5种矿区土著植物对铅污染土壤的修复潜力研究

为评估我国西北某矿区茵陈蒿、蒲公英、苜蓿、大叶苦菜和车前草5种土著作物对含铅（Pb）土壤的修复潜力，采用盆栽实验，设置4种不同Pb含量水平（0、2‰、3‰和5‰，质量分数），测定作物不同组织器官中和种植前后土壤中Pb含量，以及根际与非根际土壤微生物生物量碳含量、过氧化氢酶活性等指标。结果表明:茵陈蒿和车前草适合种植于铅含量为2‰、3‰、5‰的土壤中，可去除12%~32%的土壤Pb，车前草根系和茵陈蒿茎叶对Pb的累积量最高分别达到3617，720 mg/kg，显著高于其他植物，作为土壤铅污染修复植物的潜力较大。根际土壤微生物生物量碳含量比非根际土壤微生物生物量碳含量高2.37%~13.89%。土壤Pb抑制了根际与非根际土壤过氧化氢酶活性，使其活性低于对照组0.44%~22.3%，根际土壤过氧化氢酶活性比非根际过氧化氢酶活性高0.89%~8.09%。研究结果可为Pb污染矿区废弃地植物修复和土壤环境质量评价提供理论依据。

PHYTOREMEDIATION POTENTIAL OF FIVE NATIVE PLANTS IN SOILS CONTAMINATED WITH LEAD IN A MINING AREA

Metal pollution in soils is an issue of global concern, and lead (Pb) pollution is considered to be the most serious type. In this study, five native cropswormwood (Artemisia capillaris), dandelion (Taraxacum mongolicum), alfalfa (Medicago sativa), sauce (Lxeris chinensis), and plantain (Plantago asiatica L.)] that grow naturally around the tailings slag in a mining area in Northwest China were selected to test their ecological restoration impacts on Pb-contaminated soil. In pot experiments, different metal lead pollution gradients (0, 2‰, 3‰, and 5‰, w/w) were set, the changes of soil Pb content in different tissues and organs before and after planting were analyzed. The results showed that wormwood and plantain were suitable for planting under various soil Pb pollution levels, and the removal rate was 12%~32%. The accumulation of Pb in the roots of plantain and the stems of dandelion was more advantageous than in other plants, up to 3617,720 mg/kg respectively. These two crops had great potential as remediation plants for soil Pb pollution. The content of microbial biomass carbon in rhizosphere soil was 2.37%~13.89% higher than that in bulk soil. The catalase activity of rhizosphere and bulk soil was inhibited by soil Pb, which was 0.44%~22.3% lower than that of the control, and the catalase activity of rhizosphere soil was 0.89%~8.09% higher than that of bulk soil. The results can provide a theoretical basis for phytoremediation and soil environmental quality evaluation of Pb contaminated wasteland in mining areas.