Pedron F, Petruzzelli G, Barbafieri M, Tassi E
National Research Council, Institute of Ecosystem Study, Pisa, Via Moruzzi 1, 56124 Pisa, Italy.
Chemosphere. 2009 May;75(6):808-14. doi: 10.1016/j.chemosphere.2009.01.044. Epub 2009 Feb 12.
In microcosm experiments, the use of inorganic and organic amendments has been studied as potential agents to reduce heavy metal bioavailability in an acidic soil highly contaminated by Cu, Zn and Ni, that has to be remediated by phytoremediation. The concentrations of heavy metals in the original soil (O-Soil) produced phytotoxic effects with a strong reduction in biomass yield that hinder the utilization of this technology. To overcome phytotoxicity the use of three immobilizing agents was evaluated. The results obtained showed that all the strategies decreased the mobile fractions of heavy metals in soil and increased the metal removal efficiency. In the case of Brassica juncea the best results for Zn and Ni were obtained after zeolites addition (Z-Soil) with an increase of about 6 times with respect to the value found in the O-Soil. In the case of Cu, the more efficient treatment was Ca(OH)(2) addition (Ca-Soil). The B. juncea plants accumulated Cu amounts 8 times greater than in the O-Soil. For this metal, relevant results were obtained also with compost, that increased the amount of Cu in the plants of 7 times with respect to the O-Soil. Similar results were obtained with Helianthus annuus the highest Zn and Ni accumulation was detected in the Z-Soil and compost-treated soils (C-Soil), with an increase of nearly 11 times with respect to the accumulation in the O-Soil. In the case of Cu the highest increase of total uptake was found in the C-Soil: 28 times higher than in the O-Soil. Total accumulation in Poa annua plants showed the highest removal efficiency in the Z-Soil for all metals. The values obtained increased of 4, 11 and 12 times for Cu, Zn and Ni, respectively.
在微观实验中，研究了使用无机和有机改良剂作为潜在试剂，以降低铜、锌和镍高度污染的酸性土壤中重金属的生物有效性，该土壤必须通过植物修复进行治理。原始土壤（O-土壤）中的重金属浓度产生了植物毒性效应，生物量产量大幅降低，这阻碍了该技术的应用。为了克服植物毒性，评估了三种固定剂的使用。获得的结果表明，所有策略都降低了土壤中重金属的可移动部分，并提高了金属去除效率。对于芥菜，添加沸石（Z-土壤）后，锌和镍的效果最佳，相对于O-土壤中的值增加了约6倍。对于铜，更有效的处理方法是添加Ca(OH)₂（Ca-土壤）。芥菜植物积累的铜量比O-土壤中高8倍。对于这种金属，堆肥也取得了相关结果，使植物中的铜含量相对于O-土壤增加了7倍。向日葵也获得了类似的结果，在Z-土壤和堆肥处理的土壤（C-土壤）中检测到最高的锌和镍积累量，相对于O-土壤中的积累量增加了近11倍。对于铜，总吸收量的最高增加量出现在C-土壤中：比O-土壤中高28倍。早熟禾植物的总积累量在Z-土壤中对所有金属都显示出最高的去除效率。获得的值分别使铜、锌和镍增加了4倍、11倍和12倍。
