红托竹荪与覆土土壤重金属污染评价及迁移能力分析

Content and Migration of Heavy Metals in Dictyophora rubrovalvata and Soil

【目的】探讨红托竹荪与覆土土壤重金属元素含量之间的关系,以期为改善竹荪品质提供理论参考。【方法】对红托竹荪中菌柄+菌裙、菌托、菌盖、覆土土壤中的5种重金属(Cd、Pb、Hg、As、Cr)进行含量测定,同时对红托竹荪及其覆土土壤重金属进行污染评价,分析红托竹荪中不同部位对这5种重金属的富集特性及各元素的相关性。【结果】红托竹荪中重金属元素含量由高到低依次为Cd>Cr>As>Pb>Hg,变异系数变化范围为15.38%~65.66%,相对应的覆土土壤中重金属元素含量高低顺序为Cr>Pb>As>Cd>Hg。覆土土壤中5种重金属元素中仅Cd元素含量超标,其余4种元素均未超标。红托竹荪3个部位对元素Cd的富集系数均大于1.5,对元素As的富集系数均小于0.5,对元素Pb、Hg和Cr富集系数小于0.1。对红托竹荪中重金属元素进行的Pearson相关性统计显示,Pb与Cr在0.01水平(双侧)上显著相关,呈完全正相关关系,其他重金属元素之间的相关性都不明显,均未达到显著水平。对红托竹荪各重金属元素与覆土土壤重金属元素之间的相关性进行统计分析,结果显示除元素Hg呈正相关之外,其余4种元素均为负相关关系。【结论】红托竹荪中以单因子污染指数分析,红托竹荪的3个部位均受到Cd重度污染,Hg含量属于清洁水平,Pb和As尚属清洁。以内梅罗综合污染指数分析,竹荪全部受到污染,且污染相当严重。红托竹荪对不同重金属元素的富集能力有明显差异,除Cd元素相对富集之外,其他的4种元素都相对贫化。由Pearson相关性分析可知Pb与Cr存在协同效应,其他重金属元素之间相关性不明显。

【Objective】Relationship between heavy metal contents in Dictyophora rubrovalvata and the soil the mushrooms were cultivated on was analyzed to understand the migratory pattern and pollution control.【Method】Contents of Cd,Pb,Hg,As,and Cr in stipe+skirt,receptacle,and cap of D.rubrovalvata as well as the overlying soil on the cultivation bed were analyzed to decipher the correlation between them.【Result】Contents of the heavy metals in D.rubrovalvata ranked Cd>Cr>As>Pb>Hg with a coefficient of variation ranging from 15.38%to 65.66%,while that in the soil Cr>Pb>As>Cd>Hg.Among the 5 heavy metals,only Cd in soil exceeded the safety standard.The enrichment coefficients of Cd in the 3 parts of D.rubrovalvata surpassed 1.5,while that of As less than 0.5 and those of Pb,Hg,and Cr below 0.1.A significant Pearson correlation was found between Pb and Cr at P<0.01(bilateral),but not among other heavy metals.The correlation between heavy metal elements in D.rubrovalvata and heavy metal elements in soil was statistically analyzed,the results showed that the other four elements had negative correlation except Hg.【Conclusion】The tested D.rubrovalvata was heavily contaminated with Cd,clean on Hg,and relatively clean on Pb or As.The Nemerow indexing put all parts of the D.rubrovalvata seriously contaminated by heavy metals.There were significant differences in the enrichment ability of different heavy metal elements.Except for the relative enrichment of Cd,the other four elements were relatively depleted.According to Pearson correlation analysis,there is a synergistic effect between Pb and Cr,and the correlation between other heavy metals is not obvious.