以深圳市清水河垃圾焚烧厂为例,研究城市垃圾焚烧厂周围不同植物类别(乔木、灌木和草本)的重金属污染特征,探讨工作区重金属污染环境植物修复的物种选择方案及群落构建模式。采集了垃圾焚烧厂周围22个科34个物种的叶片样品,分析重金属Hg,Cr,Cd,Pb的含量和富集系数。结果表明:该垃圾焚烧厂周围优势植物在一定程度上受到了重金属的污染,不同植物类别受重金属的污染状况不同。乔木主要受Cr的污染,灌木和草本的Hg污染状况较为严重。乔-灌、乔-草之间的重金属含量及富集系数均存在差异(Pt≤0.028)。不同重金属污染植物修复可供选择的潜在物种分别是:1)Hg:乔木植物大叶相思(Acacia auriculiformis)和柠檬桉(Eucalyptus citriodora);2)Cr:草本五节芒(Miscanthus floridulus)和灌木叶子花(Bougainvillea spectabilis);3)Cd:灌木梅叶冬青(Ilex asprella)和乔木降真香(Acronychia pedunculata);4)Pb:草本酢浆草(Oxalis corniculata)和芒萁(Dicranopteris dichotoma)。构建乔-灌-草多层次的群落结构,对多种重金属复合污染区域的修复具有综合效果。
To investigate heavy metals(HMs) pollution in the different kinds of plants including trees,shrubs and herbs resulting from municipal solid waste incineration(MSWI),leaf samples in 34 species of 22 families around the Shenzhen Qingshuihe MSWI plant were collected.The levels and bioaccumulation factors of mercury(Hg),chromium(Cr),cadmium(Cd) and lead(Pb) in the leaves were determined.Results show that,these plants were polluted by HMs and the characteristics of pollution were different among trees,shrubs and herbs.Trees were mainly polluted by Cr,while shrubs and herbs by Hg.Significant differences(Pt≤ 0.028) were observed in concentrations and bioaccumulation factors between trees and shrubs,and also between trees and herbs.The potential species for different HM pollution remediation are recommended as follows:1) for Hg,the tree plants of Acacia auriculiformis and Eucalyptus citriodora;2) for Cr,the herb of Miscanthus floridulus and the shrub of Bougainvillea spectabilis;3) for Cd,the shrub of Ilex asprella and tree of Acronychia pedunculata;and 4) for Pb,the herbs of Oxalis corniculata and Dicranopteris dichotoma.Consequently,building a multi-level botanical structure consisting of trees,shrubs and herbs is helpful to phytoremediate the pollution of heavy metals.