低放核素污染土-水介质的植物修复研究进展

植物修复技术是利用植物根系吸收水分和养分的过程来吸收和转化土壤和水体中的污染物,以期达到清除,修复和治理的目的,是用于对土壤-水体中重金属和放射性核素污染清除的生态技术.本文就放射性核素的来源、污染现状、植物对放射性核素的积累筛选以及对污染土壤的修复研究进行综述,以明确植物修复技术在改善环境中的作用,为进一步筛选超积累植物并探讨植物对放射性核素污染的修复机理提供参考.     

植物超积累重金属的生理机制研究进展

土壤重金属污染已经成为一个全球性问题。重金属超积累植物在修复土壤重金属污染中具有重要的应用前景。重金属超积累植物通常具备三个基本特征,即：根系具有从土壤中吸收重金属的强大能力、能从根到地上部分高效转运重金属、在叶片中能解毒和隔离大量重金属。本文总结了重金属超积累植物吸收、转运、隔离和解毒重金属的生理机制研究进展,以期为进一步阐明植物超积累重金属的机制及其在植物修复中的应用提供参考。     

重金属污染土壤的植物修复技术

土壤受重金属污染的状况在国内外都相当严重,传统的重金属污染土壤的修复技术存在许多难以克服的缺陷;近年来,一种运用植物来去除有毒重金属的新兴修复技术(植物修复技术)给这一问题提供了良好的解决途径,该技术被认为是一种低成本有效的“绿色”技术。但其主要缺点是修复周期较长,筛选、培育超积累植物以及提高土壤中重金属的生物有效性是提高植物吸收效果、缩短修复周期的关键。本文就超积累植物的筛选、转基因超积累植物及螯合剂强化植物吸收等热点问题的研究进展作了介绍,并对我国当前植物修复技术研究工作的重点提出了建议。     

汞污染土壤植物修复技术研究进展

汞是一种全球性污染物,汞污染土壤的修复问题,一直倍受各国科学工作者关注,土壤汞污染的植物修复技术是近年来发展起来的新兴技术.其中,汞污染土壤的植物提取技术是最有发展前途的一种汞污染土壤植物修复技术.本文对国内外有关汞污染土壤的植物修复技术进行了系统分析,对有关汞污染土壤的植物修复应用技术,如植物挥发、固化及提取等修复方法进行了评述,探讨了植物修复技术在汞污染土壤修复中的应用前景.加快对汞超积累植物的筛选和植物体对重金属耐性机制的研究,对今后开展汞污染土壤的植物修复工作具有重要的现实意义.     

铬渣堆放场地土壤的污染过程、影响因素及植物修复

铬渣堆放场地的土壤污染已成为重要的环境问题之一,并引起广泛关注。为了对铬渣堆场铬污染情况有更加详细的了解,本文对铬渣污染土壤的2个基本过程(铬渣中铬的水平迁移过程与垂直运移过程)、土壤有机质、pH、Eh和含水量、土壤类型及其无机胶体组成以及地下水运动方向等影响其迁移的因素进行了分析。在此基础上,对铬超积累植物的筛选、铬超积累植物的富集机制、铬渣堆场周围污染土壤的植物修复及其机理进行了概述。虽然目前对铬污染土壤的植物修复还处于起步阶段,但利用超积累植物对铬渣污染场地进行修复前景广阔。     

我国土壤重金属污染植物吸取修复研究进展

我国从上世纪90年代中后期开始土壤重金属（含类金属砷）污染的植物吸取修复研究及技术探索,先后发现了一批具有较高研究价值和应用前景的铜、砷、镉、锰等重金属的积累或超积累植物,并从重金属耐性和超积累生理机制、植物吸取修复的根际过程与机制、吸取修复强化措施和修复植物处置与资源化利用等方面进行了研究,同时开展了植物吸取修复技术的示范与应用,已有一些较成功的植物修复工程应用案例,使我国重金属污染土壤植物修复技术,尤其是植物吸取修复技术在国际上产生了较强的影响力。本文就近年来我国土壤重金属污染植物吸取修复研究进展进行了综述,并对今后的发展趋势进行了展望。     

重金属污染土壤植物修复基本原理及强化措施探讨

阐述了植物修复的基本概念及主要作用方式 ,并从土壤中重金属存在形态 ,植物对重金属吸收、排泄和积累以及植物生物学特性与植物修复的关系等方面讨论了重金属污染土壤植物修复的基本原理及局限性和限制性因素 ,从超富集植物性能强化和技术强化两方面探讨了植物修复的强化措施 ,并指出与现代化农业技术相结合是植物修复重金属污染土壤大规模商业应用的一条捷径     

植物修复——治理土壤重金属污染的新途径

介绍了重金属污染土壤的植物修复的概念、原理与研究动态以及重金属超积累植物的特性 ,及其在治理污染土壤中的潜力 ,为土壤重金属污染的整治及其生态的修复提出新途径。     

铜矿区超积累Cu植物的研究

1　引　　言土壤重金属污染一直是环境污染问题之一 ,而且土壤中的重金属污染具有严重性、长期性和广泛性的特点[1 ,6] .但常规的一些物理化学方法因费用过高、对土壤性质破坏等一系列问题而难以广泛应用 ,植物修复为重金属污染带来了希望[5,7,9,1 3] .植物修复主要是基于重金属超积累植物 (ｈｙｐｅｒ ａｃｃｕｍｕｌａｔｏｒ)的研究而兴起的 .超积累植物是指地上部分能富集重金属占干重的 1 0 0ｍｇ·ｋｇ-1 (Ｃｕ、Ｐｂ、Ｃｄ)或 1 0 0 0 0ｍｇ·ｋｇ-1 (如Ｚｎ)的一类植物[2～ 4,8] .在过去 2 0年内 ,已报道的超积累植物已有 4 0 0余种 …     

镉超积累植物及植物镉积累特性转基因改良研究进展

植物提取修复技术是一项既经济又环保的土壤镉(Cd)污染修复技术,该技术的关键是筛选Cd超积累植物或利用基因工程手段改良植物以提高其Cd积累能力。人们已发现遏兰菜等7种Cd超积累植物及美人蕉等潜在的Cd超积累植物。还发现了许多与Cd耐受和积累能力有关的基因:(1)编码与Cd积累、耐受有关酶的基因,如细菌中的ACC(1-aminocyclopropane-1-carboxylic acid),植物中的PCS(Phytochelatin Synthase)基因;(2)编码金属结合蛋白的基因:MT(Metallothionein)、转运蛋白(P-type ATPase、ABC型转运器)基因;(3)其它相关基因:Hvhsp17、PvSR2(Phaseolus vulgaris stress-related gene number 2)等。并将其中的一些基因转入到其它生物中,提高了其对Cd的耐受性和积累量,为实现Cd污染土壤修复的目标奠定基础。     

根际圈在污染土壤修复中的作用与机理分析

根际圈以植物根系为中心聚集了大量的生命物质及其分泌物,构成了极为独特的“生态修复单元”。本文叙述了根在根际圈污染土壤修复中的生理生态作用,富集、固定重金属,吸收、降解有机污染物等功能;菌根真菌对根际圈内重金属的吸收、屏障及螯合作用,对有机污染物的降解作用;根际圈内细菌对重金属的吸附与固定,对有机污染物的降解作用以及根际圈真菌和细菌的联合修复作用等,同时对可能存在的机理进行了分析,认为根际圈对污染土壤的修复作用是植物修复的重要组成部分和主要理论基础之一,并指出利用重金属超富集植物修复重金属污染土壤具有广阔的应用前景;筛选对水溶性有机污染物高吸收富集及其根 发泌能力强的特异植物,同时接种利于有机污染物降解的专性或非专性真菌和细菌可能会成为有机污染土壤植物修复研究的重要方向之一。     

Tolerance of Ornamental Succulent Plant Crown of Thorns (Euphorbia milli) to Chromium and its Remediation

The potential of an ornamental shrub Crown of thorns (Euphorbia milli) was evaluated for remediation of soil contaminated with Cr. The plant is one of the rare succulent ornamental shrubs with a slow to moderate growth rate and is capable of blooming almost year-round. The plant could tolerate well up to 75 mg of applied Cr and beyond that there was mortality of plants. Though the plant could not be classified as a hyperaccumulator, the plant was still very efficient in translocating Cr from roots to shoots as evident from the data on uptake and translocation efficiency values. The translocation efficiency of over 80% in our study demonstrates that a large proportion of Cr has been translocated to the harvestable biomass of the plant and therefore, this plant could be effectively recommended for the remediation of soils contaminated with low to medium level of contamination i.e., up to 50 mg/kg soil.     

解磷微生物修复土壤重金属污染研究进展

土壤重金属污染问题日益严重,具有普遍性、隐蔽性、表聚性、不可逆性等特点,已经成为环境污染治理中的热点、难点问题。解磷微生物能够依靠自身的代谢产物或通过与其他生物的协同作用,将土壤中的难溶性磷转化为可供植物吸收利用的磷,具有多重植物促生长功能和重金属解毒能力,可在重金属毒害水平下,促进植物生长、提高植物抗病能力、克服重金属对植物生长的不利影响,从而增强重金属修复植物的生存竞争力。从解磷微生物的研究现状入手,介绍了解磷微生物对土壤重金属污染的修复能力,综述了解磷微生物对土壤重金属污染修复的作用机制,分析了目前解磷微生物在重金属修复过程中存在的问题,并提出了今后研究的方向,为重金属污染土壤的修复提供了新思路。     

高生物量经济植物修复重金属污染土壤研究进展

植物修复是重金属污染土壤修复的重要方法之一。利用高生物量经济植物修复重金属污染土壤,能够兼顾生态和经济效益,具有很大的应用前景。本文系统分析了植物修复现状及存在的问题,提出利用高生物量经济植物修复重金属污染土壤的优势,总结了近年来利用高生物量经济植物吸收重金属的研究进展,探讨了改善高生物量经济植物修复重金属污染土壤效率的方法,以期为提高植物修复经济效益、促进植物修复广泛应用提供参考。     

Using hyperaccumulator plants to phytoextract soil Ni and Cd

Two strategies of phytoextraction have been shown to have promise for practical soil remediation: domestication of natural hyperaccumulators and bioengineering plants with the genes that allow natural hyperaccumulators to achieve useful phytoextraction. Because different elements have different value, some can be phytomined for profit and others can be phytoremediated at lower cost than soil removal and replacement. Ni phytoextraction from contaminated or mineralized soils offers economic return greater than producing most crops, especially when considering the low fertility or phytotoxicity of Ni rich soils. Only soils that require remediation based on risk assessment will comprise the market for phytoremediation. Improved risk assessment has indicated that most Zn + Cd contaminated soils will not require Cd phytoextraction because the Zn limits practical risk from soil Cd. But rice and tobacco, and foods grown on soils with Cd contamination without corresponding 100-fold greater Zn contamination, allow Cd to readily enter food plants and diets. Clear evidence of human renal tubular dysfunction from soil Cd has only been obtained for subsistence rice farm families in Asia. Because of historic metal mining and smelting, Zn + Cd contaminated rice soils have been found in Japan, China, Korea, Vietnam and Thailand. Phytoextraction using southern France populations of Thlaspi caerulescens appears to be the only practical method to alleviate Cd risk without soil removal and replacement. The southern France plants accumulate 10-20-fold higher Cd in shoots than most T. caerulescens populations such as those from Belgium and the UK. Addition of fertilizers to maximize yield does not reduce Cd concentration in shoots; and soil management promotes annual Cd removal. The value of Cd in the plants is low, so the remediation service must pay the costs of Cd phytoextraction plus profits to the parties who conduct phytoextraction. Some other plants have been studied for Cd phytoextraction, but annual removals are much lower than the best T. caerulescens. Improved cultivars with higher yields and retaining this remarkable Cd phytoextraction potential are being bred using normal plant breeding techniques.     

Estimation of heavy metal resistance in the second generation of creeping bentgrass (<Emphasis Type="Italic">Agrostis solonifera</Emphasis>) obtained by cell selection for resistance to these contaminants and the ability of this plant to accumulate heavy metals

Creeping bentgrass plants have been grown from seeds obtained from plants subjected to cell selection for resistance to heavy metals and NaCl, and the sensitivity of the plants and seeds to cadmium, copper, zinc and lead in the soil has been assessed. The data obtained demonstrate the conservation of tolerance to the ecological factors studied in the seeds of second-generation plants. Cross-resistance to pollutants was observed in some cases. The plants obtained can be recommended for the remediation of heavy-metal contaminated soils in urban ecosystems.     

Utilization of Multi-Tasking Non-Edible Plants for Phytoremediation and Bioenergy Source-A Review

Heavy metal contamination of land and freshwater resources is a serious concern worldwide. It adversely affects the health of animals, plants and humans. Therefore, remediation of toxic heavy metals must be highly considered. Unlike other techniques, phytoremediation is a holistic technology and can be used in large scale for soil remediation as it is costless, novel, environmentally-safe and solar-driven technology. Utilization of non-edible plants in phytoremediation is an ingenious technique as they are used to generate new bioenergy resources along with the remediation of contaminated soils. Some nonfood bioenergy crops such as Salix species, Miscanthus species, Populus species, Eucalyptus species, and Ricinus communis exhibit high capability to accumulate various metals and to grow in contaminated lands. However, there are still sustainable challenges facing coupling phytoremediation with bioenergy production from polluted lands. Therefore, there has long been a need for developing different strategies to resolve such challenges. In this article review, we will discuss the phytoremediation mechanism, the technique of phytoremediation coupling with bioenergy production, sustainable problems facing linking phytoremediation with energy production as well as possible strategies to enhance the efficiency of bioenergy plants for soil decontamination by improving their characteristics such as metal uptake, transport, accumulation, and tolerance.     

Phytoremediation of Mercury- and Methylmercury-Polluted Soils Using Genetically Engineered Plants

Inorganic mercury in contaminated soils and sediments is relatively immobile, though biological and chemical processes can transform it to more toxic and bioavailable methylmercury. Methylmercury is neurotoxic to vertebrates and is biomagnified in animal tissues as it is passed from prey to predator. Traditional remediation strategies for mercury contaminated soils are expensive and site-destructive. As an alternative we propose the use of transgenic aquatic, salt marsh, and upland plants to remove available inorganic mercury and methylmercury from contaminated soils and sediments. Plants engineered with a modified bacterial mercuric reductase gene, merA, are capable of converting Hg(II) taken up by roots to the much less toxic Hg(0), which is volatilized from the plant. Plants engineered to express the bacterial organo-mercurial lyase gene, merB, are capable of converting methylmercury taken up by plant roots into sulfhydryl-bound Hg(II). Plants expressing both genes are capable of converting ionic mercury and methylmercury to volatile Hg(0) which is released into an enormous global atmospheric Hg(0) pool. To assess the phytoremediation capability of plants containing the merA gene, a variety of assays were carried out with the model plants Arabidopsis thaliana, and tobacco (Nicotiana tabacum).     

植物-微生物联合修复化学农药污染土壤的研究进展

化学农药的高毒性、生物积累性和扩散性极易对环境及人类健康造成危害,环境中化学农药的去除尤为重要。植物-微生物联合修复技术因其高效、环境友好和修复成本低等优点受到越来越多的关注,植物-微生物联合修复化学农药污染土壤是一种很有前景的方法。植物为根际和内生细菌提供养分,而细菌通过化学农药的降解和解毒来支持植物生长。本文综述了影响化学农药在植物体内吸收和转运的因素以及植物-微生物修复技术的原理,并讨论了植物与微生物在化学农药污染土壤修复中的协同效应,并对植物-微生物联合修复法在化学农药污染土壤修复中的应用前景进行了展望。     

Phytoremediation: an overview of metallic ion decontamination from soil

In recent years, phytoremediation has emerged as a promising ecoremediation technology, particularly for soil and water cleanup of large volumes of contaminated sites. The exploitation of plants to remediate soils contaminated with trace elements could provide a cheap and sustainable technology for bioremediation. Many modern tools and analytical devices have provided insight into the selection and optimization of the remediation process by plant species. This review describes certain factors for the phytoremediation of metal ion decontamination and various aspects of plant metabolism during metallic decontamination. Metal-hyperaccumulating plants, desirable for heavily polluted environments, can be developed by the introduction of novel traits into high biomass plants in a transgenic approach, which is a promising strategy for the development of effective phytoremediation technology. The genetic manipulation of a phytoremediator plant needs a number of optimization processes, including mobilization of trace elements/metal ions, their uptake into the root, stem and other viable parts of the plant and their detoxification and allocation within the plant. This upcoming science is expanding as technology continues to offer new, low-cost remediation options.