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1.
南京市14种绿化树种对空气中重金属的累积能力   总被引:8,自引:0,他引:8  
分析了南京化工厂(污染区)和江苏省林科院(对照区)不同绿化树种叶片重金属元素(Pb、Cd和Cu)的含量,揭示了14种绿化树种对3种重金属污染物的累积能力。结果表明,城市绿化树种对大气重金属污染物具有一定的吸收净化能力,并依重金属和树种的不同具有明显差异;同种植物对不同重金属的累积量也有很大差别,其中对Cu的累积量最高;采样区植物叶片重金属含量明显高于对照区;对Pb累积量高的树种有:杨树、广玉兰、女贞和紫叶李; Cd累积量高的树种为杨树;Cu累积量高的树种为构树;累积3种重金属综合能力最强的树种有杨树、构树、雪松、广玉兰、悬铃木、栾树。  相似文献   

2.
基因工程改良植物重金属抗性与富集能力的研究进展   总被引:5,自引:1,他引:5  
基于分子水平上对植物吸收、解毒、忍耐以及超富集重金属的几个关键步骤的认识,以及一些功能基因相继在细菌、酵母、植物和动物中被分离、鉴定,近年来,人们利用转基因技术提高植物重金属抗性和富集能力方面已获得进展, 一些功能基因(如gsh1, MerAArsC)及其工程植物已显示出植物修复产业化潜力。特别对转基因技术所采取的分子生物学途径、达到的效果以及存在的问题进行了详述,对今后研究的重点和策略进行了探讨。  相似文献   

3.
利用乙二胺四乙酸淋洗修复重金属污染的土壤及其动力学   总被引:32,自引:0,他引:32  
通过室内模拟试验,采用振荡淋洗的方法研究了乙二胺四乙酸(EDTA)浓度、pH、淋洗时间对重金属去除效果的影响.利用一级反应动力学模型对试验数据进行拟合,并测定了EDTA处理前后土壤中重金属形态的变化.结果表明,EDTA溶液在浓度为0.1 mol·L-1、pH 7、淋洗时间1 d的条件下能达到对污染土壤重金属的最大去除率,去除率分别为Cd 89.14%、Pb 34.78%、Cu 14.96%、Zn 45.14%.模型拟合结果表明,Cd的质量转移系数最大,其次是Zn、Pb和Cu.说明在土壤淋洗过程中,Cd和Zn最先达到质量转移的平衡状态,然后是Pb和Cu.形态分级结果表明,EDTA能有效地去除交换态、碳酸盐结合态和氧化物结合态重金属,而对有机态和残余态部分重金属作用效果不明显.  相似文献   

4.
废旧橡胶颗粒填充草坪根带基质及草坪植物生态响应   总被引:4,自引:0,他引:4  
选择4种不同粒径大小的废旧橡胶颗粒分别与壤土、粘土、沙土组配草坪基质,通过组配基质构建草坪建植体系,研究了草坪植物的生态响应。通过对各生态指标综合效应分析,结果表明:壤土组配基质中,胶粒粒径为0.5~1 mm与4~6 mm组配基质要好于1~2 mm和2~4 mm组配基质;粘土组配基质中,1~2 mm胶粒组配基质为最好;对于沙土组配基质,1~2 mm和2~4 mm粒径的胶粒组配基质要优于0.5~1 mm与4~6 mm的组配基质。比较发现,从草坪植物生长角度来看,以沙土填充废胶粒为介质组配运动场草坪基质具有较好的应用前景。  相似文献   

5.
The application of chelating agents for phytoextraction has demonstrated that it is an efficient method to activate heavy metals in polluted soil. We conducted pot experiments using soybean, which has been considered an indicator plant, to study the effects of EDTA and EDDS on heavy metals’ activation, and on the soybean. The study results indicated that EDDS decreased the chlorophyll content of the leaves and increased the malondialdehyde (MDA) content of the soybean. EDTA also decreased the chlorophyll content of the leaves. EDDS had a strong influence on activating Cu (2583-8900-fold) and Zn. The addition of 5 mmol kg?1 of EDDS markedly increased the uptake of metals. Compared with the control, EDDS increased the Cu uptake (100-205-fold). EDTA greatly increased the activation of heavy metals; it also increased Cu uptake in a concentration-dependent manner. EDTA also increased the biological concentration factor (BCF) and the transfer factor (TF) in a concentration-dependent manner. The BCF and the TF reached maximum levels when 5 mmol kg?1 EDDS was applied to the pots.  相似文献   

6.
谢斐  张朝晖 《植物研究》2011,31(1):117-120
通过对湘西茶田钒矿废弃冶炼厂矿渣上葫芦藓的野外生态调查和采集,利用原子吸收光谱仪、电感耦合等离子发射光谱仪和原子荧光光谱仪分析了葫芦藓配子体和孢子体及其基质重金属含量。结果表明葫芦藓配子体和孢子体富集了大量的重金属,各重金属元素在配子体和孢子体间的富集存在较大的差异,配子体比孢子体显著富集重金属元素(p<0.05),Zn和Mn在葫芦藓植物体中比其他重金属元素更高。同时也讨论了重金属在苔藓植物中的富集及生物阻抗的作用。  相似文献   

7.
The results esults of a survey of heavy metal contamination at Cleveland area brownfields and public spaces are presented. Soils were analyzed using a 24?h, 1N HCl extraction procedure. The study was conducted to seek brownfield soils that manifest properties of “old” sequestered contamination and to develop a better understanding of the nature and extent of heavy metal burdens at brownfield sites in the Greater Cleveland area. The results indicated that Cleveland brownfields commonly yield soil burdens well above remediation triggers for residential soils and often yield values above industrial remediation triggers. It was also discovered that public areas in the vicinity of brownfields commonly have heavy metal contamination significantly above background levels and occasionally above residential remediation triggers. These results indicate that brownfields redevelopment initiatives should proceed with caution. The appropriate remediation goals or restrictions must be imposed to control urban exposure to heavy metal contamination.  相似文献   

8.
A pot experiment was conducted to study the performance of EDTA and citric acid (CA) addition in improving phytoextraction of Cd, Cu, Pb, and Cr from artificially contaminated soil by T. angustifolia. T. angustifolia showed the remarkable resistance to heavy metal toxicity with no visual toxic symptom including chlorosis and necrosis when exposed to metal stress. EDTA-addition significantly reduced plant height and biomass, compared with the control, and stunted plant growth, while 2.5 and 5 mM CA addition induced significant increases in root dry weight. EDTA, and 5 and 10 mM CA significantly increased shoot Cd, Pb, and Cr concentrations compared with the control, with EDTA being more effective. At final harvest, the highest shoot Cd, Cr, and Pb concentrations were recorded in the treatment of 5 mM EDTA addition, while maximal root Pb concentration was found at the 2.5 mM CA treatment. However, shoot Cd accumulation in the 10 mM CA treatment was 36.9% higher than that in 2.5 mM EDTA, and similar with that in 10 mM EDTA. Shoot Pb accumulation was lower in 10 mM CA than that in EDTA treatments. Further, root Cd, Cu, and Pb accumulation of CA treatments and shoot Cr accumulation in 5 or 10 mM CA treatments were markedly higher than that of control and EDTA treatments. The results also showed that EDTA dramatically increased the dissolution of Cu, Cr, Pb, and Cd in soil, while CA addition had less effect on water-soluble Cu, Cr, and Cd, and no effect on Pb levels. It is suggested that CA can be a good chelator candidate for T. angustifolia used for environmentally safe phytoextraction of Cd and Cr in soils.  相似文献   

9.
The results of analyses conducted to determine contents of Cd(II) and Pb(II) in mushrooms of mycorrhizal fungi and selected parts of birches growing in an industrial desert surrounding a nonferrous works are presented in this study. The fruiting bodies of fungi accumulated several times higher contents (up to 80 μg g−1 dry weight) of Cd(II) compared to those found in the soil (20 μg g−1 dry weight). In contrast, the mushroom contents of Pb(II) were only slightly increased (up to 895 μg g−1 dry weight) than those present in the soil (500 μg g−1 dry weight). However, fivefold higher concentrations of the metals were found in the mycorrhizal roots. Comparing the distribution of the metals analysed, the protective role of the ectomycorrhizae in relation to the host tree was indicated. Mycorrhizal fungi persistently fixed heavy metals, forming an efficient biological barrier that reduced movement of the metals in birch tissues.  相似文献   

10.
以不同淋洗方式处理后的生活垃圾堆肥为基质进行草坪植物培植,研究了高羊茅的生理生态响应。结果表明,淋洗处理堆肥中高羊茅的发芽率及株高等生长指标均优于未淋洗的原堆肥对照组,其中水肥淋洗比例为1∶1的处理中,高羊茅的最大发芽率比对照提高89.6%。通过对超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)3种保护酶的活性及脯氨酸和丙二醛(MDA)含量等指标的测定可以看出,经淋洗处理后的堆肥基质对草坪植物的胁迫程度均小于原堆肥,更有利于草坪植物的正常生长。综合高羊茅生长指标及生理指标来考虑,堆肥处理的最佳淋洗比例为水∶堆肥的质量比为2∶1。  相似文献   

11.
大型水生植物对重金属的富集与转移   总被引:27,自引:0,他引:27  
潘义宏  王宏镔  谷兆萍  熊国焕  易锋 《生态学报》2010,30(23):6430-6441
通过野外调查和室内分析,研究了云南阳宗海南北两区域自然生长的17种水生植物的生长状况及植物和对应水样、根区底泥中重金属(As、Zn、Cu、Cd、Pb)的含量。结果表明:植物长势良好,未发现受害症状。水体As严重污染,Pb轻度污染,Zn、Cu和Cd均未超标。9种沉水植物同时对As、Zn、Cu、Cd、Pb的富集系数(植物全株重金属含量与水中该元素含量的比值)远大于1,具有共富集特征。在平均含As0.175mg/L的水中,金鱼藻、黑藻、小眼子菜、八药水筛全株As平均含量分别为(150±7.3)、(179±35)、(92±31)、(265±21)mg/kg(干重),对As具有较强富集能力;对于8种湿生和挺水植物,北部采样点的喜旱莲子草、田栖稗、细叶小苦荬和长芒稗对As,长芒稗、细叶小苦荬、圆果雀稗、水蓼和风车草对Cd,海芋和圆果雀稗对Zn的富集系数(植物地上部重金属含量与底泥中该元素含量的比值)以及圆果雀稗对Cd和Zn转移系数(植物地上部重金属含量与根中该元素含量的比值)均大于1。聚类分析结果表明,金鱼藻、黑藻、八药水筛、小眼子菜、穗状狐尾藻5种水生植物同时对As、Zn、Cu、Cd、Pb具有较强的吸收和富集能力,在重金属复合污染水体修复中具有较大潜力。  相似文献   

12.
Selecting plant species that can overcome harsh soil and microclimatic conditions and speed the recovery of degraded minelands remains a worldwide restoration challenge. This study evaluated the potential of three woody species and various organic and inorganic fertilization treatments for revegetating abandoned metalliferous mines in Korea. We compared survival, growth, and heavy metal uptake of species common to Korean minelands in two spoil types and a reference forest soil. Substrate type and fertilization both influenced seedling growth and metal concentrations substantially, but they had little effect on seedling survival. Fertilization increased the growth of all three species when grown in mine spoils but influenced the growth of seedlings grown in forest soil only marginally. Initial seedling survival and growth indicate that the study species can tolerate the heavy metal concentrations and other soil constraints of metalliferous spoil types. We estimate that plants can stabilize 2–22% of various heavy metals contained in spoil materials into plant biomass during 20 years of plantation growth. Combined with the erosion control and site amelioration benefits of mineland reforestation, stabilization of heavy metals in forest biomass justifies this treatment on abandoned Korean metalliferous mines.  相似文献   

13.
基于近20年的大量相关资料,综述了重金属对蛙蟾类毒性影响方面的研究,介绍了实验动物和实验方法,综合了重金属对蛙蟾类在形态、器官、组织、细胞和分子水平上毒害的主要表现,从重金属致毒过程、环境因素、物种、发育、重金属积累、联合毒性等角度初步分析了重金属对蛙蟾毒性大小的影响因素和毒性作用的主要机理,归纳了蛙蟾的几种抗毒/解毒/避毒反应,对开展进一步的研究提出建议.  相似文献   

14.
Constructed tide tanks were used to examine the accumulation and distribution of heavy metals in various components of a simulated mangrove ecosystem. Young Kandelia candel plants grown in mangrove soils were irrigated with wastewater of various strengths twice a week for a period of one year. The amounts of heavy metals released via tidal water and leaf litter were monitored at regular time intervals. The quantities of heavy metals retained in mangrove soil and various plant parts were also determined. Results show that most heavy metals from wastewater were retained in soils with little being uptake by plants or released into tidal seawater. However, the amounts of metals retained in plants on a per unit dry weight base were higher than those in soils as the biomass production from the young mangrove plants was much smaller when compared to the vast quantity of soils used in this study. A significantly higher heavy metal content was found in roots than in the aerial parts of the mangrove plant,indicating that the roots act as a barrier for metal translocation and protect the sensitive parts of the plant from metal contamination. In both soil and plant, concentrations of Zn, Cd, Pb and Ni increased with the strengths of wastewater, although the bioaccumulation factors for these metals decreased when wastewater strengths increased. These results suggest that the mangrove soil component has a large capacity to retain heavy metals, and the role of mangrove plants in retaining metals will depend on plant age and their biomass production. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

15.
早熟禾对4种重金属胁迫生长响应特征   总被引:10,自引:4,他引:10  
采用砂培法研究了早熟禾对不同浓度Cu2 、Zn2 、Cd2 和Pb2 胁迫的生长响应特征.结果表明,当Cu2 、Zn2 、Cd2 的浓度达100 m g/L时,早熟禾的种子萌发率、幼苗株高均有所下降,并随着胁迫浓度的增加,下降幅度增大;Pb2 对两指标的影响不太明显.Cu2 对根系及地上生物量具有抑制作用,尤其对根系生长抑制效应极为明显,当浓度增加到600 m g/L时,与对照相比,根长最高下降了96.67%.Zn2 、Cd2 和Pb2 在浓度超过200 m g/L时对早熟禾根系及地上生物量表现出抑制效应,并随着浓度的增加抑制效应增加.4种重金属对叶绿素的影响表现出一致的规律,即当浓度小于200 m g/L时对叶绿素的合成起促进作用,当浓度超过200 m g/L时,叶绿素的含量又随着处理浓度的增加而下降.  相似文献   

16.
Ling Li  Xuyu Yan  Juan Li  Yashan Tian  Pan Ren 《Phyton》2021,90(1):35-50
Heavy metal-contaminated soil is one of the major environmental pollution problems of agricultural production and human health in the world. Remediation of heavy metals in soil is one of the most popular research subjects. Different remediation strategies have been reported to remove heavy metals from contaminated soil, among which phytoremediation is the most important one. Compared with other major crops, cotton shows the strongest and most widespread resistance to abiotic stresses, such as heavy metals. Although heavy metal stress adversely affects the growth and development of cotton, cotton possesses a set of sophisticated stress-resistance strategies. As the main product of cotton is nonedible fibers, which have a large biomass and strong heavy metal absorption and enrichment capacities, cotton is an ideal crop to restore heavy metal-contaminated soils and has unique advantages in terms of both ecological and economic benefits, with great application prospects. In this review, based on domestic and foreign research results in recent years, the effects of heavy metals on cotton growth and product quality were analyzed, the heavy metal absorption, accumulation, translocation and enrichment characteristics of cotton plants were summarized, and the adaptation and tolerance mechanisms of cotton to heavy metals were explored. Furthermore, the view that cotton is an effective crop to remediate heavy metal pollution in farmland soil has been proposed, and popularization and application suggestions for planting cotton to repair heavy metal pollution have been put forward to provide a reference for the comprehensive evaluation of the economic feasibility of cotton to repair heavy metal pollution in farmland soil.  相似文献   

17.
A field experiment was conducted to evaluate the effective utilization of tannery sludge for cultivation of clarysage (Salvia sclarea) at CIMAP research farm, Lucknow, India during the year 2012–2013. Six doses (0, 20, 40, 60, 80, 100 tha?1) of processed tannery sludge were tested in randomised block design with four replications. Results revealed that maximum shoot, root, dry matter and oil yield were obtained with application of 80 tha?1of tannery sludge and these were 94, 113 and 61% higher respectively, over control. Accumulation of heavy metals (Cr, Ni, Fe, Pb) were relatively high in shoot portion of the plant than root. Among heavy metals, magnitude of chromium accumulation was higher than nickel, iron and lead in shoot as well as in root. Linalool, linalyl acetate and sclareol content in oil increased by 13,8 and 27% respectively over control, with tannery sludge application at 80 tha?1. Heavy metals such as chromium, cadmium and lead content reduced in postharvest soil when compared to initial status. Results indicated that clarysage (Salvia sclarea) can be grown in soil amended with 80 tha?1sludge and this can be a suitable accumulator of heavy metals for phytoremediation of metal polluted soils.  相似文献   

18.
Incubation tests were used to assess the effectiveness of three different organic residues and three different liming materials, alone or in combination, in the remediation of a mine contaminated soil. The organic residues tested were sewage sludge from a municipal wastewater treatment plant (SS), compost from the organic fraction of unsorted municipal solid waste (MSWC), and garden waste compost (GWC), applied at 100 and 200 Mg ha? 1. The liming materials tested were agriculture limestone (6.4 Mg ha? 1), calcium oxide (3.7 Mg ha? 1), and sugar beet sludge (12.2 Mg ha? 1) from the sugar manufacturing process. The soil and mixtures of soil and amendments were adjusted to 70% of the maximum water holding capacity and incubated for 28 days in a controlled-temperature room at 20°C ± 1°C. At the end of the incubation, samples were analyzed for pH, electrical conductivity, organic matter content, CaCl2-extractable, and' NH4Ac/HAc+ EDTA–extractable metal fractions (Cu, Zn, and Pb). Correlations among the variables and/or similarities among the treatments were identified by principal component analysis and hierarchical cluster analysis. The amendments tested decreased the CaCl2-extractable Cu and Zn fractions, considered as mobile metal fractions, to below analytical detectable limits, providing organic matter to the soil with levels between 1% and 2% at the end of the experiment, significantly different relatively to the original soil. pH and electrical conductivity reached high values when using 200 Mg ha? 1 SS or 200 Mg ha? 1 MSWC, with any of the liming materials tested, making these application rates excessive for this particular situation. Furthermore, the treatments using MSWC increased the NH4Ac/HAc+ EDTA–extractable Cu, Pb, and Zn fractions, considered as mobilizable metal fractions, as did the 200 Mg ha? 1 SS for Pb and Zn. Considering the overall results, the compost made from garden waste decreased metal solubility in the soil and increased soil pH and organic matter content, without the addition of large amounts of soluble salts, and without increasing the mobilizable metal content. Of the organic materials tested, this was the only one that can be considered adequate for remediation of the contaminated soil under study, at the application rates tested.  相似文献   

19.
金属矿区芒草种群对重金属的积累及其与土壤特性的关系   总被引:9,自引:0,他引:9  
通过分析大型综合金属矿区中经历不同污染强度与污染时间胁迫的芒草(Miscanthus sinensis)种群对4种主要重金属的积累状况,初步揭示芒草对这些重金属的积累特性与土壤重金属含量的关系。结果表明,1芒草根茎叶对4种重金属的的积累顺序为:根〉叶〉茎;2芒草对Cd、Pb的积累量与土壤中这两种重金属含量之间存在显著(P〈0.05)正相关关系;对Cu、Zn的积累量与土壤含量之间无显著相关,主要是因为土壤最高Cu与Zn含量已超过芒草对这两种元素积累所需的最大量,成为对芒草构成胁迫的主要因子。在该矿区的酸性条件下,芒草对Pb、Zn、Cu3种重金属的吸收率随pH值升高而升高,pH接近的样地,芒草的吸收率主要受土壤重金属含量的影响。结合各种群对四种重金属的积累状况判断,强度胁迫下的种群可能已发生耐性分化,从而产生较其它种群更强的耐重金属特性。总体上芒草是一种多重金属耐性植物,对这四种重金属的耐性顺序是:Cd〈Cu〈Zn-Pb。  相似文献   

20.
城市蔬菜的重金属污染及其对策   总被引:29,自引:0,他引:29  
通过对我国主要城市已开展的蔬菜重金属污染调查的回顾 ,对城市蔬菜的重金属污染现状的评价进行了比较 ,综合分析了造成城市蔬菜重金属污染的成因 ,并提出了几点降低和控制城市蔬菜重金属污染的对策。  相似文献   

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