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1.
综合土壤重金属污染评价的单因子综合指数法、内梅罗综合指数法和地积累指数法的优点,以重金属含量平均值、毒性指标、变异系数和相关性四个因素建立层次分析结构图,通过构造成对比较矩阵,计算出了单因子综合指数法、内梅罗综合指数法和地积累指数法三种方法在土壤重金属污染评价中的综合权重,利用综合权重对土壤重金属的污染程度进行了排序和评估。 相似文献
2.
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
3.
以调查宿州市土壤的重金属污染状况数据为基础,按照有关标准和方法,对宿州市土壤重金属潜在生态风险进行了评价.结果表明:宿州市土壤中Cu,Zn,Cr,Cd,Hg,Pb,As 7种重金属含量都存在着一定幅度的变化,矿区土壤单因子污染指数Hg,Cr为重度污染、Cd,As轻度污染水平,耕地除Hg,Cr有部分超标外,其他重金属含量均达标;28.57%的土壤属于安全等级,32.86%的土壤属于警戒线,7.14%的土壤属于轻污染,2.86%的土壤属于中污染,28.57%的土壤属于重污染;67.14%的土壤属于低风险等级,5.71%的土壤属于中等风险等级,强风险等级土壤占15.72%,很强风险等级土壤占11.43%,而属于强风险、很强风险等级土壤都是矿区土壤,耕地均属于低风险等级;土壤中7种重金属对污染的贡献大小顺序为:Hg>Cr>Cd>As>Cu>Zn>Pb. 相似文献
4.
对香蕉园土壤与灌溉水添加Cd、Hg、As、Pb、cr、cu重金属元素,研究该重金元素对香蕉生长影响,以及香蕉叶片对该重金元素的富集能力。结果表明：当重金属的浓度累集到一定值时,会对香蕉的生长发育产生抑制作用,浓度太高会造成香蕉的生长停滞甚至死亡。随着土壤中Pb、Cd、As、Hg、cr、Cu重金属含量的增加,香蕉叶片中富集的重金属含量和富集系数表现为正相关的递增,香蕉叶片富集系数为Cr〉Cd〉Hg〉As〉Cu〉Pb,重金属的添加量与香蕉叶片体内含量的相关系数（r）分别为0．9630～0．9994、0．9128～0．9983。 相似文献
5.
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
6.
XU Dong-mei CHEN Bo LIU Wen-li LIU Guang-shen LIU Wei-ping 《浙江大学学报(A卷英文版)》2007,8(7):1157-1163
Comparative study on the activity and kinectic properties of acid phosphatase (ACPase) of three soils amended with Hg and Cu at constant temperature and humidity was carried out. The results indicated that the inhibition on ACPase of the three sample soils by Hg and Cu varied with the content of soil organic matter and pH, where, Soil 1 was the most seriously contami- nated due to its lowest content of organic matter and the lowest pH among three samples, Soil 2 took the second place, and Soil 3 was the least contaminated. Except Soil 3, the activity of soil ACPase tended to increase along with the contact time under the same type and the same concentration of heavy metal. In particular the Vmax values of ACPase in all three samples decreased with increasing Hg and Cu concentration, whereas the Km values were affected weakly. According to the change of Vmax and Km values, Cu and Hg had the same inhibition effect on soil ACPase. Both of them may be a type of compound of non-competitive and anti-competitive inhibition. Statistic analyses indicated that activities of soil ACPase and Vmax values could serve as bioindicator to partially denote the heavy metal Hg and Cu contamination degree. 相似文献
7.
针对尾矿库、垃圾填埋场底部土层受荷后的力学变形特性,以及考虑土体固结变形与重金属污染物运移转化模式、途径的不确定性与模糊性,通过分析国内外有关污染物运移模型,以及考虑土体固结变形与重金属污染物运移耦合模型的研究现状,指出现阶段研究中存在的不足,并提出考虑土体固结变形与重金属污染物运移转化相互耦合时应加强考虑传输介质间的非均相、非线性,建立综合考虑应力场、渗流场、浓度场、化学场,以及双电层引力场的重金属污染物运移转化模型,特别是在特殊土(如膨胀土、红黏土等)中建立土体固结变形与重金属污染物运移耦合模型以及计算方法,是今后研究工作的研究重点与发展方向。 相似文献
8.
绵阳市主要蔬菜基地土壤重金属污染特征与评价 总被引：1，自引：0，他引：1
采用地球化学元素背景值与绵阳浅层土壤元素背景值,按照地积累指数法与土壤重金属元素污染评价标准,对绵阳市主要蔬菜基地土壤重金属污染进行评价.结果表明：采用不同背景值得到相似的评价结果,研究区九岭镇蔬菜基地Zn为轻度污染,主要来自人为活动直接贡献;Cd为轻度污染,考虑为人为直接活动以外贡献;金峰镇蔬菜基地Cr、Cd为警戒水平,主要来自人为活动以外贡献;刘营镇蔬菜基地Zn、Cr为警戒水平,部分地区Cd为警戒-轻度污染,主要来自人为活动以外贡献. 相似文献
9.
研究浓缩型（正铵盐型）改良剂和有机型（有机酸型）改良剂在原位修复只受重金属Pb和Cd单独污染的土壤过程中的传质关系．对污染土柱浸泡,并通过分析其水浸取液中Pb、Cd的pH值变化、质量浓度变化来表征其迁移机制．研究结果表明：浓缩型改良剂和有机型改良剂都可以作为经济的重金属污染修复材料使用,但浓缩型改良剂比有机型改良剂修复效果好,修复效果稳定． 相似文献
10.
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
11.
INTRODUCTION Regulation, handling and bioremediation of hazardous materials require an assessment of the risk to some living species other than human being, or assessment of hazard to the entire ecosystem. As- sessment endpoints are values of the ecosystem that are to be protected and are identified early in the analysis. Such endpoints may include life cycle stages of a species and reproductive or growth patterns. Ecosystem risk assessment is at its dawn with this area of environment sci… 相似文献
12.
对漯河市蔬菜种植区土壤进行了重金属Cd、Pb、Hg、As、Cr、Cu、Zn、Ni含量的调查分析,并采用单项质量指数和环境要素综合质量指数相结合的方法对重金属环境质量状况进行了分析与评价。结果表明,漯河市3个主要露地蔬菜生产基地临颍、郾城和舞阳土壤重金属Cd、Hg、As、Pb、Cr、Cu、Zn和Ni的平均含量均低于"食用农产品产地环境质量评价标准"规定的限值。结合重金属的单项质量指数对三地菜地土壤的环境质量进行评价,舞阳有2个样品中的Cu和2个样品中的Ni质量指数大于0.7,环境质量等级为2级,属于尚清洁,处于警戒限;结合重金属的综合质量指数对三地菜地土壤的环境质量评定结果均为1级,土壤环境质量总体上属于清洁,适宜发展无公害蔬菜。 相似文献
13.
Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops 总被引：3，自引：0，他引：3
Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely： inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil （total or bioavailable concentration） that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include： soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary toxicity. 相似文献
14.
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
15.
对宿州市近郊农田土壤中4种重金属元素Cu、Pb、Zn和As的含量、空间分布及来源状况进行了分析,并采用综合指数法对其农田土壤重金属污染水平进行了评价。结果发现:宿州市近郊农田土壤中Cu、Pb、Zn的平均含量低于安徽省土壤背景值,As高于背景值;Pb和Zn的含量空间分布受交通污染源的影响,Cu与生活垃圾及废弃物的排放有关,As则来源于农药产品的使用;近郊农田土壤重金属为轻污染水平,以As污染最严重。 相似文献
16.
雷莹 《宁德师专学报(自然科学版)》2012,24(2):138-141
测试了宁德市茶园土壤中13种重金属的含量,并研究其分布特征,采用单项污染指数法和内梅罗综合指数法对宁德市茶园土壤重金属污染环境质量和土壤环境质量进行了评价.结果表明,在宁德市茶园土壤重金属污染单项评价中,平均值均未超标,但个别因子最大值超过1.0,为超标;在土壤重金属污染综合评价中属清洁,即茶园的土壤质量安全,但个别样点接近或略微超出警戒限,应引起必要重视. 相似文献
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18.
湛润生 《雁北师范学院学报》2013,(3):54-56
通过野外采样和实验室分析化验相结合的方法,分析了阳高县不同利用年限设施栽培土壤中汞、铅、锌、镍、钴含量的变化规律。结果表明,设施栽培土壤在利用4～7年时重金属元素含量最高。进一步依据温室蔬菜产地环境质量评价标准,采用单项污染指数法和尼梅罗综合污染指数法,对当地设施栽培土壤金属元素含量进行了污染评价。结果表明,阳高县设施栽培土壤未受到汞、铅、锌、镍污染,尚处于清洁状态。 相似文献
19.
Simulation models of heat and water transport have not been rigorously tested for the red soils of southern China.Based on the theory of nonisothermal water-heat coupled transfer, a simulation model, programmed in Visual Basic 6.0, was developed to predict the coupled transfer of water and heat in hilly red soil. A series of soil column experiments for soil water and heat transfer, including soil columns with closed and evaporating top ends, were used to test the simulation model. Results showed that in the closed columns, the temporal and spatial distribution of moisture and heat could be very well predicted by the model,while in the evaporating columns, the simulated soil water contents were somewhat different from the observed ones. In the heat flow equation by Taylor and Lary (1964), the effect of soil water evaporation on the heat flow is not involved, which may be the main reason for the differences between simulated and observed results. The predicted temperatures were not in agreement with the observed one with thermal conductivities calculated by de Vries and Wierenga equations, so that it is suggested that Kh, soil heat conductivity, be multiplied by 8.0 for the first 6.5 h and by 1.2 later on. Sensitivity analysis of soil water and heat coefficients showed that the saturated hydraulic conductivity, Ks, and the water diffusivity, D(θ), had great effects on soil water transport; the variation of soil porosity led to the difference of soil thermal properties, and accordingly changed temperature redistribution,which would affect water redistribution. 相似文献
20.
INTRODUCTION It is recognized that the transfer of soil moistureand heat occur simultaneously and are interrelated.Since the 1950s, many models have been developed,based on two nonisothermal water-heat coupledmodels by Philip and de Vries (1957) and Taylor andLary (1964), respectively. In China, some researcheson modeling coupled transfer of soil moisture andheat have also been conducted on the arid soils innorthern China (Kang et al., 1993; Guo and Li, 1997;Hu et al., 1992; … 相似文献