利用破坏草修复矿业废弃地砷污染土壤的研究

Study on Remediation of Arsenic Contaminated Soil in Mining Wasteland by Ageratina adenophora

摘要: 为利用破坏草进行砷污染土壤的植物修复，通过实地调查和水培试验，对其As吸收能力进行实验研究，利用原子吸收光谱仪、原子荧光光谱仪、ICP-MS对破坏草根际土壤及其根、茎、叶的重金属含量进行测定，并对其重金属富集系数和转运系数进行比较分析。结果表明：1) 破坏草对多种重金属元素具有较强的耐性，并具有一定的吸收能力；2) 在野外采集的破坏草样品中，其根际土壤的砷含量高达到44209.61 mg/kg，根部的砷含量高达168.92 mg/kg，根茎叶对砷的平均富集系数为0.0127，地上部分的重金属转运系数小于1；3) 在水培试验中，破坏草根部的砷含量达到665.20 mg/kg，但转移到地上部分的砷数量较少，说明其对砷具有一定的吸收能力，吸收的砷主要累积在根部。由此可见，破坏草不是砷的超累积植物，但其生物量大，对重金属的耐性较强，适应性强，并且具有一定的砷累积能力，因此，可应用于砷污染土壤的植物修复。

Abstract: In order to used A. adenophora for phytoremediation of arsenic-contaminated soils, through field investigations and hydroponic experiments, atomic absorption spectrometer, atomic fluorescence spectrometer, ICP-MS were used to determine the content of heavy metals in A. adenophor rhizosphere soil and its roots, stems and leaves, and the heavy metal enrichment coefficients and transport coefficients were compared and analyzed. The results showed that: 1) A. adenophora has strong tolerance to multiple heavy metal elements and has a certain absorption capacity; 2) In A. adenophora samples collected in the field, the arsenic content in its rhizosphere soil is as high as 44209.61 mg/kg, the arsenic content in the roots is as high as 168.92 mg/kg. The average enrichment coefficient of arsenic in roots, stems and leaves is 0.0127, and the heavy metal transport coefficient of the aerial parts is less than 1; 3) In the hydroponic experiment, the arsenic content in the roots of the A. adenophora reached 665.20 mg/kg, but the amount of arsenic transferred to the above-ground part is small, indicating that it has a certain absorption capacity for arsenic, and the absorbed arsenic mainly accumulates in the roots. It can be seen that A. adenophora is not a super-accumulating plant of arsenic, but its biomass is large, and it has strong tolerance to heavy metals, strong adaptability, and has a certain ability to accumulate arsenic. Therefore, it can be applied to phytoremediation of arsenic-contaminated soil.