Suman Jachym, Uhlik Ondrej, Viktorova Jitka, Macek Tomas
Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Czechia.
Front Plant Sci. 2018 Oct 16;9:1476. doi: 10.3389/fpls.2018.01476. eCollection 2018.
Pollution by heavy metals (HM) represents a serious threat for both the environment and human health. Due to their elemental character, HM cannot be chemically degraded, and their detoxification in the environment mostly resides either in stabilization or in their removal from the matrix, e.g., soil. For this purpose, phytoremediation, i.e., the application of plants for the restoration of a polluted environment, has been proposed as a promising green alternative to traditional physical and chemical methods. Among the phytoremediation techniques, phytoextraction refers to the removal of HM from the matrix through their uptake by a plant. It possesses considerable advantages over traditional techniques, especially due to its cost effectiveness, potential treatment of multiple HM simultaneously, no need for the excavation of contaminated soil, good acceptance by the public, the possibility of follow-up processing of the biomass produced, etc. In this review, we focused on three basic HM phytoextraction strategies that differ in the type of plant species being employed: natural hyperaccumulators, fast-growing plant species with high-biomass production and, potentially, plants genetically engineered toward a phenotype that favors efficient HM uptake and boosted HM tolerance. Considerable knowledge on the applicability of plants for HM phytoextraction has been gathered to date from both lab-scale studies performed under controlled model conditions and field trials using real environmental conditions. Based on this knowledge, many specific applications of plants for the remediation of HM-polluted soils have been proposed. Such studies often also include suggestions for the further processing of HM-contaminated biomass, therefore providing an added economical value. Based on the examples presented here, we recommend that intensive research be performed on the selection of appropriate plant taxa for various sets of conditions, environmental risk assessment, the fate of HM-enriched biomass, economical aspects of the process, etc.
重金属污染对环境和人类健康都构成了严重威胁。由于其元素特性，重金属无法通过化学方法降解，其在环境中的解毒主要在于稳定化或从基质（如土壤）中去除。为此，植物修复，即利用植物恢复受污染环境，已被提议作为一种有前景的绿色替代传统物理和化学方法。在植物修复技术中，植物提取是指通过植物吸收从基质中去除重金属。它相对于传统技术具有相当大的优势，特别是因其成本效益、能同时处理多种重金属、无需挖掘受污染土壤、公众接受度高、所产生生物量后续可加工等。在本综述中，我们重点关注了三种基本的重金属植物提取策略，它们在所使用的植物物种类型上有所不同：天然超富集植物、具有高生物量产量的快速生长植物物种，以及可能经过基因工程改造以具有有利于高效吸收重金属和增强重金属耐受性表型的植物。迄今为止，从在受控模型条件下进行的实验室规模研究以及使用实际环境条件的田间试验中，已经积累了关于植物用于重金属植物提取适用性的大量知识。基于这些知识，已经提出了许多植物用于修复重金属污染土壤的具体应用。此类研究通常还包括对重金属污染生物量进一步加工的建议，因此提供了额外的经济价值。基于此处给出的示例，我们建议针对各种条件下合适植物类群的选择、环境风险评估、重金属富集生物量的去向、该过程的经济方面等进行深入研究。
