热带地理 ›› 2019, Vol. 39 ›› Issue (3): 347-356.doi: 10.13284/j.cnki.rddl.003132

• 论文 • 上一篇    下一篇

徐闻南山镇红树林沉积物及红树植物中重金属的累积特征与迁移规律

罗松英,梁艺琼,陈碧珊,林梦婷,梁家新,邱锦坤   

  1. (岭南师范学院 地理系,广东 湛江 524048)
  • 收稿日期:2018-12-13 修回日期:2019-04-18 出版日期:2019-05-05 发布日期:2019-05-05
  • 作者简介:罗松英(1985—),女,广东阳春市人,博士,讲师,主要从事土壤重金属污染、环境地球化学等研究,(E-mail)luosongying@163.com。
  • 基金资助:

    国家自然科学基金项目(41606053);广东省教育厅青年创新人才项目(2018KQNCX152);岭南师范学院人才引进专项项目(ZL1607)

Accumulation and Migration of Heavy Metals in Mangrove Sediments and Plants in the Nanshan Town, Xuwen

Luo Songying, Liang Yiqiong, Chen Bishan, Lin Mengting, Liang Jiaxin and Qiu Jinkun   

  1. ( Department of Geography, Lingnan Normal University, Zhanjiang 524048, China )
  • Received:2018-12-13 Revised:2019-04-18 Online:2019-05-05 Published:2019-05-05

摘要:

为探究重金属在红树林沉积物及红树植物中的分布累积及迁移规律,选取了徐闻南山镇红树林为研究对象,通过测定红树林沉积物及红树植物不同部位(根、茎、叶)的重金属质量分数,运用富集因子、生物富集系数、转移系数及相关性分析等方法进行分析。结果表明:1)红树林沉积物重金属质量分数表现为铬(Cr)>锌(Zn)>镍(Ni)>铜(Cu)>铅(Pb)>砷(As)>汞(Hg)>镉(Cd),为中等变异程度;除了镍(Ni)元素外,其余7种重金属未超过国家一级标准,除了铅(Pb)元素外,其余7种重金属均超过广东省土壤环境背景值,说明研究区沉积物中重金属具有一定的积累效应。2)沉积物中砷(As)、铜(Cu)、锌(Zn)、汞(Hg)、镍(Ni)、铬(Cr)富集因子值均>1.5,说明受到轻微人为活动影响;各站位镍(Ni)富集因子值均>5,结合研究区背景,反映了镍(Ni)受到自然和人为输入的共同影响。3)白骨壤体内重金属主要集中在根部,而红海榄体内重金属在根茎叶中分布相对均匀。白骨壤根茎叶部位的大多数重金属质量分数远高于红海榄,说明白骨壤对重金属的吸附能力比红海榄强。汞(Hg)集中分布在植物的叶片部位,且与其他重金属之间相关性不明显;推测汞(Hg)主要通过叶片吸收进入植物体内,与交通运输污染有关。4)不同红树植物对不同重金属富集能力各异,白骨壤对重金属的富集能力表现为:镉(Cd)>砷(As)>铜(Cu)>锌(Zn)>汞(Hg)>铅(Pb)>镍(Ni)>铬(Cr),红海榄表现为:镉(Cd)>铜(Cu)>汞(Hg)>锌(Zn)>铅(Pb)>砷(As)>镍(Ni)>铬(Cr)。白骨壤和红海榄对汞(Hg)的运移能力都较强;红海榄对镉(Cd)的富集能力和转运能力都较强,而白骨壤对镉(Cd)富集能力较强,转运能力却较弱,这说明红树植物对重金属元素的富集能力与转运能力不存在正比关系。

关键词: 沉积物, 富集, 转移系数, 重金属, 红树植物, 徐闻南山镇

Abstract:

In the present study, we investigated the distribution, accumulation, and migration of heavy metals in mangrove sediments and plants in Nanshan Town of Xuwen County. The mangrove sediments and different parts of mangrove plants (roots, stems, and leaves) were collected, and their heavy metal contents were determined and analyzed using enrichment factors, bioaccumulation factors, transfer coefficients, and correlation analysis. The results showed that: 1) The heavy metal content in the sediments of mangrove wetland exhibited the order Cr>Zn>Ni>Cu>Pb>As>Hg>Cd, with a moderate degree of variation. Except Ni, the other seven heavy metals did not exceed the national first-class standard, and except Pb, the other seven heavy metals exceeded the background value of soil environment in Guangdong Province, indicating the existence of a certain accumulation effect in the process of heavy metal deposition in the study area. 2) The Enrichment Factors of As, Cu, Zn, Hg, Ni, and Cr in the sediments were greater than 1.5, indicating a potential effect of slight human activities. The Enrichment Factors of Ni were greater than 5 at each station. Combined with the background of the study area, it reflected that the Ni content was affected by both natural and human inputs. 3) The heavy metals were mainly concentrated in the roots of Avicennia marina, but were relatively uniform in the roots, stem, and leaves of Rhizophora sty losa. The contents of heavy metals in different parts of A. marina were much higher than those in the corresponding parts of R. sty losa, indicating that the heavy metal adsorption capacity of A. marina was stronger than R. sty losa. Hg was concentrated in the leaves of plants, and the correlation between Hg and other heavy metals was not obvious, indicating that they had different sources. It was speculated that Hg mainly enters the plants through leaves, mostly from transportation pollution through atmospheric deposition. 4) Different mangrove plants exhibit different enrichment abilities for different heavy metals. The enrichment ability for different heavy metals followed the order Cd>As>Cu>Zn>Hg>Pb>Ni>Cr in A. marina and Cd>Cu>Hg>Zn>Pb>As>Ni>Cr in R. sty losa. Both A. marina and R. sty losa had strong transport capacities for Hg. Rhizophora sty losa has a strong ability to enrich and transport Cd, whereas A. marina has a strong ability to enrich Cd, but a weak ability to transport Cd, indicating that there is no direct relationship between the accumulation and transport capacity of heavy metals in mangrove plants.

Key words: sediment, enrichment, Transfer Coefficient, heavy metals, mangrove plants, Nanshan Town of Xuwen County