 5) The bioconcentration and translocation factors of heavy metals were less than 1 in Aegiceras corniculatum, Sonneratia apetala, and Bruguiear gymnorrhiza, indicating that the enrichment and translocation capacity of heavy metals was not high, except for the root-leaf translocation factor of Zn in Sonneratia apetala, which was greater than 1. Most of the toxic heavy metals were mainly accumulated in the roots, which reduced the risk of their delivery by the food chain.

Key words: mangrove, soil, heavy metal, Bio-Concentration Factor (BCF), Translocation Factor (TF)

中图分类号: 

  • X53