攀西地区主要蔬菜基地土壤重金属含量及评价

对攀西地区米易县蔬菜基地的土壤进行采样,用原子吸收和石墨炉光谱法分析土壤中Cr、Cu、Ni、Zn、Pb、Cd、As和Hg8种元素的含量。蔬菜基地土壤重金属平均含量分别为Cr 68．8mg／kg、Cu 22．3mg／kg、Ni27．6mg／kg、Zn 146．2mg／kg、Pb31．7mg／kg、Cd0．258mg／kg、As10．3mg／kg、Hg0．0618mg／kg。根据土壤环境质量标准（GB15618—1995）对检测结果进行了单因子和多因子综合污染指数评价。分析表明调查区内少部分蔬菜基地土壤受到轻度重金属污染,主要污染物为Cd元素,其余重金属元素的含量均在安全警戒线内。     

广西贵港柑桔产区土壤重金属污染及生态风险评价

以广西贵港柑桔产区土壤为研究对象,分析了土壤中As、Hg、Cd、Cr、Cu、Sc、Pb、Zn 8种重金属含量及污染特征,基于农用地土壤污染评价标准(GB15618-2018),利用潜在生态危害指数法评价了该产区重金属的综合潜在生态风险。结果表明:Cr、Ni、Cu、Zn、As、Hg、Pb 7种元素含量均值低于土壤污染风险筛选值,Cd元素含量均值(1. 22mg/kg)高于风险筛选值(0. 3mg/kg)。Pb、Zn元素与Hg、Ni元素各自具有相似的空间分布规律,Cd元素含量有从中心向四周扩散的趋势。Cd元素处于较强的风险水平,很强与极强级别样本所占比例分别为17. 5%和45%。Hg元素中度、强风险级别占比分别为39. 5%、29. 5%,说明该研究区土壤中Cd、Hg元素污染较严重。综合潜在风险指数RI均值为342. 4,属于强生态风险,主要受Cd、Hg元素污染影响。     

河南农田土壤重金属污染状况及其评价

在河南境内取自农田土壤102例表层样品，分析了其中的Cr、Zn、Cu、Pb、Ni、As等8种重金属元素的含量。结果表明：河南农田土壤中除Cr偶有超出我国《土壤环境质量标准》（GB15618—1995）二级标准的土样外，其他项目均不超标，重金属污染由高到低排序为Cr〉Zn〉Ni〉Cd〉Hg〉Cu〉Pb〉As。重金属元素在河南各土壤利用类型中分布规律不明显，按4种主要土壤利用类型考查来看，重金属污染程度大小排序为：果园地〉水田〉菜地〉其他粮田；河南农田土壤综合污染指数总平均为0．981，土壤总体为尚清洁，重金属污染处于警戒水平；河南农田土壤中Cr含量较高的土壤主要是粗骨土与石质土，其天然本底值较高。     

宝鸡市大气降尘中重金属元素来源分析

解析宝鸡市区大气降尘中重金属元素的来源，评价7个元素的浓度含量，为宝鸡地区大气污染防治提供参考依据。利用火焰原子吸收分光光度法对样品中所含有的Pb、Zn、Cu、Cd、Cr、Ni和Fe七种重金属元素采用相关性与富集因子分析法进行了研究分析。分析表明，Pb与Cd相关性明显，Cr和Ni主要来源于土壤颗粒，Pb、Zn和Cu可能叠加了人为污染，Cd元素局部污染严重。由数据对照分析可知，宝鸡市区整个大气环境质量有明显的提高，Pb、Zn和Cu元素在市区中部和西部均有明显的降低，而东部新增点位相对污染较重，Cd元素含量较高，应该与该地区工业污染有关。     

广西车河矿区表层土壤重金属污染及风险评价

以广西河池某矿区公路沿线的土壤样品作为研究对象,分析土壤中Cu、Cr、Pb、Zn、Ni、Cd 6种重金属含量及分布特征,采用潜在危险生态指数法对土壤环境质量进行评价。研究结果表明:矿区周边沿线表层土壤中重金属的平均含量普遍较高,Cu、Cr、Pb、Zn、Ni、Cd平均含量分别为41.97mg/kg、58.67mg/kg、98.52mg/kg、589.06 mg/kg、24.06mg/kg、5.09 mg/kg,均高出了当地的背景值;用Hakanson潜在危险生态指数法研究表明,6种重金属对对该地区的生态风险影响程度由高到低为:CdPbZnCuNiCr,说明该区的主要生态风险因素是Cd。     

吉林省镍矿区玉米体内重金属累积分布规律及其与土壤重金属全量的关系

矿山开采和冶炼可对矿区土壤造成不同程度的重金属污染。为了明确吉林省镍矿区耕地土壤/植物体系中重金属的迁移累积规律,在吉林省镍矿区采集了27个区域的土壤和玉米植株样品。结果表明,吉林省镍矿区土壤p H为5.00~6.82,有机质的含量为2.79%~7.93%,部分采样点的Cd和Pb超出吉林省土壤背景值,大部分采样点的Cu和Ni超出吉林省土壤背景值,所有采样点的Zn超出吉林省土壤背景值。玉米籽粒中Cd和Pb未检出,玉米茎中Cd未检出,27个采样点中有23个采样点的玉米籽粒Ni含量超过我国粮食及制品中重金属限量标准(NY 861-2004),而仅有4个采样点的籽粒Zn含量超过我国限量标准,所有采样点的籽粒Cu含量明显低于我国限量标准。随土壤重金属全量增加,玉米根Cd,Cu,Ni,Pb和Zn含量均呈增加趋势,其中根Cd,Cu,Ni含量与土壤重金属Cd,Cu,Ni全量呈显著正相关,而根Pb和Zn含量与土壤重金属Pb和Zn全量相关性不显著。     

黑岱沟露天煤矿排土场周边土壤重金属污染分析

为阐明黑岱沟露天煤矿排土场周边土壤重金属污染现状，应用单因子污染指数法和潜在生态危害指数法对土壤中Cd、Cu、Mn、Ni、Zn和Pb元素的污染状况进行分析。结果表明：以内蒙古土壤背景值为标准，矿区排土场周边土壤中Cd元素(P_i>5)属于重度污染为特征污染物；Cu和Ni(1i ≤2)处于微污染水平；Mn、Zn和Pb元素(P_i<1)未达到污染水平。Cd元素各样点分布不均，变异系数较大，说明该元素的富集受人类活动的影响严重，应对其进行监测与防治。该研究可为黑岱沟露天煤矿排土场周边土壤重金属污染防治及生态修复提供依据。     

喀什地区土壤元素背景值研究

测定了喀什地区12种必测元素Cu、Pb、Zn、Cd、Ni、Cr、Hg、As、Co、Mn、V、F的土壤元素背景值和该地区主要土壤剖面的48种元素的土壤元素背景值。分析研究了喀什地区主要土壤类型和母质类型的元素背景值,阐述了该地区地形、地貌以及海拔高度对土壤元素背景值含量的影响。     

四川省马边磷矿区水环境中典型重金属污染分析

马边磷矿区磷矿资源丰富,区内磷矿开采企业较多。在开采的过程中难免会对当地的河水造成一定的影响。为了进一步了解马边磷矿区的环境影响问题,本文通过对磷矿区采集的水体样品和同一地点的水系沉积物样品进行分析测试,共检测了Cd、As、Cu、Cr、Pb、Zn六种重金属元素的含量,采用潜在生态危害指数法对沉积物中的重金属污染程度进行了综合评价。结果如下:马边磷矿区河水中的重金属元素的浓度较低,6种重金属元素含量均低于国家标准(GB3838-2002)。水系沉积物中的重金属元素含量较高,其中:Cd、Pb、Zn分别为2. 06mg/kg、182. 39mg/kg、479. 13 mg/kg。与四川省土壤元素背景值相比:Cd元素超标25. 7倍,Pb元素超标5. 9倍,Zn元素超标5. 5倍,其余元素未超标。与马边地区1∶20万区域水系沉积物背景值相比:Cd元素超标3. 12倍,Pb元素超标3. 3倍,Zn元素超标2. 5倍,As元素超标1. 6倍,Cu、Cr元素含量在背景值以内。与“中国土壤元素背景值”相比:Cd元素超标29. 4倍,Pb元素超标7. 7倍,Zn元素超标7. 1倍。潜在生态危害指数法评价结果表明:Cd的生态危害指数最大,其次为Pb和As,其余Cu、Cr、Zn等元素属于轻微生态风险。     

攀枝花市攀钢工业区土壤重金属污染特征及评价

本文对攀枝花市攀钢工业区土壤中五种重金属元素（Cu、Pb、Zn、Cr、Cd）的空间的分布特征、形态分布特征进行了研究，并应用污染负荷指数法对各重金属的污染程度进行了评价。研究发现，Cu、Pb、Zn、Cr的最大值与最小值分别相差2．98、3．4、5．2、2．7倍，cd的最大值与最小值甚至相差15．7倍。重金属元素相关性特征可分为Cd—Pb—Zn和Cu—Cr两组。形态分布特征表现在Cu、Zn、Pb、Cr主要以稳定的残渣态存在，Cd主要以可利用性最强的可交换态和碳酸盐结合态存在。污染较严重的是攀钢机关、攀钢原料场。     

不同酸消解方法在土壤重金属测定中的比较研究

分别用三种不同的酸消解方法进行土壤标准样品的前处理,用原子吸收分光光度法测定其中铜、铅、锌、镉、镍、锰、总铬元素的含量。结果表明,电热板/硝酸-过氧化氢-氢氟酸消解方法耗酸量少,消解时间短,适用于土壤中铜、铅、锌、镉、镍、锰元素的前处理,相对标准偏差为1.0%～5.0%;而使用电热板/硝酸-硫酸-氢氟酸方法针对土壤中总铬元素进行消解前处理,准确度更高,相对标准偏差为2.7%～5.1%。     

Heavy metal content and distribution in surface sediments of the Seyhan River, Turkey

Chemical fractionation of seven heavy metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) was studied using a modified three-step sequential procedure to assess their impacts in the sediments of the Seyhan River, Turkey. Samples were collected from six representative stations in two campaigns in October 2009 and June 2010, which correspond to the wet and dry seasons, respectively. The total metal concentrations in the sediments demonstrated different distribution patterns at the various stations. Cadmium was the only metal that was below detection at all stations during both sampling periods. Metal fractionation showed that, except for Mn and Pb, the majority of metals were found in the residual fraction regardless of sampling time, indicating that these metals were strongly bound to the sediments. The potential mobility of the metals (non-residual fractions) is reflected in the following ranking: Pb > Mn > Zn > Cu > Ni > Cr in October 2009 and Mn > Pb > Zn > Cu > Ni > Cr in June 2010. The second highest proportion of metals was bound to organic matter/sulfides, originating primarily from anthropogenic activities. Non-residual metal fractions for all stations were highest in June 2010, which may be linked to higher organic matter concentrations in the sediment samples with 1.40% and 15.1% in October 2009 and June 2010, respectively. Potential sediment toxicity was evaluated using the Risk Assessment Code (RAC). Based on RAC classification, Cd and Cr pose no risk, Cu and Ni pose low risk, Pb and Zn were classified as medium risk metals, while the environmental risk from Mn was high. In addition, based on the sediment quality guidelines (SQG), the Seyhan River can be classified as a river with no, to moderate, toxicological risks, based on total metal concentrations.     

Total Contents and Sequential Extraction of Heavy Metals in Soils Irrigated with Wastewater,Akaki, Ethiopia

The Akaki River, laden with untreated wastes from domestic, industrial, and commercial sources, serves as a source of water for irrigating vegetable farms. The purpose of this study is to identify the impact of waste-water irrigation on the level of heavy metals and to predict their potential mobility and bioavailability. Zn and V had the highest, whereas Hg the lowest, concentrations observed in the soils. The average contents of As, Co, Cr, Cu, Ni, Zn, V, and Hg of both soils; and Pb and Se from Fluvisol surpassed the mean + 2 SD of the corresponding levels reported for their uncontaminated counterparts. Apparently, irrigation with waste water for the last few decades has contributed to the observed higher concentrations of the above elements in the study soils (Vertisol and Fluvisol) when compared to uncontaminated Vertisol and Fluvisol. On the other hand, Vertisol accommodated comparatively higher average levels of Cr, Cu, Ni, Zn, etc V, and Cd, whereas high contents of Pb and Se were observed in Fluvisol. Alternatively, comparable levels of Co and Hg were found in either soil. Except for Ni, Cr, and Cd in contaminated Vertisol, heavy metals in the soils were not significantly affected by the depth (0–20 and 30–50 cm). When the same element from the two soils was compared, the levels of Cr, Cu, Ni, Pb, Se, Zn, V, Cd at 0–20 cm; and Cr, Ni, Cu, Cd, and Zn at 30–50 cm were significantly different. Organic carbon (in both soils), CEC (Fluvisol), and clay (Vertisol) exhibited significant positive correspondences with the total heavy metal levels. Conversely, Se and Hg contents revealed perceptible associations with carbonate and pH. The exchangeable fraction was dominated by Hg and Cd, whereas the carbonate fraction was abounded with Cd, Pb, and Co. conversely, V and Pb displayed strong affinity to reducible fraction, where as Cr, Cu, Zn, and Ni dominated the oxidizable fraction. Cr, Hg, Se, and Zn (in both soils) showed preference to the residual fraction. Generally, a considerable proportion of the total levels of many of the heavy metals resided in non residual fractions. The enhanced lability is generally expected to follow the order: Cd > Co > Pb > Cu > Ni > Se > V and Pb > Cd > Co > Cu > Ni > Zn in Vertisol and Fluvisol, respectively. For the similar wastewater application, the soil variables influence the status and the distribution of the associated heavy metals among the different soil fractions in the study soils. Among heavy metals that presented relatively elevated levels and with potential mobility, Co, Cu, Ni (either soil), V (Vertisol), Pb, and Zn (Fluvisol) could pose health threat through their introduction into the food chain in the wastewater irrigated soils.     

Characteristic levels of heavy metals in soil profiles of automobile mechanic waste dumps in Nigeria

The characteristic levels of heavy metals (Cd, Cr, Cu, Pb, Ni and Zn) of soil profiles of automobile mechanic waste dumps were studied. The concentration of heavy metals decreased with the depth of the profile and lateral distance from the dumpsites. The levels found in this study exceeded background concentrations and limits for agricultural and residential purposes. The distribution pattern of heavy metals in the soil profiles were in the following order Pb > Zn > Cu > Cd > Ni > Cr. The mechanic waste dumps represent potential sources of heavy metal pollution to environment. The elevated levels of heavy metals in these soil profiles constitute a serious threat to both surface and groundwater.     

玉米植株各器官中重金属含量相关性的研究

为探讨大宗粮食作物玉米植株各器官中重金属含量的相关性,选择6个玉米品种进行盆栽实验。盆栽试验的土壤来自西南某省铅锌矿区。研究结果表明,(1)6个供试品种植株籽粒中,Ni、Pb、Zn的含量全部超标;部分品种玉米中的Cd含量超标;6个供试品种植株玉米中的Cr、Cu含量全部达标。(2)重金属含量在玉米各器官中存在交互效应;如,供试植株叶片中Cu与Ni、Pb与Zn分别存在显著正相关;在供试植株的叶片和茎秆中,Cd、Pb、Zn三者的含量呈显著性正相关。(3)金属Ni在供试植物茎秆与籽粒中存在交换的情况;金属Pb的含量在供试植株根部与茎秆的差异较大,其可能原因是植株茎秆对铅的吸收达到了饱和上限;金属Zn的含量在植株籽粒与茎秆中的差异较大,主要是因为Zn在玉米植株内的移动性强,且Zn最容易在籽粒中积累。     

Major and trace elements of selected pedons in the USA

Few studies of soil geochemistry over large geographic areas exist, especially studies encompassing data from major pedogenic horizons that evaluate both native concentrations of elements and anthropogenically contaminated soils. In this study, pedons (n = 486) were analyzed for trace (Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Zn) and major (Al, Ca, Fe, K, Mg, Na, P, Si, Ti, Zr) elements, as well as other soil properties. The objectives were to (i) determine the concentration range of selected elements in a variety of U.S. soils with and without known anthropogenic additions, (ii) illustrate the association of elemental source and content by assessing trace elemental content for several selected pedons, and (iii) evaluate relationships among and between elements and other soil properties. Trace element concentrations in the non-anthropogenic dataset (NAD) were in the order Mn > (Zn, Cr, Ni, Cu) > (Pb, Co) > (Cd, Hg), with greatest mean total concentrations for the Andisol order. Geometric means by horizon indicate that trace elements are concentrated in surface and/or B horizons over C horizons. Median values for trace elements are significantly higher in surface horizons of the anthropogenic dataset (AD) over the NAD. Total Al, Fe, cation exchange capacity (CEC), organic C, pH, and clay exhibit significant correlations (0.56, 0.74, 0.50, 0.31, 0.16, and 0.30, respectively) with total trace element concentrations of all horizons of the NAD. Manganese shows the best inter-element correlation (0.33) with these associated total concentrations. Total Fe has one of the strongest relationships, explaining 55 and 30% of the variation in total trace element concentrations for all horizons in the NAD and AD, respectively.     

Fate of biosolids trace metals in a dryland wheat agroecosystem

Biosolids land application for beneficial reuse applies varying amounts of trace metals to soils. Measuring plant-available or total soil metals is typically performed to ensure environmental protection, but these techniques do not quantify which soil phases play important roles in terms of metal release or attenuation. This study assessed the distribution of Cd, Cr, Cu, Mo, Ni, Pb, and Zn associated with soluble/exchangeable, specifically adsorbed/carbonate-bound, amorphous Mn hydroxyoxide-bound, amorphous Fe hydroxyoxide-bound, organically complexed, and residual inorganic phases. Biosolids were applied every 2 yr from 1982 to 2002 (except in 1998) at rates of 0, 6.7, 13.4, 26.8, and 40.3 dry Mg biosolids ha(-)(1) to 3.6- by 17.1-m plots. In 2003, 0- to 20-cm and 20- to 60-cm soil depths were collected and subjected to 4 mol L(-1) HNO(3) digestion and sequential extraction. Trace metals were concentrated in the 0- to 20-cm depth, with no significant observable downward movement using 4 mol L(-1) HNO(3) or sequential extraction. The sequential extraction showed nearly all measurable Cd present in relatively mobile forms and Cr, Cu, Mo, Ni, Pb, and Zn present in more resistant phases. Biosolids application did not affect Cd or Cr fractionation but did increase relatively immobile Cu, Mo, and Zn phases and relatively mobile Cu, Ni, and Pb pools. The mobile phases have not contributed to significant downward metal movement. Long-term, repeated biosolids applications at rates considered several times greater than agronomic levels should not significantly contribute to downward metal transport and ground water contamination for soils under similar climatic conditions, agronomic practices, and histories.     

Multivariate statistics to investigate metal contamination in surface soil

The modification of soil composition in the urbanized area of Ankara due to wet-dry deposition and pollution-derived particles from the atmosphere is investigated by analyzing 120 surface soil samples, collected from the urbanized area and its un-urbanized surrounding, for major, minor and trace elements. Concentrations of elements from human activity (e.g. Cd, Pb, Cr, Zn, Cu and Ca) in the urbanized area were higher than their corresponding concentrations in global average soil and soil in un-urbanized areas outside the urbanized area. Metal contents in soil were very high in densely populated districts and around some industrial facilities. The only exception was Pb distribution, which was more dispersed, due to the nature of motor vehicle emissions. Alteration of the Cd, Zn, Cu and Cr content of soil was confined to the inhabited and industrial areas, whereas enrichment factors of these elements were close to unity in the remaining study area. Factor analysis identified two polluted soil factor associations. One factor includes elements, such as Zn and Cd, which had high factor scores in inhabited areas and the other factor (high loading of Pb) represents soil polluted by motor vehicle emissions.     

Characteristic levels of heavy metals in sediments and dredged sediments of a municipal creek in the Niger delta, Nigeria

Characteristic levels of metal ions in post dredged sediment and dredged sediments materials of a municipal creek in the Niger Delta show that significant concentrations of heavy metals are found to be accumulated more on the surface (0–15cm depth) of the dredged material as compared to the sub surface (15–30cm) and post dredged sediments. The distribution patterns were in the following order Fe > Mn > Zn > Cu > Pb > Ni > Cd and Fe > Mn > Zn > Pb > Cu > Ni > Cd for the post dredged sediment and dredged sediment materials respectively. The levels of the various metals were far below the EPA screening levels for open water disposal, consequently total levels of heavy metal found in these sediments pose no problem by open-water or upland disposal