Abstract

Phytoextraction potential of a co-planting system was evaluated using a shrub and an herbaceous species and compared with monocultures. A greenhouse experiment with Salix interior and Trifolium pratense grown in combination or alone was conducted for 120 days in soil either uncontaminated or contaminated with wood preservatives containing mixed chromated copper arsenate and pentachlorophenol (PCP). The results showed that the plant species produced similar amounts of dry biomass per pot in monoculture and co-planting, whether growing in contaminated or uncontaminated soil. Arsenic (As), chromium (Cr) and copper (Cu) concentrations in root tissue of S. interior increased 8.6%, 65.9% and 4.5%, respectively, in co-planting compared to its monoculture. T. pratense had superior concentration of As (14% higher) in root tissue when co-planted. However, the higher trace elements concentrations in the plant tissues did not translate into measurable differences in total trace element removal per pot, except for As. The bioconcentration factor for Cu and As was high in the belowground portions of the plants in co-planting. PCP levels in the soil decreased to values near the limit of detection in all treatments. These results suggest that co-planting S. interior with T. pratense could lead to higher phytoextraction potential than monoculture.

摘要

使用灌木和草本物种评估了共栽系统的植物提取潜力，并与单一栽培进行了比较。在没有污染或被含有混合铬酸铜和五氯酚（PCP）的木材防腐剂污染的土壤中，进行了柳柳和内生三叶草的组合或单独生长的温室试验，为期120天。结果表明，无论是在受污染的土壤还是未受污染的土壤中生长，这种植物物种在单一栽培和联合种植中每个盆栽产生的干生物量相似。与单一种植相比，共栽的室内链球菌根组织中的砷（As），铬（Cr）和铜（Cu）浓度分别增加了8.6％，65.9％和4.5％。红三叶如（14％以上）在根组织中的具有优异的浓度时助播种。但是，除砷外，植物组织中较高的微量元素浓度并未转化为每个盆中总微量元素去除量的可测量差异。在共同种植的植物的地下部分，Cu和As的生物浓缩系数很高。在所有处理中，土壤中的PCP含量均降至接近检测极限的值。这些结果表明，与T. pratense一起种植S. Interior可能比单作导致更高的植物提取潜力。