不同螯合剂和有机酸对苍耳修复镉砷复合污染土壤的影响

为了提高苍耳对农田Cd和As污染的修复效率,探究了不同螯合剂和有机酸（EDTA、SAP、CA和MA）对苍耳提取农田土壤Cd和As的影响.结果表明,施用4种不同螯合剂和有机酸对苍耳的根、茎和叶生物量影响不大.不同螯合剂和有机酸对苍耳各器官Cd和As含量和积累量影响不同.与CK处理相比,施用EDTA、SAP、CA和MA均显著提高了苍耳叶部的Cd含量,增幅分别是44.1%、32.4%、41.2%和38.2%,苍耳根系As含量分别提高89.6%、7.4%、94.8%和61.5%.施用EDTA、SAP、CA和MA处理使苍耳植株总Cd积累量分别比CK处理提高70.2%、29.4%、28.9%和33.1%,而As积累量分别提高67.0%、19.6%、81.9%和40.8%.施用螯合剂和有机酸对苍耳各器官Cd和As的富集系数和转运系数也有不同影响.4种螯合剂和有机酸处理对根际土壤Cd和As含量影响均比较显著,与对照相比降幅分别是32.7%~38.2%和14.6%~20.5%.4种螯合剂和有机酸均可以提高苍耳提取农田土壤Cd和As的效率.     

Ability of Poplar (Populus spp.) to Detoxify Chloroacetanilide Herbicides

The ability of poplar trees to resist chemical stress caused by chloroacetanilide herbicides was studied. Detached leaves of Lombardy poplar (Populus nigra L.) were exposed to seven chloroacetanilide herbicides via uptake through the cut petiole. The leaves showed high tolerance against the phytotoxicity of these compounds. Their tolerance was further enhanced by treatment with 2-oxothiazolidine-4-carboxylic acid (OTC, a precursor of the amino acid cysteine). High levels of glutathione (GSH) and GSH S-transferase (GST) activity were detected in poplar leaves. Treatments with chloroacetanilide herbicides left the GSH content in the leaves unchanged but strongly induced the GST activity. In contrast, in OTC-treated leaves increased GSH contents were measured, but GST activities remained unchanged. It therefore appears that a highly active and inducible GSH-conjugation Phase II detoxification system in their leaves may make poplar trees useful for phytoremediation of soils contaminated with chloroacetanilide herbicides. Based on these findings a phytoremediation project using different poplar hybrids at a site heavily polluted with such compounds in Hungary has been launched.     

化学与工程措施强化重金属污染土壤植物修复

作为植物修复的辅助措施,化学方法强化与工程技术强化能有效提高土壤重金属污染的修复效率.综述了化学方法与工程技术强化重金属污染土壤植物修复的研究进展,重点讨论了络合强化技术和基因工程技术用于强化植物修复的基本原理、相关化学物质或基因、主要技术步骤、存在问题以及解决方法,并在此基础上提出了今后研究的展望.     

矿区废弃地重金属的植物修复技术研究进展

文章从矿区废弃地重金属污染土壤的现状及其对环境的影响入手,综述了植物修复技术用于矿区重金属污染修复与治理的机理、超富集植物筛选研究进展,提出实际应用中超富集植物的筛选原则:植物体内重金属的临界含量高低、植株的生物量大小、叶绿素含量的高低及根系转运能力的大小。指出了植物修复在投资、建设、运行管理及其环境效应方面的优势性与耐受植物种类及修复速率等方面存在的局限性。最后,展望了植物修复在矿区废弃地重金属污染修复中的研究与应用前景。     

不同有机物料对东南景天修复重金属污染土壤效率的影响

通过盆栽试验,研究清洁有机物料(沼渣、菌渣、笋壳)对镉、锌超积累植物东南景天修复重金属污染程度不同的土壤(分别采自温州和富阳,称温州土和富阳土)的影响.结果表明,有机物料对土壤重金属有效性的影响因有机物料种类和添加量而异,不同重金属元素的反应也不同.在温州土中,以5%沼渣对Cu、Zn的活化效果最好;而在富阳土中则以1%笋壳对Cu、Zn、Pb和Cd的活化效果最好.有机物料的添加促进了东南景天的生长,其生物量随着有机物料添加量的提高而增加,增幅达23.7%~93.0%.在温州土中,仅以1%笋壳的处理对东南景天地上部吸收积累Cd的效果最佳,超过对照的22.6%,而其余各处理皆不及对照;对于Zn,菌渣处理不及对照,而其它处理均优于对照,以5%沼渣、1%笋壳和5%笋壳为佳,分别超过对照的39.6%、32.6%和23.8%.而在富阳土中,对于Cd而言,以5%笋壳、1%沼渣和5%沼渣的处理效果为佳,地上部Cd积累量超过对照的12.9%、12.8%和6.2%,而其余处理皆不及对照;对于Zn,添加有机物料的各处理都促进了东南景天地上部Zn的积累,最佳处理分别为:5%笋壳、5%沼渣和5%菌渣,分别超过对照的38.4%、25.7%和22.4%.     

Constitutional tolerance and chlorophyll fluorescence of Boehmeria nivea L in response to the antimony (Sb) and arsenic (As) co-contamination

The metal tolerance and metabolic changes in Boehmeria nivea colonized in mining areas are not well known. A hydroponic experiment was conducted to evaluate the impact of antimony (Sb)+arsenic (As) in following combinations (control (no metal), 20+0, 10+10, 40+0, 20+20, and 40+40 mg/L) on phytotoxicity, metal tolerance index (MTI), and chlorophyll fluorescence in B. nivea. This constitutes an initial investigation of metal tolerance and chlorophyll fluorescence in Sb and Sb+As contaminated B. nivea. The high Sb+As 40+40 mg/L produced significant phytotoxicity and MTI in the plant. Progressive higher Sb and Sb+As levels resulted in decreased chlorophyll fluorescence of B. nivea. Exposure to intermediate and high Sb+As levels induced damage in the photosynthesis apparatus of the plant.     

部分植物富集镉能力探讨

综述了农作物、油料作物、蔬菜、水果、杂草和树木等植物富集镉的不同情况,指出了现在研究植物富集镉能力的弊端,提出寻找自然生长在镉污染区生物量大的耐镉植物是植物修复镉污染土壤的一条重要途径。     

蜈蚣草生长对其根际铜尾矿土壤酶活性的影响

通过盆栽模拟试验,研究了蜈蚣草(Pteris vittata)生长对其根际铜尾矿土壤酶活性的影响。结果表明,蜈蚣草根际土壤中过氧化氢酶、脲酶、多酚氧化酶和蔗糖酶活性均随着植物的生长而呈现不同程度的升高,其中过氧化氢酶和脲酶活性均与植物生长时间之间呈显著正相关,多酚氧化酶和蔗糖酶活性在植物生长旺盛期达到峰值,分别为对照组的3.59和2.58倍,随后逐渐下降;而磷酸酶活性却随着植物的生长而显著降低。过氧化氢酶、脲酶和磷酸酶活性与蜈蚣草地下部分干质量的相关性大于其地上部分,且5种土壤酶活性与土壤有机质含量之间相关显著。蜈蚣草生长可有效改善根际铜尾矿的基质环境和根际土壤肥力水平,因此,在铜尾矿废弃地恢复实践中具有较大的应用潜力。     

Phytoremediation of Soil Polluted by Nickel Using Agricultural Crops

Soil pollution due to heavy metals is widespread; on the world scale, it involves about 235 million hectares. The objectives of this research were to establish the uptake efficiency of nickel by some agricultural crops. In addition, we wanted to establish also in which part of plants the metal is stored for an eventual use of biomass or for recycling the metal. The experiments included seven herbaceous crops such as: barley (Hordeum vulgaris), cabbage (Brassica juncea), spinach (Spinacea oleracea), sorghum (Sorgum vulgare), bean (Phaseolus vulgaris), tomato (Solanum lycopersicum), and ricinus (Ricinus communis). We used three levels of treatment (150, 300, and 600 ppm) and one control. At the end of the biological cycle of the crops, the different parts of plants, i.e., roots, stems, leaves, fruits, or seeds, were separately collected, oven dried, weighed, milled, and separately analysed. The leaves and stems of spinach showed a very good nickel storage capacity. The ricinus too proved to be a very good nickel storer. The ability of spinach and ricinus to store nickel was observed also in the leaves of cabbage, even if with a lower storage capacity. The bean, barley, and tomato, in decreasing order of uptake and storage capacity, showed a high concentration of nickel in leaves and stems, whereas the sorghum evidenced a lesser capacity to uptake and store nickel in leaves and stems. The bean was the most efficient in storing nickel in fruits or grains. Tomato, sorghum, and barley have shown a storage capacity notably less than bean. The bean appeared to be the most efficient in accumulating nickel in the roots, followed in decreasing order by sorghum, ricinus, and tomato. With regard to the removal of nickel, spinach was the most efficient as it contains the highest level of this metal per gram of dry matter. The ricinus, cabbage, bean, sorghum, barley, and tomato evidenced a progressively decreasing efficiency in the removal of nickel.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils. Bidens maximowicziana is a new Pb hyperaccumulator, which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb. The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues. The Pb distribution order in the B. maximowicziana was: leaf > stem > root. The effect of amendments on phytoremediation was also studied. The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application. Compared with CK (control check), EDTA application promoted translocation of Pb to overground parts of the plant. The Pb concentrations in overground parts of plants was increased from 24.23–680.56 mg/kg to 29.07–1905.57 mg/kg. This research demonstrated that B. maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil, especially, combination with EDTA.