Role of assisted natural remediation in environmental cleanup
Role of assisted natural remediation in environmental cleanup
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DOI：
10.1016/j.geoderma.2004.01.003
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发表时间：
2004-10-01
期刊：
影响因子：
6.1
通讯作者：
Bolan, NS
中科院分区：
文献类型：
--
作者：
Adriano, DC;Wenzel, WW;Bolan, NS
金属是全球常见的污染物。金属在土壤中的长期沉积可导致累积、迁移和由大部分金属的移动性和生物可利用性引起的生物毒性/动物毒性。污染物的生物可利用性越来越多地被用作污染物对环境和人类健康构成的潜在风险的关键指标。然而，生物利用度的定义及其所依据的概念仍不清楚，其测量方法各不相同，因此，没有单一的标准技术来评估植物对污染物的可利用性或其对土壤生物群的生态毒理学影响。此外，生物利用度通常被认为是静态的，大多数关于风险和补救措施的决定都是基于实验室对生物利用度的估计，而生物利用度可能随着时间、物种性质以及环境因素的时间变化而变化。由于其不可改变的性质，仅仅严格的自然衰减过程可能不足以减轻金属的风险。然而，通过人为干预加速这些过程（即，协助自然补救），有效地固定金属可能是一个可行的选择。在欧洲和北美，已经在实地规模上证明了对土壤施用某些添加剂，可以增强土壤中关键的生物地球化学过程，从而有效地吸收金属。使用石灰、磷酸盐和生物固体添加剂的案例研究表明，在田间条件下，增强了自然修复，从而大大改善了植被生长，激发了微生物种群和多样性，并减少了场外金属运输。取决于土壤/水文地球化学特性，源项和金属形态/物种，和土地利用，固定效果诱导这种辅助自然补救可能是持久的。使用绿色植物作为环境清理的补救工具也提供了一些潜力。植物可以吸收和生物积累（植物提取）以及固定（植物固定）某些微量元素，与它们的根际过程。虽然某些金属络合物，如金属焦晶岩的长期稳定性已在模型系统中显示，植物根及其微生物和菌根的关联对这种稳定性的影响是未知的。一套化学和生物测试可用于监测辅助自然补救的功效。(C)2004 Elsevier B. V.保留所有权利。
Metals are common contaminants worldwide. Long-term deposition of metals in soils can lead to accumulation, transport and biotoxicity/zootoxicity caused by mobility and bioavailability of significant fraction of the metals. Contaminant bioavailability is increasingly being used as a key indicator of potential risk that contaminants pose to both environmental and human health. However, the definition of bioavailability and the concepts on which it is based are still unclear, the methods adopted for its measurement vary and as such there is no single standard technique for the assessment of either plant availability of contaminants or their ecotoxicological impacts on soil biota. Moreover, bioavailability is often assumed to be static in nature where most decisions on risk and remediation are based on laboratory estimations of the bioavailable fraction, which may vary with time, nature of species as well as with temporal variation in environmental factors. Because of their immutable nature, strict natural attenuation processes alone may not be sufficient in mitigating the risks from metals. However, accelerating these processes with human interference (i.e., assisted natural remediation) that effectively immobilizes metals might be a viable option. Application to soils of certain amendments that enhance key biogeochemical processes in soils that effectively immobilize metals have already been demonstrated in Europe and North America on a field scale. Case studies using lime, phosphate and biosolid amendments have demonstrated, under field conditions, enhanced natural remediation resulting in substantially improved vegetation growth, invigorated microbial population and diversity, and reduced offsite metal transport. Depending on soil/hydrogeochemical properties, source term and metal form/species, and land use, the immobilization efficacy induced by such assisted natural remediation may be enduring. The use of green plants as a remediation tool in environmental cleanup has also offered some potential. Plants can uptake and bioaccumulate (phytoextraction) as well as immobilize (phytoimmobilization) certain trace elements, in conjunction with their rhizospheric processes. While long-term stability of certain metal complexes, such as metal pyromorphites has been shown in model systems, the influence of plant roots and its microbial and mycorrhizal association on such stability is unknown. A suite of chemical and biological tests are available to monitor the efficacy of assisted natural remediation. (C) 2004 Elsevier B.V. All rights reserved.