多年生黑麦草对黄壤重金属污染的修复

Repairation of Lolium perenne on Yellow Soil Heavy Metal Pollution

为重金属污染土壤的修复提供依据,采用定位观测试验,研究黄壤种植多年生黑麦草6年间土壤和植株重金属As、Hg、Pb、Cr、Cd含量的变化。结果表明:1)多年生黑麦草从根部向地上部运输重金属的能力顺序为Cd>Cr>As>Pb>Hg,地上部对重金属的富集能力顺序为Cd>Cr>Pb>As>Hg,对Cr、Pb、As、Hg的富集能力弱,对Cd为中等富集能力;根系对重金属的富集能力顺序为Pb>Cd>Cr>Hg>As,对As富集能力弱,对Pb、Cd、Cr、Hg为中等富集能力。根系对重金属的富集能力总体比地上部强。2)经过6年种植黑麦草,土壤中As、Pb、Cr、Cd含量分别比种植初期降低了52.71%、45.12%、48.32%、59.15%,单项污染指数分别由种植前的2.67、0.31、1.92和3.48降低为1.26、0.17、0.99和1.42,重金属污染得到不同程度的修复。

To provide a reference for repairing heavy metal contaminated soil,the positioning observation experiment method was adopted to study the content variation of As,Hg,Pb,Cr and Cd in soil and L.perenne plants.Results：1）the transportation capability from root to the aboveground of L.perennefollowed the sequence of Cd〉Cr〉As〉Pb〉Hg,the stem-root ratio of Cd was the highest with an average of 1;Enrichment capacity of aboveground parts was Cd〉Cr〉Pb〉As〉Hg,which was weak to Cr,Pb,As and Hg,medium to Cd;Root system enrichment capacity was Pb〉Cd〉Cr〉Hg〉As,which was weak to As and medium to Pb,Cd,Cr and Hg.The root system was of stronger enrichment capacity than the aboveground part in general.2）After six years of planting L.perenne,the contents of As,Pb,Cr and Cd decreased by 52.71%,45.12%,48.32% and 59.15% respectively.And the single contamination index decreased from 2.67,0.31,1.92 and 3.48 to 1.26,0.17,0.19 and 1.42 separately.The heavy metal pollution was repaired in varymg degrees.