红薯对Pb、Cd的吸收累积特征及根际土壤Pb、Cd形态分布研究

为了解土壤在Pb、Cd单一以及复合污染条件下红薯对Pb、Cd的吸收和积累规律,通过盆栽试验对红薯地上部和地下部的生物量和重金属含量进行测定,分析了单一及复合污染土壤中重金属Pb、Cd形态分布特点。结果表明,相对于对照,较低浓度的Pb、Cd能显著促进红薯的生长（P〈0.05）,Pb超过50mg.kg-1、Cd超过3mg.kg-1时,红薯生长受到显著抑制（P〈0.05）,Cd是影响红薯生长的主要因素;随着试验处理浓度的升高,红薯体内重金属含量也随之升高,二者之间存在极显著的相关性（P〈0.01）,Pb、Cd共存对红薯吸收累积Pb、Cd具有明显的交互作用,Pb促进Cd向地上部转移,Cd促进Pb在地下部积累。根际土壤中Pb、Cd以可交换态与碳酸盐结合态为主,二者均占总量的55以上,在复合污染条件下,Pb浓度为50mg.kg-1时其活性系数显著高于其他Pb处理（P〈0.05）,并在很大程度上促进有效态Cd含量的增加。     

再生水灌溉冬小麦的铅和镉累积分布研究

再生水灌溉对作物重金属含量的影响,是再生水能否安全利用的重要基础问题。通过冬小麦的盆栽试验,研究了再生水灌溉对土壤和冬小麦植株铅、镉含量的影响。结果表明,再生水灌溉对土壤铅、镉含量没有明显的影响,而混灌和轮灌较再生水纯灌可以降低土壤铅含量,但对土壤镉含量没有明显的减低作用。再生水灌溉处理小麦各器官的镉含量分布是根〉叶〉茎〉籽粒,铅含量分布是叶〉根〉茎〉籽粒,叶片铅含量较其他器官高可能与大气铅污染有关。再生水灌溉后,小麦各器官镉含量较清水对照有一定的提高,但铅、镉含量和对照相比差异不显著。应用再生水灌溉,小麦籽粒中铅、镉含量均符合国家食用安全标准,但镉含量较清水灌溉有升高现象,在生产应用中要有所注意。     

Cd, Ni, Pb, and Zn Concentrations in Forest Vegetation and Soils in Maine

Bioaccumulation of trace metals in plant tissues can present a health risk to wildlife, and potentially to humans. The Passamaquoddy tribe in Maine was concerned about health risks of cadmium (Cd) because of a health advisory for moose liver and kidney consumption due to high Cd levels. This study found relatively low to moderate concentrations of Cd, nickel (Ni), lead (Pb), and zinc (Zn) concentrations in four common terrestrial moose browse species, associated forest soils, and two species of aquatic vegetation on Passamaquoddy tribal land in eastern Maine. Terrestrial plant tissue concentrations ranged from 0.1 to 1.97, 0.65 to 7.08, 0.29 to 2.0, and 42 to 431 mg kg^?1 for Cd, Ni, Pb and Zn, respectively. Deciduous species, particularly aspen and birch, may be a more significant source of Cd and Zn to wildlife compared to coniferous or aquatic species. Aquatic plant tissue concentrations ranged from 0.11 to 0.14, 0.46 to 1.01, 0.8 to 0.9, and 22 to 41 mg kg^?1 for Cd, Ni, Pb and Zn, respectively. Total O horizon concentration means for coniferous and deciduous were 0.50 and 1.00, 4.27 and 4.11, 55 and 21, and 55 and 167 mg kg^?1 for Cd, Ni, Pb and Zn, respectively. The study provides baseline vegetation and soil trace metal concentrations for a remote region in Maine impacted by non-point sources.     

不同品种烟草生长和镉及营养元素吸收对镉胁迫响应的差异

通过盆栽试验研究了两个品种烟草Xanthi和贵烟11号生长、镉的吸收和运转及营养元素吸收对镉胁迫的反应.结果表明,Xanthi的生长量在3 mg/kg Cd处理时增加.10 mg/kg Cd处理时降低,贵烟11号根及地上部的生长则随土壤镉浓度的提高而降低,表明Xanthi较贵烟11号对镉有更强的忍耐能力.提高土壤镉水平,烟草根和地上部镉含量增加,镉的转运系数下降,下降幅度为Xanthi＞贵烟11号.两个品种烟草镉的向上转运速率,Xanthi表现为先上升后下降的过程,贵烟11号则持续上升.表明Xanthi根部阻止镉向地上部运输的能力较贵烟11号强.镉对两个品种烟草N,K,Zn,Mn的吸收有促进作用.对Fe,Mg的吸收有抑制作用.对Xanthi的P吸收有促进作用、Ca吸收有抑制作用,对贵烟11号的P含量影响不明显,却提高贵烟11号的Ca含量.     

Pb、Cd复合胁迫下4种植物抗氧化防御差异性研究

为了解植物在Pb、Cd复合胁迫下抗氧化系统的响应, 研究了重金属超富集植物龙葵、印度芥菜和非重金属超富集植物玉米和萝卜在Pb、Cd复合胁迫下抗氧化系统的变化。研究结果显示: Pb、Cd复合胁迫下超富集植物印度芥菜和龙葵的叶生物量显著减少, 根和茎生物量在低浓度处理下减少不明显; 非超富集植物萝卜和玉米的生物量随重金属浓度升高显著降低。超富集植物的SOD活性随重金属浓度升高逐渐升高; 4种植物POD活性随重金属浓度变化规律各不相同, 非超富集植物玉米和萝卜POD活性总体上随重金属浓度增加而提高; 超富集植物叶片MDA含量随重金属浓度升高逐渐升高; 印度芥菜和萝卜的总GSH含量显著高于其他两种植物。超富集植物的SOD、MDA、TAST、总GSH和PC与土壤重金属毒性系数呈显著相关; 非超富集植物玉米的POD和总GSH与重金属毒性系数呈显著相关, 而萝卜的TAST和PC与重金属毒性系数呈显著相关性。不同植物的解毒机制并不相同, 因而进一步了解超富集植物的相关酶基因调控对阐明解毒机制尤为重要。     

右江河谷地区土壤重金属Cd、Pb含量的空间分布特征

按照10 km×3 km的网格,用5点取样法在广西百色右江河谷地区地表浅层采集71个土壤样品,测定重金属元素Cd和Pb的含量,分析土壤样品Cd和Pb含量间、Cd和Pb含量与样品采集地高程之间的相关性,并用Surfer16软件做出它们的空间分布图,研究了土壤Cd和Pb含量在该地区的空间分布规律。结果表明:右江河谷地区地表浅层土壤Cd和Pb平均含量分别为0.55、49.4 mg kg^-1,和百色地区全区土壤Cd和Pb含量平均值相比,表现出明显的富集趋势;Cd和Pb含量的变异系数分别为45%和52%,属于高度变异范围;Cd和Pb两元素含量之间的相关系数为0.760(n=69),达极显著水平,Pb含量与样品采集地高程之间也有一定的相关性,显示出相对高的地形对Pb的空间分布具有阻隔作用;土壤Cd和Pb含量的空间分布具有较强的相似性,河谷地区东部铝土矿区附近含量最高,西部的百色城区次之,说明当地的矿山开采和城市居民活动对土壤Cd、Pb元素空间分布均有影响;河谷北缘土壤Cd和Pb含量略高于河谷南缘,可能是风的搬运作用结果;两元素比较,土壤Cd含量受河谷内工业企业的影响大于土壤P...     

Distribution of Zn, Cd, Pb and Cu Metals in Groundwater of the Guadiamar River Basin

Traditionally, the Guadiamar River Basin (Seville, SouthwestSpain) has received pollution from two different sources. Inits upper course, from a pyrite exploitation and, in itslower reaches, from untreated urban and industrial wastes aswell as wastes from intensive agricultural activity. In 1998,the accidental release in the river of about 6 million m³ of acid water and sludge from mine tailings contributedto worsen the pollution of an already contaminated area. Themain polluting agents of the spill were heavy metals. Itaffected a large number of wells either directly or as a consequence of infiltration from polluted soils. Assessment of the pollution by total metal determination does not revealthe true environmental impact of the spill and speciation studies showing the distribution of the main pollutants are required. There is a direct association between the physicochemical speciation of an element and its bioavailability, toxicity and mobility. This article describesa distribution study of the metals Zn, Cd, Pb and Cu by speciation analysis of groundwater in six wells of the GuadiamarRiver Basin; the samples were taken several weeks after the spill. The speciation analysis resulted in the definition ofthree species categories: a) labile metal (H⁺ exchangeable),b) metal strongly associated to dissolved organic matter and c) metal associated with suspended material. Analysis was carried out by anodic stripping voltammetry (ASV). Metal speciation ingroundwater of the Guadiamar River Basin allows a differentiationbetween: on the one hand, metals from the mining spill, andon the other hand a less recent pollution from accumulatedinfiltration of either mining or agricultural origin, the last one due to an abuse of phytosanitary products.     

铅-锌-镉复合污染物在土壤-芥菜/油菜系统中的迁移及交互作用

了解重金属复合污染物在土壤-植物系统中的迁移分配情况对污染土壤的安全利用、土壤环境质量标准的修订以及重金属污染土壤的植物修复具有重要意义。通过盆栽试验,以芥菜和油菜为例,研究了铅-锌-镉复合污染物在土壤-植物系统中的迁移分配情况。结果表明:与对照相比,复合污染条件下,芥菜和油菜体内重金属含量显著提高,且Cd含量的提高程度要远远高于Pb和Zn;芥菜和油菜对Cd的吸收达到了100 m g/kg以上,表现出超富集植物的吸收水平。重金属的富集系数大小依次为Cd>Zn>Pb,地下部富集系数要高于地上部,转运系数大小为Cd≈Zn>Pb。Pb、Zn、Cd的富集系数均随各自元素在土壤中含量增大而减小,而且表现为低含量时显著减小,高含量时缓慢减小;重金属在土壤-植物系统的迁移分配深受共存元素的影响,且在不同元素之间和不同浓度范围内表现出不同的特点。Pb、Zn、Cd在芥菜和油菜体中积累量,均与其各自在土壤中的含量成正相关;Zn和Cd对Pb的吸收积累以及Pb对Zn的吸收积累具有明显的抑制作用;Zn-Cd对Zn的吸收积累具有正的交互作用,而对Cd的吸收积累具有负的交互作用。     

Distribution of As, Cd, Pb, and Zn in redox features of mine-waste impacted wetland soils

Purpose

Wetland soils of the Coeur d??Alene (CdA) River Basin of northern Idaho, USA are contaminated with toxic elements released during mining activities. In this paper, we report results from a multi-scale investigation of total As, Cd, Pb, and Zn distributions along a transect of these contaminated soils.

Materials and methods

Four sites along an 80-m transect were established at the Black Rock Slough wetland in CdA River Basin. The elevation difference between the upslope and lowland site was 1.1?m. Soils were sampled from three depths, down to 45?cm. Redoximorphic features were isolated from the soils and categorized into five types of cemented particles, and Fe-enriched and depleted soil masses. Soils and isolated soil separates were analyzed for total elemental concentration.

Results and discussion

Within soil profiles, contaminants are enriched in surface horizons as compared to the original depositional profiles. Enrichment was more dramatic in the upland sites than the lowland sites. Fe-enriched masses that ranged in size from a few millimeters to several centimeters were also enriched in As, Pb, and Zn. At the smallest scale investigated, five different soil aggregate types ranging in size from 1 to 2?mm in diameter had distinct contaminant associations: Fe-cemented aggregates were elevated in As and Zn; Mn-cemented aggregates had more than five times as much Pb as the bulk soil; root channels were elevated in As; and charcoal particles were elevated in all contaminants, particularly Pb and Cd.

Conclusions

Results show that in wetland soils pedogenic processes differentially distribute contaminants amongst the redoximorphic features. The distribution is affected by landscape position and water table influence. At the pedon scale, there is an enrichment of As, Cd, Pb, and Zn in surface horizons, suggesting that upward flux of contaminants is occurring. This contaminant redistribution should be considered in design of management and remediation strategies.     

铅-锌-镉复合污染物在土壤-芥菜/油菜系统中的迁移及交互作用

了解重金属复合污染物在土壤-植物系统中的迁移分配情况对污染土壤的安全利用、土壤环境质量标准的修订以及重金属污染土壤的植物修复具有重要意义。通过盆栽试验,以芥菜和油菜为例,研究了铅-锌-镉复合污染物在土壤-植物系统中的迁移分配情况。结果表明：与对照相比,复合污染条件下,芥菜和油菜体内重金属含量显著提高,且Cd含量的提高程度要远远高于Pb和Zn;芥菜和油菜对Cd的吸收达到了100 m g/kg以上,表现出超富集植物的吸收水平。重金属的富集系数大小依次为Cd〉Zn〉Pb,地下部富集系数要高于地上部,转运系数大小为Cd≈Zn〉Pb。Pb、Zn、Cd的富集系数均随各自元素在土壤中含量增大而减小,而且表现为低含量时显著减小,高含量时缓慢减小;重金属在土壤-植物系统的迁移分配深受共存元素的影响,且在不同元素之间和不同浓度范围内表现出不同的特点。Pb、Zn、Cd在芥菜和油菜体中积累量,均与其各自在土壤中的含量成正相关;Zn和Cd对Pb的吸收积累以及Pb对Zn的吸收积累具有明显的抑制作用;Zn-Cd对Zn的吸收积累具有正的交互作用,而对Cd的吸收积累具有负的交互作用。     

Runoff and soil loss under different tillage methods on Stagnic Luvisols in central Croatia

Owing to humid climate and unfavourable relief, the problem of extensive soil erosion in central Croatia is of prime importance. The main objective of this research was to determine how soil erosion is influenced by deep (30 cm) soil tillage practised for deep-rooted row crops in comparison with other tillage methods, on Stagnic Luvisols. Soil loss quantity was recorded during the 4-year investigation cycle (1994–1998), under common field crops grown under six tillage methods. Appreciably higher rates of soil erosion were recorded in low-density row spring crops than in high-density winter crops under the same tillage methods. The time immediately following the sowing of spring crops was the most critical period, i.e. the period when highest soil loss occurs. The results showed that erosion processes cannot be completely stopped; however, they can be reduced to an acceptable level by an appropriate tillage method. Efficient soil conservation on Stagnic Luvisols was achieved by no-tillage and all across the slope tillage methods.     

施肥对铅镉污染土壤上芥菜铅镉含量及生理的影响

盆栽试验研究了不同化学肥料组合处理对铅镉污染土壤上芥菜(Brassica juncea)Pb、Cd含量及其生理特性的影响。结果表明, 与对照相比, 各肥料处理在显著提高芥菜生物量的基础上, 显著降低了芥菜地上部Cd含量(P<0.05), 其中碳酸氢铵+磷酸二氢铵+硫酸钾处理的效果最佳, 芥菜Cd含量仅为对照的41.0%; 施肥处理提高了芥菜地上部Pb含量, 但Pb没有健康风险; 施肥提高了叶菜的叶绿素含量, 但丙二醛、脯氨酸、细胞质膜透性与芥菜地上部Pb、Cd含量无显著相关性。重金属污染土壤施肥处理是一种值得推广的降低叶菜有害重金属含量的有效技术。     

黄土高原林草地覆盖土壤水量平衡研究进展

黄土高原地处干旱半干旱区,水是地区生态环境改善的主要限制因子,严重阻碍了当地的植被恢复和生态重建.黄土高原林草地覆盖土壤蓄水量既有收入,又有支出,始终处于一种动态平衡但相对亏缺的状态.以黄土高原降雨时空变化、林草地土壤水分入渗、土壤水分蒸发蒸腾、土壤干层的形成以及水量平衡模型模拟等几个关键因素为切人点进行详细阐述,对其国内外研究进展进行回顾.提出关于黄土高原土壤水量平衡的研究,应在成熟林草地水源涵养功能及林草地水文生态过程的尺度扩展方面加大力度.     

Toxic Metals (As, Cd, Ni and Pb) and PM2.5 in Air Concentration of a Model Ceramic Cluster

The relationship between ambient concentrations of fine particulate matter and detrimental health effects remains a highly controversial issue. Increased incidence of mortality and morbidity due to cardiopulmonary complications has been associated with elevated levels of urban air particles with an aerodynamic of <2.5 ??m (PM2.5). The main aim of this paper was to present the assessment of the temporal and spatial variations of the PM2.5 fraction and its contents in arsenic, cadmium, nickel and lead in order to identify possible emission sources of these pollutants. Daily ambient aerosol samples (PM2.5) were taken in the province of Castellón from 2008 to 2009. Particle concentration levels were determined by gravimetry, and the As, Cd, Ni and Pb levels in the samples were determined by inductively coupled plasma mass spectroscopy. The season variation of these pollutants differs according to the emission source and the factors involved in dispersion. In the weekly trend, there were no significant differences in levels among sampling sites in relation to the day activity (working vs. non-working) due to chemical pollutants that are found in fine particulate fractions residing in the atmosphere longer than coarse particles, resulting in a more homogeneous concentration of pollutants over time. In order to identify similar behaviour between chemical pollutants and PM2.5, an assessment of the correlation between them was carried out. This behaviour study shows whether the source of contaminants is the same. A statistical analysis of the levels of PM2.5 and the presence of As, Cd, Ni and Pb in the different sampling sites was performed in order to evaluate the influence of the sampling point on the concentrations of these pollutants.     

东北农田黑土中Cd、Pb、As含量空间分异特征分析

采用点面结合方法,研究了东北区农田黑土中Cd、Pb、As含量的空间分异特征。结果表明,三种元素含量的变异系数为Cd>Pb>As。Cd、Pb的平均含量高于其背景值;其中Cd有45个样品超过了国家二级标准限值。Cd、Pb、As含量由南至北未表现出明显的分布规律。对煤矿区周围农田土壤的调查发现,煤矿是其周围农田土壤的主要污染源。采用最优内插法得到了长春市市郊农田黑土中Cd、Pb、As含量的空间分布图,结果表明人为活动显著改变了局部地区Cd、Pb、As的含量,污染源主要为汽车尾气和固体废弃物的堆积。对三种元素垂直分布进行了分析,剖面土层Cd、Pb、As主要来自于表面污染源,向下迁移作用还不很强烈。     

红河干热河谷林草地红壤中优先流的形态分布特征

[目的]在红河干热河谷地区开展优先流形态分布特征及与红壤特性关系的研究,为区域水资源管理和防治水土流失等工作提供理论依据.[方法]以干热河谷地区典型植被林地和荒草地为研究对象,采用野外染色示踪法并结合图像处理技术研究优先流的形态分布特征及对红壤特性响应.[结果]①林草地上层剖面平均染色面积分别为87.20％和91.97...     

搞好退耕还林需着重解决的几个问题

通过对山西省实施退耕还林政策两年来各种情况的调查,考虑全省社会经济发展的综合因素,提出搞好退耕还林需着重解决的几个问题是:吃饭问题,烧柴问题,花钱问题,林权证的发放问题,生态林转移支付与永续利用问题,污染防治问题,替代产业扶持问题,生态移民与小城镇建设等问题。     

洛阳市城区雪松松针铅含量空间分布

通过对洛阳市城区居民区、商业区、工业区、风景区4种功能类型区中的11个采样点中的10～15年生雪松松针（SA）、地面落针（SB）和20～30年生雪松松针（SC）、地面落针（SD）中重金属Pb含量的测定,分析了洛阳市城区大气中Pb污染现状。结果表明：洛阳市城区雪松松针Pb含量平均为1.606mg/kg,属重金属轻度污染;居民区、商业区、工业区、风景区雪松松针Pb含量差异显著,表现为工业区〉居民区〉商业区〉风景区;松针中Pb含量主要受冶炼、工业废气、汽车尾气排放等人为活动因素影响。雪松松针Pb含量分异性可以客观反映城市不同区域内大气Pb污染程度,这为城市环境保护研究提供了新方法,值得推广使用。     

黑土中镉、铅的化学形态分布及其植物效应研究

采用盆栽试验和连续形态分析方法研究了黑土中Cd、Pb的化学形态特征及其与油菜生长及吸收Cd、Pb量的关系。结果表明,随土壤Cd、Pb含量的增加,Cd交换态含量增幅较大,而Pb碳酸盐结合态、铁锰氧化物结合态含量增幅较大,交换态Pb含量相对较低。随土壤Cd、Pb含量的增加,油菜地上、地下部分的Cd、Pb含量呈递增趋势,但增加速度随土壤Cd、Pb含量的升高而递减。地下部分Cd、Pb含量远高于地上部分的含量。与Pb相比,Cd向地上部分的迁移率较大,其毒害作用更强。土壤中Cd、Pb各形态含量与油菜地下、地上部分吸收的Cd、Pb量均显著相关,碳酸盐结合态对油菜吸收Cd、Pb的贡献最大。     

不同肥料长期施用下稻田镉、铅、铜、锌元素总量及有效态的变化

以中国科学院桃源农业生态实验站的长期田间定位试验为基础,研究了16年长期定量施肥对土壤Cd、Pb、Cu和Zn积累及其有效性的影响。结果表明:单施化肥可使土壤Cd含量降低、Pb含量增加,对Cu和Zn的积累无显著影响,水稻收获时的移出效应可能是Cd含量降低的主要原因;与单施化肥相比,有机物料循环可提高土壤Cd和Pb的积累,但对Cu和Zn的积累无显著影响。试验期内单施化肥对土壤Cd、Pb、Cu和Zn的有效性无显著影响;有机物料循环可显著提高Cd和Zn的有效性,这与有机物料循环引起的土壤有机质含量增加和pH降低有关。