共查询到19条相似文献,搜索用时 171 毫秒
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化学方法作为植物修复的辅助措施,能有效提高土壤重金属污染的修复效率。综述了化学方法强化重金属污染土壤植物修复的研究进展,重点讨论了螯合剂、表面活性剂和酸碱调节剂强化植物修复的作用机制及应用效果,并展望了今后的研究方向。 相似文献
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综述了在矿区土壤中重金属的污染修复过程中,植物修复作为最普遍且最经济的修复方法,被广泛使用。而在利用植物修复矿区重金属污染土壤过程中,重金属转运迁移直接影响到植物的修复效果。因此,明确矿区土壤中重金属转运迁移过程的影响因素非常重要。通过进一步分析矿区土壤中重金属迁移转化的影响因素时,发现矿区土壤中重金属的转运迁移不仅受到土壤中黏土矿物、化学螯合剂及其他化学过程等的作用,根际环境也对其也存在着很大的影响。进而总结出,在矿区污染土壤植物修复过程中,应当既考虑到土壤的理化性状,又要兼顾根际环境的影响作用。 相似文献
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土壤重金属污染联合修复技术研究进展 总被引:1,自引:0,他引:1
从土壤重金属污染治理的现状入手,介绍了以生物、物理、化学修复技术为基础的各联合修复体系,主要包括以植物修复为核心的微生物-植物、化学-植物、动物-植物、植物-植物以及以电动修复和化学淋洗为核心的各种联合修复体系。结果表明,相对于单一重金属污染修复技术,联合修复体系可显著提高重金属污染土壤的修复效率,尤其是以植物修复为核心的联合修复技术,以其低能耗、环境友好等优势,具有良好的发展潜力和应用前景。分析了目前土壤重金属修复过程中存在的问题,并对今后的研究方向进行展望。 相似文献
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植物—微生物联合修复重金属污染土壤研究进展 总被引:1,自引:0,他引:1
本文概述了土壤重金属污染的特点及现状的基础上,系统总结了土壤重金属污染修复现状,着重阐述几种植物—微生物联合修复技术在这方面的研究现状及存在的问题,以期为治理土壤重金属污染提供新的思路。 相似文献
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The corrosion and tribocorrosion of tungsten in 0.01 M H2SO4, without and with the presence of lactic acid and phosphoric acid as chelating agents was studied here.The passive behaviour was characterised using potentiostatic polarization and potential step techniques combined with rotating disk electrodes. Surface analysis techniques (XPS, AES) were used to assess surface chemistry. The tribocorrosion of tungsten was investigated using a tribometer equipped with an electrochemical cell operating at applied passive potentials of 0.2 V and 1.0 V.Under static corrosion conditions chelating agents were found to enhance passive film dissolution and to decrease the passive film thickness. Despite this, the effect of the investigated chelating agents was limited under tribocorrosion conditions. Indeed, only lactic acid at the most anodic potential lead to significant differences in material removal by impeding the formation of protective tungsten oxide tribolayers. The discrepancy on the effect of chelating agents in corrosion and tribocorrosion was explained in terms of the different involved time constants. 相似文献
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D. J. Turner 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1972,22(9):983-992
A method of using chelating agents for maintaining clean conditions in once-through boilers is considered in detail. It involves forming volatile, inner complexes with unwanted oxide material so that the metal ions can be carried through the turbine and, after condensation of the steam, be removed by ion exchange. Potentially suitable agents are considered from the point of view of thermal stability and corrosion risk; also thermodynamic stability and volatility of their complexes. Most chelating agents available in commercial quantity appear to be unsuitable but oxine (8-hydroxy quinoline) at least, seems satisfactory and worth investigating further. Oxine, along with certain other aromatic chelating agents, should be able to prevent the formation of metal-oxide debris in high pressure drum boilers. 相似文献
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络合剂作为一种常用的助剂,由于其能提高加氢催化剂的性能而得到了研究者的重视。本文综述了络合剂对加氢催化剂加氢性能的影响,总结了引入络合剂后催化剂硫化行为方面的研究进展。简要介绍了络合剂的加入对金属浸渍液性质与催化剂加氢活性的影响,及采用共浸渍和分步浸渍引入络合剂时络合剂不同的作用机理。总体来看,络合剂的添加可以延迟助剂Ni(Co)的硫化,降低Mo(W)的硫化温度,进而提高Mo(W)的硫化程度,减弱活性组分与载体的相互作用,增强了活性组分的分散性,最终提高了催化剂的加氢脱硫活性。最后指出对络合剂改性的加氢脱硫催化剂在作用机理、工业催化领域等方面的研究是未来的研究方向。 相似文献
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针对高密度聚乙烯(HDPE)合成树脂,采用多种国产高效抗氧化稳定剂、热加工稳定剂,同时配以加工润滑剂和分散剂改善助剂分散性及树脂加工性,进行HDPE树脂用多功能复合助剂的研制。实验表明:该多功能复合助剂中各单剂间存在协同效应,不同比例的用量直接影响树脂的抗老化性能。 相似文献
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Bulman RA 《Metal-Based Drugs》1994,1(2-3):87-106
Up to about the early 1980s it was perhaps still possible to summarize in a review of a moderate length the development of the medicinal applications of chelation chemistry and the exploitation of such chemistry in regulating the metal ion concentrations in the body. However, in the last few years there has a great surge in the development of chelation chemistry and its usage in medicine and related areas of life sciences research. It is no longer the case that such a review primarily concentrates upon the use of chelating agents in removing toxic metals from the body but it must now cover the use of chelating agents in the imaging procedures nuclear medicine and magnetic resonance imaging (MRI), the use of chelating agents in unravelling the biochemistry of reactive oxidative species (ROS) and the control and measurement of intracellular calcium ions. It is in the recent applications that there have been the greatest developments over the last ten years. 相似文献
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Macromolecular chelating agents have been synthesized and investigated for the complexation with various metals in homogeneous phasing using membrane filtration. Quite a number of water-soluble basis polymers such as poly(vinylamine), poly(acrylic acid), poly(ethyleneimine), and copolymers, and their derivatives are listed and discussed in respect to their application for the chelation of transition metals. The polymers had molecular masses between 20000 and 200000 daltons. The application of membrane filtration rendered it possible to separate excess metallic ions from the polymer chelate in a continuous or discontinuous process. Studies on the metal-binding capacity of the polymer ligand exhibited the possiblity of preparation of macromolecular chelating agents which are selective for different metals. There after, the introduction of chelating groups such as iminodiacetic acid, thiourea, pyridine-2-aldimine, and others, improved significantly the selectivity for the metals copper, nickel, palladium, mercury, iron, gold, and platinum. For the regeneration of the polymer ligands electrolysis and protolysis can be used. The macromolecular chelates remained water-soluble independent of the chelated metal and the polymeric chelating agent. According to these studies, certain metals can be removed selectively from waste water or other diluted solutions in homogeneous phase by the application of polymeric chelating agents. 相似文献