电厂周围土壤重金属空间分布与风险评价研究

对宁夏地区大武口电厂周围土壤中铜、锌、铅和铬进行测定分析,利用不同的评价标准来评价其环境质量状况,同时借助GIS软件研究了污染指数的空间分布状况并解析了其重金属污染来源.结果表明,以自然背景值为评价标准,则大武口电厂周围土壤中的重金属都超过污染指标,其中铅和铬的污染较重;以国标二级为评价标准,则四种重金属的单项污染指数值全都小于1,其综合污染指数小于0.7,尚未受到污染.大武口电厂、大武口市区的公路交通及人为活动等可能是主要污染源.     

都江堰市城区周边农田土壤重金属污染状况分析与评价

以都江堰城区周边农耕地为对象,按照国标方法对土壤样本中的Cr、Cu、Cd、Pb、Zn五种重金属元素含量进行测定。结果表明,部分样本中的Cd、Cu含量超过国家土壤环境质量二级标准。采用单因子污染指数和土壤综合污染指数评价方法,以国家土壤环境质量二级标准为评价标准,对研究区内Cr、Cu、Cd、Pb、Zn重金属的污染状况进行评价,评价结果显示,Cu、Cd为主要污染元素,污染指数处于轻、中度污染,Cr、Pb、Zn对土壤尚未构成污染关系,研究区土壤重金属总体污染程度较轻。     

基于重金属有效态的农田土壤重金属污染评价研究

目前农田土壤重金属污染评价以重金属全量为依据,而评价农田土壤重金属污染影响时主要考虑农产品安全从而保障人体健康,农作物对重金属的吸收积累量则取决于土壤中有效态重金属含量。在阐述土壤重金属有效态定义的基础上,综合分析了土壤重金属有效态的影响因素及其与土壤中重金属全量和农作物中重金属含量的相关性,概括了土壤重金属有效态在土壤重金属污染评价中的应用,以期提出建立以土壤重金属有效态含量为基础、结合土壤重金属全量及作物中吸收的重金属含量的土壤重金属污染评价体系。     

焦作市中马村矿土壤重金属污染调查评价

对焦作市中马村矿矸石山周围土壤中5种重金属(Cu、Cr、Pb、Zn、Mn)的含量、分布特征及其污染状况进行了调查与评价。结果表明,矿区土壤不同程度地受到5种重金属的污染,依次为Zn>Pb>Cu>Cr>Mn;土壤综合污染指数为1. 74,属轻污染; 5种重金属元素中Zn、Pb相关性显著,其余均为低度相关。     

南京市郊区基本农田保护区土壤重金属污染调查

为调查基本农田保护区土壤环境中重金属污染状况，江苏省农业环境监测站于1999年和2001年分别对南京市郊区基本农田土壤环境质量进行了监测，共计布设监测点14个，监项目为镉，铅，砷，汞，铬和pH，结果表明，1999年土壤样品的重金属检出率为97．1％，超标率为5．7％，2001年重金属检出率为100％，超标率为1．4％，1999年土壤样品中超标的重金属元素是镉，超标率为28．6％，2001年超标元素是汞，超标率为7．1％，1999年土壤综合污染指数为1．08，污染等级及污染水平均属轻污染；2001年土壤综合污染指数为0．76，污染等级为警戒线，污染水平达到尚清洁。     

物元分析法在土壤重金属污染评价中的应用

针对实际中的土壤重金属污染状况是渐变的、模糊的,采用物元分析模型法通过建立物元矩阵,引用毒性响应系数对模型中权重的计算方法进行改进,并将改进的物元分析模型对广西环江某受铅锌矿影响的土壤重金属污染状况进行评价分析。结果表明,该区域土壤受重金属污染严重,尤其受Pb、Cd的影响更为严重,此评价结果符合当地的实际情况,同时与潜在生态危害指数评价结果一致,说明物元分析法在土壤重金属污染评价中的应用是合理的,其评价结果具有可靠性。     

污灌农田土壤镉污染状况及分布特征研究

对沈阳郊区某河沿岸部分乡镇的污灌农田土壤中重金属全镉含量进行了分析,评价了土壤镉污染状况,并探讨了该河沿岸土壤中镉的沿程分布特征、横向分布特征和垂向分布特征.结果表明,农田土壤重金属镉含量范围为0.15～8.23mg/kg,均值为1.75mg/kg.用土壤环境质量标准二级标准值对土壤中的全镉含量进行评价,平均镉污染指数为5.95,为重度污染;用土壤背景值标准评价,平均镉污染指数为5.95,超过当地背景值水平8.39倍,污灌已造成该地区重金属镉污染,且污染程度十分严重.该河渠从上游到下游,沿岸土壤镉含量呈降低趋势;横向分布上,距离该河渠越远,镉含量有逐渐减少的趋势;垂向分布上,表层土壤镉含量最高.     

内蒙古畜禽养殖场周边土壤重金属污染特征及评价

于2015年5—8月采集内蒙古自治区东部、中部和西部地区32个畜禽养殖场周边共160个土壤样品,分析8种重金属含量。通过单项污染指数法和内梅罗综合污染指数法评价畜禽养殖场周边土壤重金属的污染程度,主成分分析重金属污染的成因和来源。结果表明,除Hg和As外,Cd、Pb、Cr、Cu、Zn和Ni 6种重金属的平均值均高于内蒙古自治区土壤背景值,其中Cd是背景值的2. 14倍。单项污染指数评价表明,重金属Cd在东部畜禽养殖场周边土壤中呈中度污染,在中部和西部地区畜禽养殖场周边土壤中呈轻度污染。不同重金属元素平均污染程度为:Cd Pb Cr(Ni) Zn Cu As Hg。内梅罗综合污染指数评价表明,东部地区畜禽养殖场周边土壤污染最严重,为中度污染,中部和西部地区畜禽养殖场周边土壤均为轻度污染。不同地区畜禽养殖场周边土壤重金属内梅罗综合污染指数大小顺序为:东部地区(2. 27)西部地区(1. 52)中部地区(1. 35)。主成分分析结果显示,内蒙古不同地区畜禽养殖场周边土壤不同重金属的来源存在差异,其中Pb、Cr、Cu、Zn和Ni主要来源于畜禽粪便和冲洗禽舍等污水的不当排放; Hg主要来源于自然源。     

闽东某钼矿周边农田土壤钼和重金属的污染状况

调查了闽东某钼矿周边农田土壤和稻米钼及重金属的污染状况,对土壤钼的人体健康风险进行了评价,探讨了土壤钼的安全阈值。结果表明,部分土壤遭受了铜和镉的污染,以轻度污染为主;部分稻米出现镍和镉的污染,以轻度污染为主;土壤全钼含量为3.30~325.6 mg/kg,最高值高出福建省土壤中钼的环境背景值87倍,说明该区土壤已遭受严重的钼污染。稻米钼含量为0.58~12.04 mg/kg,对人体具有很高的健康风险;根据稻米钼含量与土壤钼含量之间的关系和人体健康风险评价结果,推算出土壤中钼(全钼)的安全阈值不高于4.51 mg/kg。     

乌鲁木齐市米东污灌区农田土壤重金属污染评价

对米东污灌区农田土壤重金属含量进行监测分析,利用不同的评价方法和标准对土壤重金属的环境质量进行评价。结果表明:米东污灌区农田土壤重金属含量分别为Cd(0.12±0.06)mg/kg,Cu(40.43±5.30)mg/kg,Zn(78.38±11.04)mg/kg,Pb(11.66±11.79)mg/kg,Ni(20.24±8.05)mg/kg,Cr(75.81±8.05)mg/kg。以国家土壤环境质量标准(二级)为标准评价,各元素的污染指数排序为Cu>Ni>Cr>Zn>Cd>Pb,综合污染指数为0.337,污染程度为安全。以食用农产品产地土壤环境质量要求为标准评价,各元素的污染指数排序为Cu>Ni>Cr>Zn>Cd>Pb,综合污染指数为0.343,污染程度为安全。表明米东污灌区农田土壤重金属含量尚能达到食用农产品产地土壤环境质量要求。Pb、Cu、Zn的平均含量超过乌鲁木齐市土壤背景值,这说明污灌区土壤重金属Pb、Cu、Zn近年来已有所累积,存在一定的污染风险。     

Status of heavy metals in agricultural soils as affected by different patterns of land use

This study was conducted to determine status of heavy metals in agricultural soils under different patterns of land use. A total of 38, 40 and 45 soil samples for bare vegetable field, greenhouse vegetable field, and grain crop field were respectively taken from surface layer (0–20 cm) from selected experimental areas away from suburbs of ten counties (or districts or cities) in four provinces or municipalities of Huabei plain in north China. Information of crop production history, including varieties, rotation systems and fertilizer use, at the corresponding sampling sites was surveyed. Soil total Cu, Zn, Cd, Pb, Cr, As and Hg were measured. The results showed that the contents of total Cu, Zn, Cd, Pb, Cr, As, and Hg in the soil samples, especially soil total Cu and Zn contents, were higher in the bare vegetable field and the greenhouse vegetable field than that in the grain crop field. Long-term use of excessive chemical fertilizers and organic manures in the bare vegetable field and the greenhouse vegetable field contributed to the accumulation of Cu, Zn, and other heavy metals in the soils. The contents of total Cu, Zn, and other heavy metals in soils increased with increasing vegetable production history of the research areas. In comparison with the grain crop field, the comprehensive pollution indices of the seven soil heavy metals and the single-factor pollution indices of soil Zn, Cu, Cd, Cr, and Hg based on the second criterion of Environmental Quality Standard for Soils were significantly higher in the bare vegetable field and the greenhouse vegetable field. Soils from the greenhouse vegetable field were slightly contaminated according to the comprehensive pollution index, and soils from the bare vegetable field and the grain crop field were at the warning heavy metal pollution level. The soils were contaminated with Cd according to the single-factor pollution index. The Cd pollution was relatively more serious in the bare vegetable field and the greenhouse vegetable field than that in the grain crop field. The soils selected with different land use patterns were not contaminated with Zn, Cu, Pb, Cr, As and Hg.     

杭州地区农业土壤中重金属的分布特征及其环境意义

为了分析杭州地区农业土壤重金属的分布特征及其环境意义,通过现场采样和室内分析检测的方法,对杭州市各区县不同作物农业土壤表层土中的Hg、As、Cu、Pb、Cr、Cd 6种重金属元素进行检测,并对其分布特征进行了分析。结果表明,杭州地区农业土壤中除As外,其他5种重金属的平均含量均低于且接近浙江省土壤背景值,个别采样点的重金属含量超过了土壤环境质量国家二级标准。总体上,杭州地区农业土壤处于安全水平。通过重金属的区域分布特征分析表明,余杭区和富阳市农业土壤中重金属平均含量普遍高于其他区域。萧山区和建德市部分农业土壤则存在Cu和Hg含量较高的情况,而淳安县农业土壤中重金属含量差异较大,土壤中出现了As、Cr和Cd含量最大值。不同作物的农业土壤重金属含量存在一定的差异,但不明显。水稻田和蔬菜地的土壤中,重金属含量较其他作物种植类型的土壤中含量高;叶菜类(蔬菜、茶叶)作物土壤中的Cd含量要比根茎类(水稻)、茄果类(水果)及其他作物种植类型的土壤中的含量低。目前杭州地区土壤中6种重金属含量均对作物的直接危害不大,但由于萧山区个别采样点Cu含量严重超标,淳安县土壤中Cd受外源性来源影响也已较明显,需要相关部门加大监管力度,防止污染事件发生。同时,为防止农业土壤中重金属含量进一步升高,需要加大大气降尘监测与治理、废气污染监管与控制治理。     

土壤重金属快速监测技术研究与应用进展

土壤重金属污染已经日益成为社会的主要环境污染问题之一,土壤重金属快速监测技术对于土壤重金属污染的快速有效筛查与监控具有重要意义。介绍了近年来国内外土壤重金属快速监测方法,并阐述了相关土壤重金属快速监测仪器的研究现状。在土壤重金属快速监测领域,X射线荧光光谱技术优势明显,激光诱导击穿光谱技术亦发展迅速,基于免疫学、酶抑制原理的快速监测技术正处于发展阶段。随着快速监测技术理论和方法的不断完善,土壤重金属快速监测仪器朝着高精度、小型化、智能化的方向发展,在区域性土壤重金属含量评估方面的应用将逐步拓展。     

Pollution, fractionation, and mobility of Pb, Cd, Cu, and Zn in garden and paddy soils from a Pb/Zn mining area

This study was conducted to investigate the pollution load index, fraction distributions, and mobility of Pb, Cd, Cu, and Zn in garden and paddy soils collected from a Pb/Zn mine in Chenzhou City, China. The samples were analyzed using Leleyter and Probst’s sequential extraction procedures. Total metal concentrations including Pb, Cd, Cu, and Zn exceeded the maximum permissible limits for soils set by the Ministry of Environmental Protection of China, and the order of the pollution index was Cd > Zn > Pb > Cu, indicating that the soils from both sites seriously suffered from heavy metal pollution, especially Cd. The sums of metal fractions were in agreement with the total contents of heavy metals. However, there were significant differences in fraction distributions of heavy metals in garden and paddy soils. The residual fractions of heavy metals were the predominant form with 43.0% for Pb, 32.3% for Cd, 33.5% for Cu, and 44.2% for Zn in garden soil, while 51.6% for Pb, 40.4% for Cd, 40.3% for Cu, and 40.9% for Zn in paddy soil. Furthermore, the proportions of water-soluble and exchangeable fractions extracted by the selected analytical methods were the lowest among all fractions. On the basis of the speciation of heavy metals, the mobility factor values of heavy metals have the following order: Cd (25.2–19.8%) > Cu (22.6–6.3%) > Zn (9.6–6.0%) > Pb (6.7–2.5%) in both contaminated soils.     

Heavy metal risk assessment for potatoes grown in overused phosphate-fertilized soils

The long-term application of phosphate fertilizers on vegetable production fields has raised concerns about the potential health risks of heavy metal contamination of crops grown on contaminated soils in the Hamadan province, western Iran. This study found that long-term fertilizer use led to a growing accumulation of heavy metals in soils. High concentrations of elemental As, Cd, Cr, Cu, Pb, and Zn were found in potatoes sampled from overused phosphate-fertilized soils, which increased the daily intake of metals in food. However, the ingestion of potatoes from soils affected by phosphate fertilizers posed a low health risk when compared with the health risk index of <1 for heavy metals. Nevertheless, heavy metal concentrations should be periodically monitored in vegetables grown in these soils. It would also be beneficial to implement effective remediation technologies to minimize possible impacts on human health.     

典型涉污企业周边土壤重金属污染特征及潜在生态风险评价

分析和评价典型涉污企业周边土壤环境质量,对于加强企业用地环境风险管控,实施土壤重金属污染精准防控,进一步保障农产品质量安全具有重要意义。以18类典型涉污企业周边土壤为研究对象,对475家企业周边的2 017个监测样点进行土壤重金属Cd、As、Pb、Hg、Cr、Cu、Zn和Ni元素含量测定,并采用主成分分析法、Hakanson 潜在生态风险指数法进行分析及评价。结果表明:典型涉污企业周边土壤重金属污染以Cd、Pb和As元素为主,各元素含量超过土壤污染风险筛选值的样品比例为9.82%~31.0%,超过土壤污染风险管控值的样品比例为4.46%~13.1%,其次是Zn、Cu、Hg和Ni,Cr无明显污染;主要污染元素Cd、Pb、As、Zn和Cu来自相同污染源且主要分布在有色金属矿采选业(B9)、黑色金属冶炼和压延加工业(C31)、有色金属冶炼和压延加工业(C32)、生态保护和环境治理业(N77)等行业企业周边;黑色金属冶炼和压延加工业(C31)、有色金属矿采选业(B9)、有色金属冶炼和压延加工业(C32)等行业企业周边土壤重金属潜在生态风险等级较高,中等风险及以上比例分别为76.0%、53.0%和54.1%。可见,典型涉污企业周边土壤重金属存在一定程度的污染,尤其是有色金属矿采选业(B9)等采矿业以及黑色金属冶炼和压延加工(C31)等制造业等,污染程度高,潜在生态风险大,需要加强监测和管控。     

Impact of overland traffic on heavy metal levels in highway dust and soils of Istanbul, Turkey

The purpose of this study was to investigate the impact of overland traffic on the spatial distribution of heavy metals in urban soils (Istanbul, Turkey). Road dust, surface, and subsurface soil samples were collected from a total of 41 locations along highways with dense traffic and secondary roads with lower traffic and analyzed for lead (Pb), zinc (Zn), and copper (Cu) concentrations. Statistical evaluation of the heavy metal concentrations observed along highways and along the secondary roads showed that the data were bimodally distributed. The maximum observed Pb, Zn, and Cu concentrations were 1,573, 522 and 136 mg/kg, respectively, in surface soils along highways and 99.3, 156, and 38.1 mg/kg along secondary roads. Correlation analysis of the metal concentrations in road dust, surface and 20-cm depth soils suggests the presence of a common pollution source. However, metal concentrations in the deeper soils were substantially lower than those observed at the surface, indicating low mobility of heavy metals, especially for Pb and Zn. A modified kriging approach that honors the bimodality of the data was used to estimate the spatial distribution of the surface concentrations of metals, and to identify hotspots. Results indicate that despite the presence of some industrial zones within the study area, traffic is the main heavy metal pollution source.     

我国高速公路周边土壤重金属污染现状及研究进展

以我国高速公路周边土壤重金属为研究对象，综述了我国高速公路周边土壤重金属污染特征、影响因素、来源、环境风险及其研究进展。高速公路周边土壤主要受Pb、Cd、Cr、Cu、Zn等重金属污染，主要呈现指数分布、偏态分布和两者混合分布等特点，并且受到土地利用、风向、地形、车流量等多种因素的综合影响。土壤重金属的来源除了受成土母质等自然因素影响以外，公路交通和周边工农业活动也会对其来源产生较大影响。传统的土壤重金属评价方法主要采用单因子指数法、地累积指数法、生态风险评价法等对重金属的污染等级和环境风险进行评价。未来的研究应将重金属形态分析、空间和地统计分析、重金属稳定同位素示踪和源解析模型以及预测模型等多种手段相结合，开展高速公路周边土壤重金属的污染特征、时空分布、来源及预测预警研究等，为我国高速公路沿线工农业生产布局及其土壤重金属污染防控提供科学依据和决策支撑。     

Heavy Metal Load Of Soil, Water And Vegetables In Peri-Urban Delhi

Peri-urban lands are often used for production of vegetables for better market accessibility and higher prices. But most of these lands are contaminated with heavy metals through industrial effluents, sewage and sludge, and vehicular emission. Vegetables grown in such lands, therefore, are likely to be contaminated with heavy metals and unsafe for consumption. Samples of vegetables i.e., spinach (Spinacia oleracea L.) and okra (Abelmoschus esculentus L.); soil and irrigation water were collected from 5 peri-urban sites of New Delhi to monitor their heavy metal loads. While heavy metal load of the soils were below the maximum allowable limit prescribed by the World Health Organization (WHO), it was higher in irrigation water and vegetable samples. The spinach and okra samples showed Zn, Pb and Cd levels higher than the WHO limits. The levels of Cu, however, were at their safe limits. Metal contamination was higher in spinach than in okra. Spatial variability of metal contamination was also observed in the study. Bio-availability of metals present in soil showed a positive relationship with their total content and organic matter content of soil but no relationship was observed with soil pH. Washing of vegetables with clean water was a very effective and easy way of decontaminating the metal pollution as it reduced the contamination by 75 to 100%.     

Soil Contamination Due to Heavy Metals from an Industrial Area of Surat, Gujarat, Western India

The pollution of soil is a source of danger to the health of people, even to those living in cities. The anthropogenic pollution caused by heavy industries enters plants then goes through the food chain and ultimately endangers human health. In the context, the knowledge of the regional variability, the background values and anthropogenic vs. natural origin of potentially harmful elements in soils is of critical importance to assess human impact. The present study was undertaken on soil contamination in Surat, Gujarat (India). The aims of the study were: i) to determine extent and distribution of heavy metals (Ba, Cu, Cr, Co, Ni, Sr, V and Zn) ii) to find out the large scale variability, iii) to delineate the source as geogenic or anthropogenic based on the distribution maps and correlation of metals in soils. Soil samples were collected from the industrial area of Surat from top 10 cm layer of the soil. These samples were analysed for heavy metals by using Philips PW 2440 X-ray fluorescence spectrometer. The data reveal that soils in the area are significantly contaminated, showing higher levels of toxic elements than normal distribution. The heavy metal loads of the soils in the study area are 471.7 mg/kg for Ba, 137.5 mg/kg for Cu, 305.2 mg/kg for Cr, 51.3 mg/kg for Co, 79.0 mg/kg for Ni, 317.9 mg/kg for Sr, 380.6 mg/kg for V and 139.0 mg/kg for Zn. The higher concentrations of these toxic metals in soils need to be monitored regularly for heavy metal enrichment.