耐高盐碱蓬对湿地土壤中金属元素的富集特征研究

基于秦皇岛滨海湿地人工种植耐高盐碱蓬修复工程试验,通过分析湿地土壤沉积物及耐高盐碱蓬中不同金属元素的含量与变化,研究了耐高盐碱蓬对金属元素的富集特征。结果显示:湿地沉积物中Fe、Mn、Cr、Pb和Zn的浓度较高,分别为8 210. 94、110. 04、8. 78、8. 25、10. 95 mg/kg,Cd的浓度最低,平均值为0. 022 mg/kg,湿地试验区土壤中同一金属元素变异程度较小,分布较均匀。碱蓬体内重金属含量根据采集地点的不同有差异,但与各站位中土壤的重金属分布特征存在正相关性;其中碱蓬内Fe、Mn、Zn、Cu的平均含量相对较高,且Fe、Mn、Ni、Cu、As、Cd、Pb元素在碱蓬根中的平均含量高于茎叶,而Cr在茎中的平均含量最高,Zn和Mo在叶中的含量最高。碱蓬的根、茎、叶对Cd的富集效果最好,其次为Mo、Cu,对Fe、Mn、Zn、As和Pb的富集效果相对较差,说明碱蓬对沉积物中不同金属元素的富集移出率存在差异。金属元素在碱蓬中的转移系数研究表明,Mo、Zn、Cd和Mn等元素可由根部转移到叶中,而Fe、Ni、Pb、As和Cu等金属元素固定在根部,该研究可为利用碱蓬修复湿地重金属污染提供理论基础。

Study on Enrichment Characteristics of Metallic Elements in Wetland Soil Using Haloduric Suaeda Salsas

Based on the experiments of artificial cultivation of Suaeda salsas in coastal wetland of Qinhuangdao,the enrichment characteristics of metal elements with Suaeda salsas were studied through analyzing the contents and changes of different metal elements in wetland soil.The results showed that the contents of Fe,Mn,Cr,Pb and Zn in sediments were relatively high,with their average contents of 8 210.94,110.04,8.78,8.25,10.95 mg/kg,respectively,while the content of Cd was the lowest,with an average value of 0.022 mg/kg.The variation degree for the same metal in the sediment of the wetland was relatively small,and the distribution was more uniform.The contents of heavy metals in Suaeda salsas were different according to different sampling sites,but there was a positive correlation for them with the distribution characteristics of metals in the sediments from each station.The contents of Fe,Mn,Zn and Cu were relatively high,and the contents of Fe,Mn,Ni,Cu,As,Cd and Pb in the roots of Suaeda salsas were higher than those in stems and leaves.The content of Cr was the highest in the stems,and those of Zn,Mo were the highest in the leaves.The roots,stems and leaves of Suaeda salsas had the best enrichment effect on Cd,followed by Mo and Cu,and Suaeda salsas had a poorer enrichment ability to Fe,Mn,Zn,As and Pb,which showed that there were differences for Suaeda salsa in the enrichment and removal rates of different metal elements in the sediment.Study of translocation factors showed that Mo,Zn,Cd and Mn were transferred from the roots to the leaves,while Fe,Ni,Pb,As and Cu were immobilized at the roots of Suaeda salsas.This study could provide a theoretical basis for the remediation of heavy metal pollution in wetlands with Suaeda salsas.