Evaluation of Phytoremediation Potential of Castor Cultivars for Heavy Metals from Soil

ABSTRACT: Phytoremediation is a useful tool to restore heavy metals contaminated soils. This study was carried out to test two castor (Ricinus communis) cultivars [Local and DS-30] for phytoextraction of heavy metals from the soil spiked by known concentrations of seven metals (Cu, Cr, Fe, Mn, Ni, Pb and Zn). A pot experiment was laid out by using a completely randomized design. Soil and plant samples were analyzed at 100 days after planting. The data on heavy metal uptake by plant tissues (roots, leaves and shoots) of the two castor cultivars suggested that a considerable amount of metals (Fe = 27.18 mg L-1; Cu = 5.06 mg L-1; Cr = 2.95 mg L-1; Mn = 0.22 mg L-1; Ni = 4.66 mg L-1; Pb = 3.33 mg L-1; Zn = 15.04 mg L-1) was accumulated in the plant biomass. The soil heavy metal content at the end of experiment significantly decreased with both cultivars, resulting in improved soil quality. Therefore, it is concluded that both castor cultivars, Local and DS-30, can be used for phytoremediation of heavy metal-contaminated sites.

摘要：植物修复是修复重金属污染土壤的有效技术手段。本研究以两个蓖麻（Ricinus communis）品种（本地品种与DS-30）为供试材料，探究其从经已知浓度七种重金属（Cu、Cr、Fe、Mn、Ni、Pb、Zn）外源污染的土壤中提取重金属的能力。试验采用完全随机设计开展盆栽实验，于种植后100天采集土壤与植物样品并进行指标检测。对两个蓖麻品种不同植物组织（根、叶与地上部）的重金属吸收量分析结果显示，植株生物量中累积了可观的重金属（Fe=27.18 mg·L⁻¹；Cu=5.06 mg·L⁻¹；Cr=2.95 mg·L⁻¹；Mn=0.22 mg·L⁻¹；Ni=4.66 mg·L⁻¹；Pb=3.33 mg·L⁻¹；Zn=15.04 mg·L⁻¹）。试验结束后，两个品种处理组的土壤重金属含量均显著降低，土壤质量得到有效改善。综上，本地品种与DS-30这两个蓖麻品种均可应用于重金属污染场地的植物修复工作。