Huang Xi-Hua, Wei Ze-Bin, Guo Xiao-Fang, Shi Xue-Feng, Wu Qi-Tang
Key Laboratory on Eco-Agriculture of the Ministry of Agriculture, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Huan Jing Ke Xue. 2010 Dec;31(12):3067-74.
Combining the different soil remediation technologies can overcome the shortcoming of a single technique, for example, the combination of phyto-extraction with chemical washing can enhance the phytoextraction and build up an effective technology. In a pot experiment, the co-crop of Sedum alfredii and Zea mays was conducted, chemical washing was also applied with different mixtures of chelators (MC). Metals amounts washed by leaching, the uptake of metals by plants and the metals contents remained in soils were determined. Results showed that the co-crop combining with 10 mmol x L(-1) MC washing removed the highest amount of Zn and Cd,and after 2 crops, the removal rates reached 6.0% and 40.46% of the soil total metal respectively for Zn and Cd, which were higher than those for the only co-planting. Soil analysis showed that the two successive co-crops with MC washings decreased soil Cd,Zn and Pb by 27.8% - 44.6%,12.6% -16.5% and 3.6% - 5.7%, respectively. Chemical washing with 50 mmol x L(-1) MC affected the growth of S. alfredii and resulted in higher metal contents in thereafter leachate water than the other less concentrated washing agents. EDDS ([S, S]-ethylenediaminedisuccinic acid) enhanced the phytoextraction of Cd and Zn but did not effectively wash Pb. Zn and Cd removal mainly depended on phytoextraction while Pb removal relied on MC-washing in this combined technology, by which the multi-metals contamination problem could be resolved.
结合不同的土壤修复技术可以克服单一技术的缺点，例如，植物提取与化学淋洗相结合可以增强植物提取效果，从而形成一种有效的技术。在盆栽试验中，进行了东南景天和玉米的间作，并使用不同螯合剂混合物（MC）进行化学淋洗。测定了通过淋洗去除的金属量、植物对金属的吸收量以及土壤中残留的金属含量。结果表明，间作结合10 mmol·L⁻¹ MC淋洗去除的锌和镉量最高，经过两季作物种植后，锌和镉的去除率分别达到土壤总金属量的6.0%和40.46%，高于仅间作种植的情况。土壤分析表明，连续两季作物结合MC淋洗分别使土壤中的镉、锌和铅含量降低了27.8% - 44.6%、12.6% - 16.5%和3.6% - 5.7%。50 mmol·L⁻¹ MC化学淋洗影响了东南景天的生长，且此后淋出液中的金属含量高于其他浓度较低的淋洗剂。乙二胺二琥珀酸（EDDS）增强了镉和锌的植物提取效果，但对铅的淋洗效果不佳。在这种联合技术中，锌和镉的去除主要依赖于植物提取，而铅的去除则依赖于MC淋洗，通过这种方式可以解决多金属污染问题。
