Departamento de Química Agrícola, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
J Environ Manage. 2011 Jun;92(6):1584-90. doi: 10.1016/j.jenvman.2011.01.022. Epub 2011 Feb 25.
Re-vegetation is the main aim of ecological restoration projects, and in Mediterranean environments native plants are desirable to achieve successful restoration. In 1998, the burst of a tailings dam flooded the Guadiamar river valley downstream from Aznalcóllar (Southern Spain) with sludges that contained elevated concentrations of metals and metalloids, polluting soils and waters. A phytoremediation experiment to assess the potential use of native shrub species for the restoration of soils affected by the spillage was performed from 2005 to 2007, with soils divided into two groups: pH < 5 and pH > 5. Four native shrubs (Myrtus communis, Retama sphaerocarpa, Rosmarinus officinalis and Tamarix gallica) were planted and left to grow without intervention. Trace element concentrations in soils and plants, their extractability in soils, transfer factors and plant survival were used to identify the most-interesting species for phytoremediation. Total As was higher in soils with pH < 5. Ammonium sulphate-extractable zinc, copper, cadmium and aluminium concentrations were higher in very-acid soils, but arsenic was extracted more efficiently when soil pH was >5. Unlike As, which was either fixed by Fe oxides or retained as sulphide, the extractable metals showed significant relationships with the corresponding total soil metal concentration and inverse relationships with soil pH. T. gallica, R. officinalis and R. sphaerocarpa survived better in soils with pH > 5, while M. communis had better survival at pH < 5. R. sphaerocarpa showed the highest survival (30%) in all soils. Trace element transfer from soil to harvestable parts was low for all species and elements, and some species may have been able to decrease trace element availability in the soil. Our results suggest that R. sphaerocarpa is an adequate plant species for phytostabilising these soils, although more research is needed to address the self-sustainability of this remediation technique and the associated environmental changes.
植被重建是生态恢复项目的主要目标，在 地中海环境中，为了实现成功的恢复，理想情况下会选择使用本地植物。1998 年，尾矿坝决堤，大量泥浆涌入西班牙南部阿纳克里尔（Aznalcóllar）下游的瓜迪亚马河河谷，这些泥浆中含有高浓度的金属和类金属，污染了土壤和水。为了评估利用本地灌木物种修复受溢油影响土壤的潜力，2005 年至 2007 年进行了一项植物修复实验，将土壤分为两组：pH 值<5 和 pH 值>5。种植了四种本地灌木（桃金娘、滨藜、迷迭香和柽柳），然后让它们自由生长，不进行任何干预。使用土壤和植物中的微量元素浓度、土壤中的可提取性、转移因子和植物存活率来确定最适合植物修复的物种。pH 值<5 的土壤中总砷含量较高。在强酸性土壤中，硫酸铵可提取的锌、铜、镉和铝浓度较高，但当土壤 pH 值>5 时，砷的提取效率更高。与被铁氧化物固定或作为硫化物保留的砷不同，可提取的金属与相应的土壤全金属浓度呈显著关系，与土壤 pH 值呈反比关系。T. gallica、R. officinalis 和 R. sphaerocarpa 在 pH 值>5 的土壤中生存状况更好，而 M. communis 在 pH 值<5 的土壤中生存状况更好。R. sphaerocarpa 在所有土壤中的存活率最高（30%）。所有物种和元素从土壤向可收获部分的微量元素转移都很低，一些物种可能能够降低土壤中微量元素的有效性。我们的研究结果表明，R. sphaerocarpa 是一种适合用于稳定这些土壤的植物物种，尽管需要进一步的研究来解决这种修复技术的自我可持续性以及相关的环境变化。
