Ho Wai Mun, Ang Lai Hoe, Lee Don Koo
Forest Research Institute Malaysia, 52109 Kepong, Selangor, Malaysia.
J Environ Sci (China). 2008;20(11):1341-7. doi: 10.1016/s1001-0742(08)62231-7.
The potential of kenaf (Hibiscus cannabinus L.) for phytoremediation of lead (Pb) on sand tailings was investigated. A pot experiment employing factorial design with two main effects of fertilizer and lead was conducted in a nursery using sand tailings from an ex-tin mine as the growing medium. Results showed that Pb was found in the root, stem, and seed capsule of kenaf but not in the leaf. Application of organic fertilizer promoted greater biomass yield as well as higher accumulation capacity of Pb. In Pb-spiked treatments, roots accumulated more than 85% of total plant Pb which implies that kenaf root can be an important sink for bioavailable Pb. Scanning transmission electron microscope (STEM) X-ray microanalysis confirmed that electron-dense deposits located along cell walls of kenaf roots were Pb precipitates. The ability of kenaf to tolerate Pb and avoid phytotoxicity could be attributed to the immobilization of Pb in the roots and hence the restriction of upward movement (translocation factor < 1). With the application of fertilizer, kenaf was also found to have higher biomass and subsequently higher bioaccumulation capacity, indicating its suitability for phytoremediation of Pb-contaminated site.
研究了洋麻（Hibiscus cannabinus L.）对砂尾矿中铅（Pb）的植物修复潜力。在苗圃中进行了一项采用析因设计的盆栽试验，试验设置了肥料和铅两个主要因素，以某废弃锡矿的砂尾矿作为生长介质。结果表明，洋麻的根、茎和种荚中检测到了铅，但叶片中未检测到。施用有机肥可促进洋麻生物量的增加以及对铅的更高积累能力。在添加铅的处理中，根积累了超过85%的植物总铅，这表明洋麻的根可能是生物可利用铅的重要储存库。扫描透射电子显微镜（STEM）X射线微分析证实，洋麻根细胞壁上的电子致密沉积物为铅沉淀物。洋麻耐受铅并避免植物毒性的能力可能归因于铅在根部的固定，从而限制了其向上移动（转运系数<1）。施用肥料后，洋麻还具有更高的生物量以及更高的生物积累能力，表明其适合用于修复铅污染场地。
