贵阳市大气降水中的重金属特征

采集了贵阳市2003年9月—2004年10月的72场降雨样品,用ICP-MS测定了雨水溶解态的Pb、Zn、Cu、Fe、Mn、Al、Sr等重金属离子,阐述了贵阳市降雨的重金属含量特征,并分析了重金属的来源及变化规律。结果表明,贵阳市雨水重金属含量高,Fe、Mn、Cu、Pb、Zn均高于地表水,雨水的重金属含量受人为因素影响明显,燃煤及汽车尾气是雨水重金属的主要来源,为评价贵阳市大气中的重金属污染提供了有力的证据。     

台风暴雨型浅层滑坡失稳机理研究

针对台风暴雨耦合作用下浅层滑坡的失稳机理进行研究。在总结福建台风暴雨型滑坡灾害特征的基础上,提出风荷载对斜坡变形失稳的影响机理是通过植被造成坡体开裂,从而影响坡体的入渗规律。应用GeoStudio软件计算台风暴雨入渗条件下裂隙坡体中暂态非饱和渗流场的变化,以及对斜坡稳定性的影响。计算结果表明:裂隙坡体由于在裂隙处形成集中入渗点,雨水的入渗速度大于无裂隙的坡体,坡体达到饱和状态所需要的时间大为缩短。裂隙深度、间距对滑坡稳定系数的影响较大,裂隙深度越大、间距越小,在相同的降雨条件下滑坡的稳定系数越小,滑坡失稳需要的降雨时长越短。裂隙宽度对滑坡稳定性的影响相对较小。      

Sulphide-mining impacts in the physical environment: Sierra de Cartagena–La Unión (SE Spain) case study

The environmental impact and potential-risk assessment of an abandoned sulphide-mining site in a semiarid climate is presented here, by the study case of Sierra de Cartagena–La Unión (SE Spain), a 2,500-year-old mining district extending over an area of 100 km². The regional map illustrates the existence of 12 open-pits, 1,902 mining wells, 2,351 waste deposits, including 89 tailing dams and waste rock derived from mining processes. Mine wastes occupy an area of 9 km² and have an approximate volume of 200 Mm³. Mineralogical, physical and chemical data distinguish nine different types of mine and metallurgical waste. According to the concentration of sulphate and heavy metals in sediment, soil, rainwater, surface water and groundwater samples, it is possible to conclude that the impact of mine activities occurs not only in the immediate mining area (100 km²), but also in the surrounding areas (an affected area of 1,000 km² approximately). The hydrochemical data show that groundwater, runoff water and some rainwater samples exceed Spanish and European water quality guideline values for water supply. The main geochemical process recognised is sulphide-mineral oxidation and later-generated sulphate dissolution by groundwater and runoff. Runoff and wind are the major mechanisms of metals and sulphate transport in the study area and adjacent zones.     

吉林省部分河流与湖泊表层沉积物中重金属的分布规律

河流的水化学组成具有多样性和易变性,而湖泊水则因其交换缓慢,即使与河流所在地区的气候条件和地球化学条件相似,其化学组成也明显区别于河流,沉积物中重金属的分布也不同.利用形态分析、相关分析和地累积指数法研究了吉林省境内部分河流、湖泊沉积物重金属分布规律.研究结果表明,伊通河和南湖重金属元素生物可利用态含量都很高,存在较大的、潜在的生态危害,Pb、Cu在有机物态中表现出明显的赋存趋势;河流沉积物中Cu、Pb、Zn与pH值显著相关,但湖泊中却相关性不显著.河流沉积物受重金属污染较严重,污染程度最高达到4级,属强污染,湖泊污染程度较轻.     

沈阳细河沿岸土壤中重金属垂直分布特征与形态分析

研究了沈阳细河沿岸翟家、彰驿和黄腊坨地区13个土壤剖面样品中重金属的垂直分布特征,对土壤环境危害较大的3种重金属元素Cd、Hg、As进行了重点分析。采用改进的Tessier连续萃取法研究了5个表层土壤中7种重金属元素的形态分布。研究表明土壤重金属元素形态分布具有以下特点:As、Cu、Cr、Zn和Pb主要以残渣态存在;Cd主要以离子交换态存在,残渣态所占的比例较低,表明表层土壤中Cd的活动性较强,容易迁移进入生态食物链。大部分样品中Hg以残渣态为主。除Cd外,土壤中其余6种重金属的可交换态含量都比较低。7种重金属的潜在迁移能力顺序为:CdHgPbZnCrCuAs。     

Floodplain sediments of the 2002 catastrophic flood at the Vltava (Moldau) River and its tributaries: mineralogy,chemical composition,and post-sedimentary evolution

Fine-grained floodplain sediments of the catastrophic 2002 flood deposited along the lower reaches of the Berounka and Vltava Rivers, Czech Republic, were not highly contaminated with heavy metals and other toxic elements. This is due to the dominantly mineral character of the sediments (C_tot in the range 3.97–5.01%, relatively low content of clay minerals), and due to the very high degree of contamination dilution by eroded pre-industrial non-contaminated floodplain sediments. Despite this high degree of dilution, the influence of the small Litavka River, draining the historical Pb–Zn–Ag Příbram ore region, is well visible. The Litavka River is one of important sources of Pb and Zn contamination in the whole Berounka–Vltava–Labe river system. The 2002 flood sediments deposited in the floodplain of the Berounka and Vltava Rivers show poor vertical chemical zoning, except for some components enriched in the uppermost layer by precipitation from evaporated pore-water contained in the mud, i.e. secondary carbonate. The content of C_carb of the sediments (0.05–0.15%) is partly represented by this secondary carbonate, which is later leached by rainwater, and partly by fragments of river mollusk shells. A majority of the heavy metals contained in sediments can be readily leached by diluted acids, and to a much smaller degree by rainwater.     

Chemical Forms of Heavy Metals in Carbonate—Derived Laterite and Enrichment of Its Iron Oxide Minerals

In this paper the seven-step continuous extracting method was employed in the study of chemical forms of the six heavy metals Co,Zn,Pb,Cu,Cr and Mn,The result shows that the etals in the laterite are present in the chemical form of crystalline iron oxides and residues,and they are transformed towared organic and exchangeable forms in the surface soil.Linear regression analysis indicates that the above heavy metals have a positive correlation with the crystalline iron oxide minerals.The crystalline iron oxide minerals have a very important role to play in the enrichment of heavy metals,especially the solid components in the laterite.     

用微生物对单一碳源利用方法探讨重金属在城市土壤中积累的环境效应

Biolog研究表明，英国阿伯丁市城市土壤的微生物群落结构显著有别于农村土壤，并使微生物对碳源的消耗量增加，消耗速度加快。城市土壤中不仅重金属Cu,Pb,Zn,Ni的含量明显高于农村土壤，而且其化学形态的主成分分析表明，有效态Pb,Zn,Cu及有机态Ni和Cu是导致城市土壤区分于农村土壤的主要因子。相关性分析表明，Biolog的这种变化规律与重金属的上述化学形态密切相关；典型变量分析表明，重金属对城市土壤微生物群落结果的这种损伤具有长期性效应及不可恢复性。     

福建龙海土壤重金属含量特征及影响因素研究

为有效预防土壤重金属生态风险,以福建龙海市表层土壤为研究对象,应用经典统计分析、随机森林等方法,研究重金属元素含量特征及其影响因素。结果表明：(1)第四纪冲洪(海)积成因水稻土中多数重金属元素含量较高;(2)燕山期中酸性岩风化形成的残坡积红壤中重金属元素活动态含量较高;(3)As、Cu、Ni形态含量与全量相关性较好,而Cd、Cr、Hg的多数形态含量与全量相关性较差;(4)除元素全量外,土壤有机质对弱有机结合态重金属(不包括Ni、Pb元素)以及离子交换态、碳酸盐结合态Cd、Zn有重要影响,阳离子交换量对各形态Ni,(Fe×Al)/Si对各形态Cu具有重要影响,而土壤成因、土壤类型对重金属形态组成的影响较小。研究表明土壤重金属形态组成及其富集区与其全量不尽一致,土壤重金属生态风险评价应考虑土壤重金属形态分布特征。     

Rainfall infiltration: infinite slope model for landslides triggering by rainstorm

Shallow slope failure due to heavy rainfall during rainstorm and typhoon is common in mountain areas. Among the models used for analyzing the slope stability, the rainwater infiltration model integrated with slope stability model can be an effective way to evaluate the stability of slopes during rainstorm. This paper will propose an integrated Green–Ampt infiltration model and infinite slope stability model for the analysis of shallow type slope failure. To verify the suitability of the proposed model, seven landslide cases occurred in Italy and Hong Kong are adopted in this paper. The results indicate that the proposed model can be used to distinguish failed and not-yet failed slopes. In addition, the proposed model can be used as the first approximation for estimating the occurrence time of a rainfall-induced shallow landslide and its depth of sliding.     

江汉平原大气污染源分析

通过选择不同的环境功能区布置大气干湿沉降样点,分析重金属污染元素和有机氯农药的颗粒态与溶解态指标,计算季沉降通量和年沉降总量,了解其随季节变化的规律,分析比较不同地貌条件、不同城市及不同污染源区对其沉降的源贡献。结果表明:大气对江汉平原重金属的输入途径以降水为主;重金属元素颗粒物在平原区的沉降通量略高于岗丘地区;武汉市高于其他城市;工业污染源区明显高于一般农田区;三类污染源区相比,颗粒态为烟尘>化工尘>交通尘,溶解态为化工尘>交通尘>烟尘(个别元素除外),且大气降水中的营养元素N、K、Fe在化工工业区较为富集,而P的沉降在烟尘和化工工业区则受到一定程度的抑制。两种主要有机氯农药不同异构体间的组分关系表明本区环境中近期仍有林丹输入。     

基于高光谱技术的黑土地微量金属元素探测方法及地学意义

在土壤中重金属含量较低的情况下,重金属的高光谱特征响应非常微弱,不易构建精确的高光谱直接反演模型.为了解决上述问题,依据土壤化学变量间的理化性质,将重金属富集特征转移到与之相关的化学主量元素上,使重金属微弱的信息得以间接定量反演.文中以海伦市黑土土壤为研究对象,通过主成分分析、 聚类分析确定了主量元素氧化铁(Fe2O3...     

Speciation and mobility of heavy metals in mud in coastal reclamation areas in Shenzhen,China

Coastal reclamation has been carried out along the coastal areas near Shenzhen, China in a large scale since 1980s by dumping fill materials over the marine mud at the sea bottom. Usually the area to be reclaimed is drained first and some of the mud is air-dried for a few weeks before it is buried by fill. After reclamation, the terrestrial groundwater, which is relatively acidic and with high dissolved oxygen, gradually displaces the seawater, which is alkaline with high salinity. The changes in the burial conditions of mud and the properties of the pore water in the mud may induce the release of some heavy metals into the mud. Field survey confirms that the pH and salinity of the groundwater in the reclamation site are much lower than the seawater. Chemical analyses of mud and groundwater samples collected from the reclamation sites reclaimed in different years indicate that most of the heavy metals in the mud decrease gradually with time, but the heavy metals in the groundwater are increased. The release of heavy metals into pore water due to reactivation of heavy metals in the mud is of environmental concern. To understand why some of the heavy metals can be released from the mud more easily than others, a sequential extraction method was used to study the operationally determined chemical forms of five heavy metals (Cu, Ni, Pb, Zn, and Cd) in the mud samples. Heavy metals can be presented in five chemical forms: exchangeable, carbonate, Fe–Mn oxide, organic, and residual. Ni and Pb were mainly associated with the Fe–Mn oxide fraction and carbonate fraction; Zn was mainly associated with organic fraction and Fe–Mn oxide fraction, while Cu and Cd were associated with organic fraction and carbonate fraction, respectively. If the residual fraction can be considered as an inert phase of the metal that cannot be mobilized, it is the other four forms of heavy metal that cause the noticeable changes in the concentration of heavy metals in the mud. On the basis of the speciation of heavy metals, the mobility of metals have the following order: Pb (36.63%) > Cu (31.11%) > Zn (20.49%) > Ni (18.37%) > Cd (13.46%). The measured metal mobility fits reasonably well with the degree of concentration reduction of the metals with time of burial observed in the reclamation site.     

广西红水河中下游马山地区地下水重金属含量及分布特征

为了解红水河中下游马山地区地下水重金属含量及分布特征,以西南岩溶地下水污染调查评价中广西红水河中下游马山地区地下水数据为基础,对该地区27件样品的重金属含量特征、重金属间相关关系、重金属与其它化学组分的相关性以及地下水重金属分布特征进行了研究。结果表明:研究区地下水中重金属含量整体偏低,平均质量浓度顺序为Fe＞(Al)＞Zn＞Mn＞Pb＞Se＞As＞Cd,重金属平均质量浓度均小于中国生活饮用水标准值,且绝大部分重金属含量远远低于该标准值。Mn与Fe、As、Al存在显著或极显著的正相关关系,Zn与Pb、Cd存在明显的相关性,Se与其它７种重金属的相关性均不明显,可能是由于Se与其它重金属的来源差异较大所致。地下水的酸碱性对重金属的富集影响较小,但地下水中主化学成分HCO3-和Ca2+对重金属的富集有较大影响,TDS对绝大部分重金属的影响较小,对As和Cd具有一定的影响。地下水中Mn、Zn、As、Pb、Cd、Se、Al、Fe质量浓度在空间上表现出一定的地区分布特点,整体上重金属高浓度点主要集中在马山县城周围以及古寨、乔利街乡镇周围。      

干旱区绿洲土壤共存重金属元素形态变化及生物有效性实验分析——以Cd、Zn、Ni元素为例

采用盆栽试验,初步研究了干旱区绿洲土壤—胡萝卜系统中镉、锌、镍3种重金属的形态变化特征及其生物有效性问题。结果表明:供试绿洲土壤原状土中,Cd、Zn、Ni均以稳定的残渣态形式存在,而处理土壤中重金属被钝化的量有限,Cd的存在形式主要以碳酸盐态为主,Zn、Ni则主要以铁锰氧化态为主;3种元素的活性大小依次为Cd>Ni>Zn。根据回归分析,元素Zn对胡萝卜块茎和茎叶吸收Zn量贡献最大的分别是Zn的碳酸盐结合态和铁锰氧化态;元素Ni对胡萝卜各部位吸收贡献最大的均为Ni的铁锰氧化态。     

城市污泥接种堆置处理对重金属的形态及其生物有效性的影响

污泥堆肥化后的土地利用是污泥处理处置的重要方法之一。经过对荆马河底泥接种堆置处理,揭示出污泥中重金属的形态发生明显的变化。荆马河底泥中的重金属污染物主要以结合态和残渣态的形式存在,水溶态和交换态的量很小,经接种堆置处理后,水溶态和交换态量大幅削减,结合态和残渣态量有所增加,总量变化不大,生物学方法和化学方法测定都表明,处理后的底泥生物毒性有明显降低,重金属的生物有效性降低。     

浙江典型富硒区硒与重金属的形态分析

通过对浙江西部龙游地区富硒土壤中Hg、Cd、Pb、As等重金属含量的研究表明,成土母岩中与硒伴生的重金属含量较高,由于特殊的地形地貌、母岩风化物质搬运条件以及有利的土壤理化性质等,土壤中重金属大为减少。异常地段重金属形态分析结果表明:土壤中仅有Cd的全量、离子交换态、碳酸盐结合态和弱有机态较高,分别为0.6mg/kg、22.1%、26.5%、11.4%;Se全量平均为0.89 mg/kg,离子交换态、弱有机态含量分别为1.12%、26.4%,碳酸盐结合态仅为0.62%。尽管如此,区内莲子、稻米等农产品仍表现出高硒低重金属等特点,居民健康长寿,发硒含量高,从而为龙游县开发富硒农产品提供了有利条件。     

Spatial distribution,mineralogy, and weathering of heavy metals in soils along zinc-concentrate ground transportation routes: implication for assessing heavy metal sources

We investigated the source of heavy metals in soils at a site in South Korea, where a ground transportation of zinc-concentrates (ZnS, sphalerite) occurs daily. Seventy soil samples were collected at the site and analyzed for residual concentrations of heavy metals, as well as their chemical and mineralogical properties. Enrichment factor was calculated based on local geochemical background level of metals in soils and confirmed the contamination of soils in the area by an anthropogenic source. The concentration data were also subjected to a Pearson correlation analysis to determine the possible influences of anthropogenic sources and identify the primary source. A slight negative correlation between heavy metals and Al, and a weak correlation between heavy metals and Fe implied that the heavy metals originated from anthropogenic inputs rather than a geogenic source. A strong positive linear correlation between Zn and other heavy metals (i.e., As, Cd, Cu, Pb, r ≥ 0.96, p ≤ 0.001) suggested the influence of a single anthropogenic source of zinc-concentrates containing all of these heavy metals. Zinc-concentrate oxidation and leaching experiments, which mimicked physical and chemical weathering in the environment, indicated that zinc-concentrate could be transformed to zinc oxides and release Cd and Pb upon precipitation. The findings in this study provide an insight into the fate of the Zn that the original form of zinc-concentrate would not remain in the soil after long-term weathering, which should be considered when source of heavy metals is identified.     

珠江三角洲西部典型乡镇稻米与根系土重金属元素含量关系研究

农田土壤环境质量与稻米食用安全性关系非常密切,已有研究表明在采矿、交通、电子工业等影响下,珠三角地区积累了大量环境问题,镉汞砷等污染越来越严重。重金属在土壤-稻米系统中的迁移转化,受其总含量、土壤理化性质、有机质以及微量或大量元素的交互作用影响。为查明广东省佛山市高明区典型乡镇重金属在土壤-稻米系统中的迁移影响因素,为稻米食用安全性预测提供依据,本文在高明区明城镇、更合镇主要农田区,采集了151组稻谷及对应根系土样品,采用电感耦合等离子体发射光谱法(ICP-OES)、原子荧光光谱法(AFS)等技术测定了土壤重金属、养分元素含量、土壤理化指标以及稻米重金属含量,分析了重金属含量特征及其迁移的影响因子,建立并验证了稻米中重金属含量定量预测模型。结果表明:(1)土壤重金属含量均低于第一次全国土壤污染调查获得的广东省土壤重金属含量均值,并且均低于《土壤环境质量农用地土壤污染风险管控标准》(GB 15618—2018)中的土壤风险管制值,土壤污染风险低;(2)稻米中除Cd、Pb存在轻微超标外,其余重金属含量均低于食品卫生标准限值;(3)土壤重金属总量、土壤理化性质(土壤pH,土壤质地,土壤有机质含量,土壤N、P、K等)是重金属在土壤-稻米系统中迁移的关键控制因素。如土壤Cd、Cu总量与其在稻米中含量呈显著正相关;除Pb外,土壤有机质土壤全氮与各稻米中各重金属含量呈显著负相关;除Cd外,土壤全磷与稻米重金属含量呈显著负相关;土壤质地(SiO_2/Al_2O_3)与稻米各重金属含量均呈显著正相关;(4)根据随机抽取的130组数据,以土壤重金属总量及土壤理化指标为自变量,建立了稻米As、Cd、Cr、Cu、Hg、Ni、Pb含量多元回归方程,均达到显著相关,经剩余21组数据的验证,预测方程的平均误差的中位数与平均数最大为31%,最小为7.8%,总体来说预测效果较好,模型可以用来预测高明区及其相似地区的稻米重金属含量。本研究通过探讨土壤理化性质的影响,引入土壤大量营养元素作为影响因素进行探究,可为研究大量营养元素对土壤重金属迁移至稻米的影响以及科学施肥指导提供参考;同时获得的土壤-稻米系统元素迁移影响因素,可对开展重金属生物有效性研究以及水田土壤污染修复、相似地区生态风险评价提供参考;简单探讨了降低研究区重金属生物有效性的方法以及抑制重金属的迁移、降低重金属生物危害的措施,为探究重金属迁移规律特征与地方病、流行病之间的关系提供了思路。     

金昌市铜镍矿区周围土壤中重金属的迁移特征

对金昌矿区不同区域土壤5~20 cm层中重金属各化学形态及活性态的迁移行为进行了研究,结果表明：土壤中重金属不同化学形态迁移率不同,弱酸提取态、可还原态、可氧化态和残渣态平均迁移率分别为0.13、0.51、0.30和0.54。重金属总量和活性态（包括弱酸提取态、可还原态、可氧化态）迁移率也表现出很大差异,尾矿区土壤Cr总量迁移率较高为0.65,而其活性态迁移率较低为0.26,Ni与Cr迁移特征完全相反,总量迁移率为0.26,而活性态迁移率为0.67;农田土壤中Pb总量迁移率低而活性态迁移率高,Ni与Zn特征相似,总量迁移率高而活性态迁移率相对较低;大棚地土壤中重金属迁移率均较低,Cu和Ni活性态几乎未发生向下迁移。可见,重金属的迁移与其化学形态分布关系密切,与重金属总量的迁移率相比,活性态迁移率能够更有效地反映出土壤中重金属的迁移特征和潜在危害性。