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1.
Heavy metal pollution of soil is a significant environmental problem and has its negative impact on human health and agriculture. Rhizosphere, as an important interface of soil and plant, plays a significant role in phytoremediation of contaminated soil by heavy metals, in which, microbial populations are known to affect heavy metal mobility and availability to the plant through release of chelating agents, acidification, phosphate solubilization and redox changes, and therefore, have potential to enhance phytoremediation processes. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria have re-ceived more and more attention. This article paper reviews some recent advances in effect and significance of rhizobacteria in phytoremediation of heavy metal contaminated soils. There is also a need to improve our understanding of the mechanisms in-volved in the transfer and mobilization of heavy metals by rhizobacteria and to conduct research on the selection of microbial isolates from rhizosphere of plants growing on heavy metal contaminated soils for specific restoration programmes. 相似文献
2.
INTRODUCTION Biosphere pollution by heavy metals and nu-cleotides was accelerated dramatically during the last few decades due to mining, smelting, manufacturing, treatment of agricultural soils with agro-chemicals and soil sludge, etc. Problems associated with the contamination of soil and water such as animal wel-fare, health, fatalities and disruptions of natural eco-systems are well documented (He et al., 2005). Heavy metals such as Pb, Cr, As, Cu, Cd, and Hg, being added to our so… 相似文献
3.
Mycorrhizoremediation an enhanced form of phytoremediation 总被引：2，自引：0，他引：2
Khan AG 《Journal of Zhejiang University. Science. B》2006,7(7):503-514
Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soil and climates and their role in phytoremediation of contaminated soils. The arbuscular mycorrhizal fungi （AMF） are universal and ubiquitous rhizosphere mi- croflora forming symbiosis with plant roots and acting as biofertilizers, bioprotactants, and biodegraders. In addition to AMF, soils also contain various antagonistic and beneficial bacteria such as root pathogens, plant growth promoting rhizobacteria including free-living and symbiotic N-fixers, and mycorrhiza helping bacteria. Their potential role in phytoremediation of heavy metal （HM） contaminated soils and water is becoming evident although there is need to completely understand the ecological complexities of the plant-microbe-soil interactions and their better exploitation as consortia in remediation strategies employed for contaminated soils. These multitrophic root microbial associations deserve multi-disciplinary investigations using molecular, biochemical, and physiological techniques. Ecosystem restoration of heavy metal contaminated soils practices need to incorporate microbial biotechnology research and development. This review highlights the ecological complexity and diversity of plant-microbe-soil combinations, particularly AM and provides an overview on the recent developments in this area. It also discusses the role AMF play in phytorestoration of HM contaminated soils, i.e. mycorrhizoremediation. 相似文献
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INTRODUCTIONPhytoremediation,thatuseofgreenplantstodecontaminateCuandotherheavymetalsinsoils,isanemergingtechniquewithadvantagesofbeinginsitu,cost-effectiveandenvironmentallysus-tainable(Chanyetal.,1997;Cunninghametal.,1997;Saltetal.,1998).Theavailabilityofmetalinthesoilforplantuptakeisoneimportantlimitationforsuccessfulphytoremediation(Blaylocketal.,1997).Forexample,lead(Pb)isoneofthemostimportantenvironmentalpollutants,haslimitedsolubilityinsoils,andisavailableforplantuptakeduetocompl… 相似文献
5.
Phytoremediation is emerging as a potential cost-effective solution for remediation of contaminated soils, and bioavailability of metal in the soil for plant uptake is an important factor for successful phytoremediation. This study aimed at investigating the ability of EDTA and citric acid for enhancing soil bioavailability of Cu and phytoremediation by Elsholtzia splendens in two types of soils contaminated with heavy metals [i.e. mined soil from copper mining area (MS), and paddy soil (PS) polluted by copper refining]. The results showed that addition of 2.5 mmol/kg EDTA significantly increased the H2O extractable Cu concentration from 1.20 to 15.78 mg/kg in MS and from 0.26 to 15.72 mg/kg in PS, and that shoot Cu concentration increased 4-fold and 8-fold as compared to the control. There was no significant difference between the treatment with 5.0 mmol/kg EDTA and that with 2.5 mmol/kg EDTA, probably because that 2.5 mmol/kg EDTA was enough for elevating Cu bioavailability to the maximum level. As compared with the control, citric acid had no marked effect on both soil extractable Cu and shoot Cu concentration or accumulation. The results indicated that EDTA addition can increase the potential and efficiency of Cu phytoextraction by E. splendens in polluted soils. 相似文献
6.
Phytoremediation is emerging as a potential cost-effective solution for remediation of contaminated soils, and bioavailability
of metal in the soil for plant uptake is an important factor for successful phytoremediation. This study aimed at investigating
the ability of EDTA and citric acid for enhancing soil bioavailability of Cu and phytoremediation by Elsholtzia splendens
in two types of soils contaminated with heavy metals [i.e. mined soil from copper mining area (MS), and paddy soil (PS) polluted
by copper refining]. The results showed that addition of 2.5 mmol/kg EDTA significantly increased the H2O extractable Cu concentration from 1.20 to 15.78 mg/kg in MS and from 0.26 to 15.72 mg/kg in PS, and that shoot Cu concentration
increased 4-fold and 8-fold as compared to the control. There was no significant difference between the treatment with 5.0
mmol/kg EDTA and that with 2.5 mmol/kg EDTA, probably because that 2.5 mmol/kg EDTA was enough for elevating Cu bioavailability
to the maximum level. As compared with the control, citric acid had no marked effect on both soil extractable Cu and shoot
Cu concentration or accumulation. The results indicated that EDTA addition can increase the potential and efficiency of Cu
phytoextraction byE. splendens in polluted soils.
Project supported by the National Natural Science Foundation of China (No. 29977017) and the Science and Technology Ministry
of China (No. 2002CB410804) 相似文献
7.
ZHANG Ming-kui ZHENG Shun-an 《浙江大学学报(A卷英文版)》2007,8(11):1808-1815
Soils can often be contaminated simultaneously by more than one heavy metal. The sorption-desorption behavior of a metal in a soil will be affected by the presence of other metals. Therefore, selective retention and competitive adsorption of the soils to heavy metals can affect their availability and movement through the soils. In this study, the simultaneous competitive adsorption of four heavy metals (Cd, Cu, Hg, and Pb) on ten agricultural soils collected from the Changjiang and Zhujiang deltas, China was assessed. The results showed that the competition affected the behavior of heavy metal cations in such a way that the soils adsorbed less Cd and Hg, and more Pb and Cu with increasing total metal concentrations, regardless of the molar concen- tration applied. As the applied concentrations increased, Pb and Cu adsorption increased, while Cd and Hg adsorption decreased. The adsorption sequence most found was Pb>Cu>Hg>Cd. The maximum adsorption capacity for the heavy metal cations was calculated, and affected markedly by soil properties. The results suggest that Hg and Cd have higher mobility associated to the lower adsorption and that Pb and Cu present the opposite behavior. Significant correlations were found between the maximum adsorption capacity of the metals and pH value and exchangeable acid, suggesting that soil pH and exchangeable acid were key factors controlling the solubility and mobility of the metals in the agricultural soils. 相似文献
8.
重金属的排放造成了严重的环境问题。而消除重金属污染成为世界性的难题．有关研究结果表明。虽然重金属污染对植物有毒害作用，但是某些特殊植物具有从污染环境中吸收、转移以及积累重金属的潜能。从而修复土壤和水体等环境中的重金属污染．植物修复技术的出现虽然有很好的应用前景，但仍存在一些问题。 相似文献
9.
南京市城郊零散菜地土壤及青菜中重金属含量特征 总被引：4，自引：0，他引：4
丁爱芳 《南京晓庄学院学报》2003,19(4):28-31
采集了南京市城郊零散菜地土壤和青菜配对样品各18个,用原子吸收光谱仪测定了其中铜、锌、铅、镉的含量,结果表明:南京市城郊菜地土壤中Cu、Zn、Pb、Cd全量高于农区菜地土壤,Cu、Zn达到显著差异,重金属含量在土样之间有较大的变异性,反映了人为活动已对南京城郊土壤重金属产生了明显影响。城郊土壤上种植的青菜其可食部分重金属含量高于农区,尤其是对人体健康影响较大的Pb、Cd含量与农区相比存在显著差异,大大超过国家食品卫生标准。 相似文献
10.
重金属的开采和冶炼不仅破坏生态平衡,而且严重威胁人类的健康。以毕节地区2个铅锌矿为研究对象,采用现场采样、室内分析的方法,调查研究了该地区土壤及优势植物中重金属含量。结果表明：研究区土壤主要受到Pb、Zn、Cu、Cd四种重金属污染,其中,Cd污染最为严重,Pb、Zn为轻度污染。优势植物重金属含量测定表明,野艾蒿属于重金属富集型植物,苦苣菜属于规避型植物,马刺蓟属于根部囤积型植物。以上几种优势植物对重金属均具有一定的耐性,可以作为铅锌矿区弃地植物修复的优选物种。 相似文献
11.
化学淋洗法修复重金属污染土壤效果研究 总被引：6，自引：0，他引：6
在国内外相关研究的基础上,文章研究化学淋洗修复技术在重金属污染土壤修复方面的运用．用浓酸消解土样并用火焰原子吸收法测定土壤中重金属含量,选用土壤柱作淋洗实验,分析去离子水和EDTA溶液两种淋洗剂对Cu、Zn、Pb、Cd四种重金属的淋洗效率,并对化学淋洗修复效果进行比较． 相似文献
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13.
河南大学校园土壤中主要重金属状况及其评价 总被引：1，自引：0，他引：1
以河南大学校园的绿地、教学和生活区土壤中重金属和微量元素为研究对象,分析并评价了校园土壤中全量铜、锌、镍、铅、铬和有效态铜、锌、铁、锰、硼、钼的分布状况,污染程度及丰缺水平.结果发现:校园土壤除了锌污染严重之外,几乎没有重金属污染或重金属污染程度较低,并且重金属含量在绿地、教学和生活区存在一定的差异,表现出一定的随土地利用方式不同而变化的特点. 相似文献
14.
Physico-chemical characterization of a farmland affected by wastewater in relation to heavy metals 总被引：1，自引：0，他引：1
Emmanuel U. ONWEREMADU 《浙江大学学报(A卷英文版)》2008,9(3):366-372
This study investigated selected properties of soils affected by wastewater and its relationship with some heavy metals A free survey technique involving target sampling was used in siting soil profile pits. Soil samples were collected based on horizon differentiation and analyzed using routine and special analytical techniques. Soil data were subjected to correlation analysis using SAS program. Results show that all heavy metals studied had values above critical limits in the polluted soils using known standards and that these biotoxic metals decreased with soil depths. Highly significant （P=0.01 and 0.05） relationships were established between investigated heavy metals and some soil properties, especially soil pH and organic matter. Further studies involving more edaphic properties, biotoxic metals and their bioaccessibility in crops growing on wastewater soils will surely enhance knowledge and management of these highly anthropogenically influenced soils of the study site. 相似文献
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16.
了解豫灵土壤污染现状和筛选重金属富集植物对污染土壤进行修复,采用火焰原子吸收光度法对豫灵冶炼厂周边土壤中重金属含量进行了测定,并对7种植物铅、镉的吸收和富集能力进行了研究,结果表明：豫灵冶炼厂周边土壤中Pb、Cd的含量严重超标,分别为821.574mg/kg和62.207mg/kg。采集的7种植物样品对Pb、Cd的吸收能力存在明显差异,苦荬菜、茵陈蒿和播娘蒿对Pb、Cd的吸收能力均较强,植物体内Pb的含量分别为423.95、358.275和303.5mg/kg,Cd的含量分别为54.60、49.425、55.175mg/kg。茵陈蒿和播娘蒿属于杂草,适应性强,利用其对矿区土壤进行修复,不经人工干预即可正常生长,成本较低,因此可作为该污染区土壤修复的选择物种。 相似文献
17.
A laboratory incubation experiment was conducted to study the effect of copper as cupric sulfate (CuSO4.5H2O), and lead as lead acetate (Pb (OAc)2) on the size of the microbial biomass in red soil. The metals were applied, separately at six different levels: Cu at 50,
100, 200, 300, 400, and 600 μg·g−1 soil and Pb at 100, 200, 400, 600, 800, and 1000 μg·g−1 soil. In comparison to uncontaminated soil, the microbial biomass carbon (Cmic) and biomass nitrogen (Nmic) decreased sharply in soils contaminated with Cu and Pb. The microbial biomass C:N ratio in the metal contaminated soil was
observed to be considerably higher than that in untreated control. Between the two tested metals, Cu displayed greater biocidal
effect on microbial biomass carbon and nitrogen than Pb, showing their relative toxicity in the order: Cu≫Pb.
Project (No. 49671050) supported by National Natural Science Foundation of China.
Wa’el Mohamad—Former Ph. D. Student of Zhejiang University and is working in Ministry Of Agriculture (P. O. box. 2099), Amman,
Jordan. 相似文献
18.
在赣南18个脐橙产区县(市),根据不同土壤类型,选择具有代表性的果园约90个作为取样果园,采用BCR法对土壤样品的土壤重金属的形态进行分析,研究果园土壤中不同重金属元素的形态分布特征.结果表明:赣南脐橙果园土壤中生物有效性重金属形态含量所占比例从高到低依次为:Pb>Cu>Zn>Ni>Cr,同时,重金属元素Ni、Cu、Cr、Zn和Pb在不同类型土壤中的含量和形态分布规律基本一致,且均以残渣态为主,五种重金属元素的潜在环境风险都较小. 相似文献
19.
为了转染植物耐受和富集重金属相关基因提供合适的组织材料,同时为了建立大面积重金属污染的植物修复基地提供组培苗保障,实验以美洲商陆(Phytolacca americana L.)无菌苗的茎尖为外植体,通过选用不同生长素以及调节生长素浓度对外植体进行增殖,诱导芽和根的生长,建立了美洲商陆茎尖组织培养实验体系。诱导芽增殖的最佳培养基为:MS+0.1 mg/L 6-苄基腺嘌呤(6-BA)+0.1mg/L赤霉素(GA3)+300 mg/L水解乳蛋白(LH)+30 g/L蔗糖+9.0 g/L琼脂,pH5.8。诱导根增殖的最佳培养基为:1/2 MS+0.4 mg/L吲哚丁酸(IBA)+0.1 mg/L GA3+300 mg/L LH+15 g/L蔗糖+9.0g/L琼脂,pH5.8。采用该方法,萌发期和成苗期分别比文献报道缩短了5 d和6 d;建立了美洲商陆茎尖组织培养实验体系。 相似文献
20.
Heavy metal contamination of soils, derived from sewage irrigation, mining and inappropriate utilization of various agrochemicals and pesticides, and so on, has been of wide concern in the last several decades. The Shenyang Zhangshi Irrigation Area (SZIA) in China is a representative area of heavy metal contamination of soils resulting from sewage irrigation for about 30 years. This study investigated the spatial distribution and temporal variation of soil cadmium (Cd) and copper (Cu) contamination in the SZIA. The soil samples were collected from the SZIA in 1990 and 2004; Cd and Cu in soils was analyzed and then the spatial distribution and temporal variation of Cd and Cu in soils were modeled using Kriging methods. The results show that long-term sewage irrigation had caused serious Cd and Cu contamination in soils. The mean and the maximum of soil Cd are markedly higher than the levels in second grade standard soil (LSGSS) in China, and the maximum of soil Cu is close to the LSGSS in China in 2004 and is more than the LSGSS in China in 1990. The contamination magnitude of soil Cd and the soil extent of Cd con- tamination had evidently increased since sewage irrigation ceased in 1992. The contamination magnitude of soil Cu and the soil extent of Cu contamination had evidently increased in topsoil, but obviously decresed in subsoil. The soil contamination of Cd and Cu was mainly related to Cd and Cu reactivation of contaminated sediments in Shenyang Xi River and the import of Cd and Cu during irrigation. The eluviation of Cd and Cu in contaminated topsoil with rainfall and irrigation water was another factor of temporal-spatial variability of Cd and Cu contamination in soils. 相似文献