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1.
土壤盐渍化是在特定的自然和人类活动共同作用下产生的全球性土壤退化问题。丛枝菌根真菌(AMF)作为一种有益土壤微生物,在盐渍土壤中数量繁多、种类丰富,且能够与植物根系形成互惠共生体——丛枝菌根,从而提高植物耐盐性,进而改良盐渍土。在分析盐胁迫对植物影响机制的基础上,总结了AMF提高植物耐盐性的相关机制:(1)通过重建植物体内离子平衡,缓解盐离子毒害和改善植物体内营养平衡;(2)通过扩大植物根系吸收范围和提高渗透调节能力,缓解植物体内水分亏缺;(3)通过激活植物抗氧保护体系,抵抗氧化胁迫对植物造成的损伤,从而保护植物细胞膜系统和光合系统的完整性,提高植物耐盐性。最后,提出了AMF改善土壤盐渍化研究的不足与亟需解决的科学问题,以期为我国西北干旱区盐渍土的改良和土地生产力的提高提供理论指导,服务于国家建设"西部生态屏障"和"丝绸之路经济带"战略目标的实施。 相似文献
2.
根际环境重金属地球化学行为及其生物有效性研究进展 总被引：16，自引：1，他引：16
根际是土壤或滨岸沉积物中受植物根系及其生长活动影响的微域环境 ,具有特殊的物理、化学和生物性质 ,影响了重金属在根际环境中的分布、累积和生物有效性。从重金属在根际环境的分布与累积、地球化学赋存形态、生物有效性以及影响重金属根际行为和生物有效性的主要因素(温度、Eh和溶解氧、p H、根系分泌物、微生物 )、重金属根际吸收、富集、排斥和固定过程的调控、重金属耐性植物的筛选和培养 6个方面概述了近 1 0年来国内外在根际环境重金属地球化学行为及其生物有效性方面的主要研究进展 ,并指出了其存在问题以及今后的努力方向。 相似文献
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4.
金属矿区土壤重金属污染的植物修复研究现状 总被引：4，自引：0，他引：4
受矿业活动影响,金属矿区及周边土壤重金属污染已成为严重的环境问题之一。植物修复技术是近年来发展起来的清除土壤中重金属的一种有效、经济的生态技术。重金属污染土壤植物修复技术主要有植物固定、植物挥发和植物吸收等方式,植物固定技术是利用植物阻隔土壤中重金属的迁移,而植物挥发和植物吸收则是将土壤中的重金属移除。本文系统总结了迄今在金属矿区土壤重金属污染的植物固定和植物吸收修复技术研究方面的现状与进展,包括矿区超富集植物筛选、超耐受性植物筛选、提高重金属生物有效性的高效活化剂以及降低重金属迁移能力的化学钝化剂研究等。提出了当前相关领域研究中存在的主要问题,并提出了进一步研究的主要方向。 相似文献
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被污染土壤的植物修复研究 总被引：11，自引：1，他引：11
植物修复是利用植物吸收、降解、挥发、根滤、稳定、泵吸等作用机理,达到去除土壤、水体中污染物,或使污染物固定以减轻其危害性,或使污染物转化为毒性较低化学形态的现场治理技术.植物修复对于重金属污染土壤的治理修复具有重要意义.已有研究在累积与超累积植物的寻找筛选、植物对重金属等有害物的耐毒和解毒机理、植物修复现场环境调控及根际处理技术等方面取得了大量成果.现代分子生物学、基因工程技术发展有可能使植物修复技术取得重大突破. 相似文献
6.
近年来土壤污染问题日益严峻,特别是土壤中重金属污染对土壤肥力、植物生长都有着极大的威胁,为了了解pH值对土壤重金属污染的影响及提高测定的准确性,本文系统地分析了土壤pH值与重金属污染物之间的关系,分别讨论了土壤pH值对重金属污染物存在形态、转化迁移及污染治理三方面的影响,并针对土壤pH值测定过程中的影响因素,提出了相应的测定条件及操作方法以保证土壤pH值的准确测定。结果表明,土壤pH值对重金属存在形态、转化迁移及污染治理都有着极大的影响,是土壤重金属污染的重要影响因素,为重金属污染土壤的筛选、判断及后期治理提供参考。 相似文献
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《吉林大学学报(地球科学版)》2015,(Z1)
目前,矿山冶炼产生的重金属污染废水和尾矿对我国环境造成严重污染。湿地植物作为人工湿地的主要组成部分被成功应用于去除废水中的重金属(淹水条件),同时,湿地植物也成功被应用于矿山尾矿复垦(非淹水条件)。本研究在淹水和非淹水条件下,研究了十种常见湿地植物根部渗氧、重金属(Pb、Zn、Cd)吸收、根表和根际铁膜形成之间的关系,探讨不同水分处理引起的根际效应对湿地植物体内重金属积累转运以及生物量的影响。选取常见10种湿地植物品种,以广东大宝山重金属(Pb、Zn、Cd)污染土壤为生长介质,在淹水和非淹水条件下,采用根际袋法进行盆栽试验。研究发现,与非淹水条件相比,淹水处理能够显著提高同种湿地植物的生物量,根部渗氧量,根表和根际铁膜的厚度。淹水条件下,根表和根际铁膜厚度的增加也提高了根表和根际重金属(Pb、Zn、Cd)的吸附能力。虽然淹水处理也提高了植物的地上部分的生物量,但以整株湿地植物(地上部分,根,根表铁膜)为单位来计算,与非淹水处理相比,淹水处理显著提高了这十种湿地植物对Pb、Zn、Cd的累积量,它们分别为143%~4 161%,5.65%~1 637%,25.5%~474%。湿地植物的根部渗氧在淹水条件下对根表和根际重金属吸附重金属有重要作用,进而影响到湿地植物对重金属的吸收、转运和累积。 相似文献
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东南沿海是铅等重金属的地球化学高背景区。该地区广泛分布酸性红壤,酸雨沉降、不适当施肥导致土壤酸化以及由此引发土壤重金属生态风险令人关注。以福建省铁观音主产区为研究区,采集了79个茶园的表层和亚表层土壤样、茶叶样品,测定了重金属元素以及土壤常量元素和理化指标。研究表明,福建铁观音茶园土壤中Hg、Pb、Se、Zn高含量主要由地质背景所引起,土壤常量组分、有机质、酸碱度等理化条件对土壤元素含量有一定的影响;铁观音茶树老叶中As、Cd、Cr、Hg、Se、Pb、F等非植物营养元素含量明显高于嫩叶,显示这些元素随植物生长逐渐累积的特征,而嫩叶中植物生长必需的营养元素Cu、(Ni)、Zn则高于老叶,反映出微量营养元素在茶叶生长部位相对富集的特征;多数情况下土壤与茶叶间元素含量相关性差,说明茶树对土壤元素的吸收累积受到多种复杂因素的影响。研究表明茶叶与土壤Pb、Cr具有显著正相关性,为建立铅污染土壤生态效应预测评价模型提供了基础依据。 相似文献
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《城市地质》2020,(1)
矿产资源的开发利用引起的环境问题日益突出,矿区周边土壤的重金属污染已对生态环境、食品安全和人体健康构成了威胁。相比于传统的物理和化学修复技术,植物修复技术具有修复面积广、成本低廉、对土壤扰动小、操作方便管理简单、无二次污染等优点,因此受到广泛的关注。本文主要介绍了植物修复技术、超积累植物、富集系数、转运系数的概念及国内外关于超积累植物筛选的研究进展,重点总结了铅锌矿、煤矿、铁矿、铜矿、锰矿、金矿周边生长的典型修复植物,并论述了植物修复技术的作用机理,最后对矿区周边重金属污染土壤植物修复研究进行了总结,并对未来的发展方向提出了建议,以期为建立矿区人工植物修复系统,在矿区进行土壤重金属污染修复时选择合适的植物种类提供参考依据。 相似文献
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【研究目的 】镉、铬、铅、铜和锌等重金属是土壤中的典型有害元素。过量摄入会抑制生物体的生长发育。其在土壤中的分布受到原生地质背景成因和矿山开采、大气沉降、农药化肥施用等人类活动的共同影响。然而不同土地利用类型下的土壤重金属分布特征需要进一步识别,对于典型重金属的危害作用需要进行全面的梳理揭示。【研究方法 】通过查阅国内外的相关研究内容,整理典型重金属在土壤中的空间分布特征,总结土壤重金属对生物的影响作用,综述人体暴露在高重金属的土壤与地下水环境下的毒性作用及针对性修复方式。【研究结果 】受到原生地质背景和人类活动下土地利用类型的共同影响,造成土壤中重金属含量具有显著的空间变异性。重金属在土壤中的含量不同,会对土壤微生物与植物的生长发育产生不同效应的影响,并通过食物链进入人体累积。当重金属在人体中累积含量过高,会对人体的不同器官和系统产生破坏,威胁人体健康。【结论 】应该综合考虑污染方式、污染水平和暴露途径等因素进行针对性的重金属治理。 相似文献
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超富集植物与重金属相互作用机制及应用研究进展 总被引：3，自引：0，他引：3
社会发展过程中对矿产资源的勘查和开采利用所带来的重金属污染已对生态系统和人类健康造成严重威胁。超富集植物对重金属具有超富集、超耐受能力,是降低环境重金属污染、保障人类健康、实现绿色矿产勘查的有效途径,在植物修复、植物采矿和植物找矿中已获得了广泛应用。深入探索超富集植物的富集和耐受机制,揭示重金属-植物相互作用规律,提高植物对重金属的富集能力,是当前国际上研究热点。本文在简要介绍重金属对植物作用的基础上,阐述了重金属诱导氧化应激机制,重点关注重金属超富集植物富集机理研究,对其在解毒和耐受机制等领域的研究进展进行了评述。当前研究认为:(1)对超富集植物而言,根系分泌物与根际微生物的共同作用促进了重金属溶解,经共质体、质外体途径吸收后,重金属通过木质部向上转运,并隔离在液泡中,实现对重金属的超富集;(2)重金属通过与小分子有机酸、细胞壁、植物螯合肽结合,以及液泡隔离,可降低细胞质中游离金属离子浓度,增强植物耐受性;(3)重金属胁迫下,植物将激活多种特异性抗氧化酶,抵御氧化应激反应,实现对重金属的超耐受。(4)本文分析认为,植物中砷诱导的氧化应激反应机制可能是由砷的还原与甲基化过程及Haber-Weiss反应三部分构成。对重金属超富集植物的富集与耐受过程所涉及的生理与生化作用进行深入研究,揭示关键性影响因素与相关规律,寻找提升其特异性富集与指示能力的有效途径,将有助于超富集植物研究与应用向纵深发展。 相似文献
12.
Understanding how nutrient absorption processes in plants are related to arbuscular mycorrhizal (AM) association is critical for predicting the effects of AM symbiosis on elemental cycling for plants. Both mulberry (Morus alba) and Chinese prickly ash (Zanthoxylum bungeanum) are AM-associated plants, widely distributed in southwest China. It was hypothesized that if the nutrient absorption processes were efficiently associated with AM symbiosis in both mulberry and Chinese prickly ash, foliar nutrient concentrations—especially calcium (Ca)—would be primarily determined by the soil conditions in different regions. To investigate this, AM colonization levels of soils, nutrient levels in soils and leaves, and δ13C values of leaves were analyzed for mulberry and Chinese prickly ash. In this study, spore density in soils with low pH was higher than that in soils with high pH. The average concentrations of sugar delivered to roots in both mulberry and Chinese prickly ash in soil with relatively low pH and soil extractable cations were higher than those in other areas. The values of foliar δ13C in both mulberry and Chinese prickly ash in low soil-pH and soil extractable cations were lower than those in contrast areas, indicating that water availability was impacted by soil characteristics. The efficiency in AM-mediated processes might play an important role in translocation between soil nutrients and plant tissue. The results suggest uptake and translocation of nutrients, especially Ca, in AM-associated plants may be affected by an efficiency of AM-mediated processes. Since Sr does not appear to be similarly affected, expressing Ca and other nutrient concentrations relative to Sr could be used to evaluate whether the uptake and translocation of Ca and other nutrients are affected by AM-mediated processes. 相似文献
13.
Effects of Salt Stress on Plant and the Mechanism of Arbuscular Mycorrhizal Fungi Enhancing Salt Tolerance of Plants 总被引：1，自引：0，他引：1
Soil salinization is one of the global land degradation problems due to the impacts of climatic variations and human activities. As a beneficial soil microorganism, Arbuscular Mycorrhizal Fungi (AMF) are abundant in saline-alkaline land and form a mutual symbiosis with plants, which can improve salt tolerance of plant and reduce salt stress from the soil. Based on the mechanism of salt stress on the plant, the effects of AMF on plant physiological characteristics were introduced. Three main aspects of the AMF effects were summarized as follows: reconstructing the ion balance in plants to alleviate the toxic effects of specific ions; expanding the absorption range of plant roots and improving the osmotic regulation ability to alleviate the water deficit in plant; maintaining the integrity of cell membrane system and photosynthetic system to resist the damage caused by oxidative stress. Also, the future research direction in this field was evaluated, then a reference for the reconstruction of the saline-alkaline environment was provided. 相似文献
14.
通过测定植物果实中的氮元素含量,能够掌握植物生长状况,为提高优质果实的产量提供重要信息。目前分析测试植物果实中全氮的方法为传统凯氏定氮法,主要步骤为消解、蒸馏和滴定,消解时间约90min,蒸馏滴定时间约10～20min,分析测定过程较为繁琐,容易产生人为误差,不适于大批量植物果实样品的分析检测。为了缩短植物果实样品全氮的分析测定时间、提高工作效率,避免人为误差以及解决消解过程中样品飞溅和白烟逸出的问题,本文使用石墨消解仪对样品进行消解,加入浓硫酸和催化剂并加盖回流塞,使用全自动定氮仪进行分析测定,消解过程中样品不发生损失,白烟不逸出,消解时间约50min,蒸馏时间约3min,试剂消耗量小,相对误差和相对标准偏差均小于5%。本文建立的方法能够满足实验室快速、准确检测大批量植物样品中全氮的分析需求,已在中国地质调查局地调招标项目和河北省农用地土壤污染状况详查项目中得到了应用。 相似文献
15.
Pedo and biogeochemical studies of mafic and ultramfic rocks in the Mingora and Kabal areas,Swat, Pakistan 总被引：1，自引：0，他引：1
This study highlights the heavy metals (HMs) distribution in soils and their uptake by wild plants grown in the soils derived
from the mafic and ultramafic terrains. Plant and soil samples were analyzed for Cu, Pb, Zn, Cr, Ni and Cd using atomic absorption
spectrophotometer. The data indicate that almost all the HMs in the soil samples collected from the study area exceeded the
reference and normal agricultural soils. Greater variability was noticed in the uptake of HMs by various plants grown on the
studied soils. High concentrations of Cu and Zn in Cannabis sativa L. (seft hemp), Pb in Ailanthus altissima (Mill.) (Ailanto), Ni and Cr in Indigofrra gerardiana Wall. ex Baker (sage), and Saccharum griffihii Munro ex Boiss. (plume grass) were noticed among the studied plants. The multifold enrichments of Cr and Ni in the Indigofrra gerardiana and Saccharum griffihii as compared to the other plants of the study area suggested that these plants have the ability to uptake and translocate
high concentrations of Cr and Ni. The excessive concentrations of Cr and Ni in these plants can be used for mineral prospecting
but their main concern could be of serious environmental problems and health risks in the inhabitants of the study areas. 相似文献
16.
Accumulation and ecological effects of soil heavy metals in conventional and organic greenhouse vegetable production systems in Nanjing,China 总被引：2，自引：1，他引：1
Yong Chen Biao Huang Wenyou Hu David C. Weindorf Xiaoxiao Liu Lanqin Yang 《Environmental Earth Sciences》2014,71(8):3605-3616
The spatial variability of soil heavy metals in conventional and organic greenhouse vegetable production (CGVP and OGVP) systems can reveal the influence of different farming activities on their accumulation and plant uptake. This provides important basic data for soil utilization and pollution risk assessment. Based on horizontal and vertical spatial analysis, this paper presents the spatial variability and accumulation of soil heavy metals. The effects on plant uptake and factors influencing heavy metal accumulation are presented using the two typical greenhouse vegetable sites in Nanjing City, China as examples. Results showed that different greenhouse vegetable production systems had their own dominant heavy metal accumulation, specifically, Hg and Pb in CGVP system and Cd in OGVP system. The spatial analysis showed that horizontally, distribution of soil properties and heavy metal concentrations in the two sites showed decreases from specific regions to the periphery for organic matter (OM), Cd, Cu, Hg, Pb, and Zn in CGVP and OM, As, Cd, Cu, Hg, Pb, and Zn in OGVP. Vertically, soil properties and heavy metals mainly vary in the topsoil. The key factor for the accumulation was excess fertilizer input. Variation of soil properties and the accumulation of soil heavy metals significantly influenced heavy metal uptake by plants. However, accumulation risk varied according to different heavy metals and different plant species. Environmental management of these two kinds of production systems should pay more attention to fertilizer application, plant selection, and soil properties. 相似文献
17.
我国东部草原露天矿区土壤瘠薄,草场退化严重,生态恢复难度大。针对露天矿排土场的特殊环境,研究丛枝菌根真菌与沙棘的共生状况以及菌根对沙棘根系发育的影响和对排土场土壤的改良效应。试验发现,接菌组(+M)沙棘的株高和冠幅比对照组处理(CK)分别提高了20%和21%,+M的根长和根体积分别为CK的1.46倍和1.97倍;+M中沙棘根际土中的易提取球囊霉素含量为3.22 mg/g,显著高于CK的2.16 mg/g;+M的磷酸酶活性是CK的1.76倍,速效磷含量也有相似变化规律。研究结果表明,利用微生物促进露天矿排土场的土壤改良及生态恢复具有较强的可行性,对矿区生态系统的恢复具有重要意义。 相似文献
18.
白云鄂博矿区土壤和植物中稀土元素的分布特征 总被引：2，自引：1，他引：1
白云鄂博矿区是稀土的主要产出地,在矿山开采和选炼等过程中,稀土元素通过迁移、富集等作用进入植物体,研究稀土元素的分布特征和迁移规律,可为白云鄂博矿体闭坑后的生物修复提供数据支持。本文设置了7个土壤采样点,采集铁花、沙蒿、沙打旺、沙朋、青蒿、小叶杨、猪毛菜七种植物,用电感耦合等离子体质谱法测定土壤和植物的根、茎、叶及整株的稀土含量,研究稀土元素在土壤和植物中的分布特征和迁移规律。统计分析结果表明:随着采样区与主矿区的距离增加,土壤样品中的稀土含量逐渐减少;在七种植物中,铁花的稀土含量最高,青蒿最低;对不同植物的整株稀土含量和各部位(根、茎、叶)稀土含量进行多元线性回归分析,叶(或花)的稀土含量在整珠植物中的占比最大。此外在不同季节,植物中的稀土含量基本保持不变,含量较高的稀土元素为Ce(0.0035%～0.020%)、La(0.0012%～0.011%)、Nd(0.0010%～0.0094%)和Pr(0.00036%～0.0046%),其中Ce最高。本研究提出:根据土壤样品中的稀土含量逐渐减少的特征,矿区周围土壤的稀土来源可能是矿石在采、选过程中的扩散造成的;根据植物富集稀土的能力,在矿山闭坑后,可种植富集稀土能力强的植物——铁花,进行矿山生物修复。 相似文献
19.
Effects of humic acid on heavy metal uptake by herbaceous plants in soils simultaneously contaminated by petroleum hydrocarbons 总被引：2，自引：0，他引：2
Soyoung Park Ki Seob Kim Daesok Kang Hansam Yoon Kijune Sung 《Environmental Earth Sciences》2013,68(8):2375-2384
The effects of humic acid (HA) on heavy metal uptake by herbaceous plants in soil simultaneously contaminated with heavy metals and petroleum hydrocarbons were investigated. The results showed that HA reduced readily soluble and exchangeable forms of heavy metals in the contaminated soil but increased their plant-available forms. Potential bioavailability and leachability factors became larger than 1 after adding HA to the soil, except for those of Ni, suggesting that more heavy metals could be potentially phytoavailable for plant uptake. Furthermore, HA increased the accumulation of Pb, Cu, Cd, and Ni in the shoots and roots of selected plants. The greatest increase in the accumulation of heavy metals was 264.7 % in the shoot of Festuca arundinacea, with the bioconcentration factor (BCF) increasing from 0.30 to 1.10. Humic acid also increased the BCFs of the roots of Brassica campestris for Ni and Pb. These results suggest that HA amendment could enhance plant uptake of heavy metals, while concurrently reducing heavy metal leachability and preventing subsurface contamination, even in soils simultaneously contaminated with petroleum hydrocarbons. 相似文献
20.
Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory 总被引：1，自引：0，他引：1
The present study deals with the characterization of effluent released from sponge iron industries and distribution of heavy
metals in soil and macrophytes near to effluent discharge channel. Apart from this, accumulation of heavy metals in nearby
soil and vegetation system irrigated with effluent-contaminated water is also the subject of this study. Physico-chemical
analysis of effluent reveals that the concentration of total suspended solids (TSS), total hardness (TH), iron (Fe2+), and oil and grease are greater than the IS (1981) norms for discharge of water into inland water body. The soil along the sides of the effluent channel also shows higher
concentration of heavy metals than the background soil. The enrichment of the heavy metals are in the order of Chromium (Cr) > Iron
(Fe) > Manganese (Mn) > Zinc (Zn) > Copper (Cu) > Cadmium (Cd). Macrophytes growing along the sides of the effluent channel
also show significant accumulation of heavy metals almost in the same order as accumulated in soil. Higher uptake of heavy
metals by these varieties reveals that these species can be used for future phytoremediation. The effluent as well as contaminated
water is extensively used for irrigation for growing vegetables like tomato (Lycopersicon esculatum) in the surrounding areas. Heavy metal accumulation in this agricultural soil are in the sequence of Cr > Fe > Mn > Zn > Cu > Cd.
More or less similar type of accumulation pattern are also found in tomato plants except Fe and Zn exceeding Cr and Mn. Transfer
Factor of heavy metals from soil to tomato plants (TFS) shows average value of <1, suggesting less uptake of heavy metals from soil. Among the plant parts studied, fruit shows
least accumulation. Although tomato plants show some phenotypic changes, the survival of tomato plants as well as least accumulation
of metals in fruit reveals their tolerance to heavy metals. Therefore it may be suggested that this plant can be grown successfully
in the heavy metal contaminated soil. Further research work on in situ toxicity test will be necessary in order to identify
the most resistive variety on this particular type of contaminated site. 相似文献