Heavy Metal Contamination in Peach Trees Irrigated with Water from a Heavily Polluted Creek

This study was conducted to characterize the heavy metal contamination in the soils of peach orchards irrigated with water from Nilüfer creek, which is heavily polluted by industrial and municipal wastes. Twenty-one peach orchards with 3 different cultivars in 7 orchards each located along Nilüfer creek were monitored in the experiment. To determine levels of pollution, soils and aboveground parts of the trees were sampled and analyzed for iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), cobalt (Co), nickel (Ni), chromium (Cr), lead (Pb), and cadmium (Cd). Total amounts of Ni and Cr were found to be at the excessive levels in soils. Extractable Ni concentration decreased with increasing pH and CaCO₃ content in soils. Leaf metal contents were generally at tolerable levels, but Ni and Pb accumulated to toxic levels in different parts of the fruit (flesh and peel). Except for Fe and Ni, plant concentrations of the metals did not correlate with their total and DTPA-extractable concentrations in the soils. There was no significant difference among the cultivars in accumulation of heavy metals.     

Toxic Metal Removal from Polluted Soil by Acid Extraction

Sulfuric acid leaching is a promising technique to extract toxic metals from polluted soils. The objective of this study was to define the optimum sulfuric acid leaching conditions for decontamination of the fine particle fraction (<125???m) of an industrial soil polluted by Cd (16.8?mg?kg^?1), Cu (3,350?mg?kg^?1), Pb (631?mg?kg^?1) and Zn (3,010?mg?kg^?1). Batch leaching tests in Erlenmeyer shake flasks showed that a soil pulp pH between 1.5 and 2.0 using a solid concentration (SC) ranging from 5 to 20?% is adequate to efficiently solubilize toxic metals. Leaching tests performed at different temperatures (20, 40, 60 and 80?°C) also revealed that it is not beneficial to heat the soil suspension during the leaching treatment. The application in a 1-L stirred tank reactor of five consecutive 1-h leaching steps at 10?% SC and ambient temperature, followed by three water washings steps resulted in the following metal extraction yields: 30?% As, 90?% Cd, 43?% Co, 7?% Cr, 88?% Cu, 75?% Mn, 26?% Ni, 18?% Pb and 86?% Zn. The decontaminated soil conformed to Quebec norms for commercial and industrial use of soil.     

中南大型有色金属冶炼厂周边农田土壤重金属污染特征研究

以中南地区某大型有色金属冶炼厂周边耕地为对象,采集0~20 cm表层土壤,测定其基本性质及重金属浓度,分析了重金属元素间及重金属污染程度与距冶炼厂远近的相关关系,以判别研究区土壤重金属污染来源及空间分布规律。结果表明,研究区土壤呈酸性,土壤重金属污染以Cd为主,与当地土壤环境背景值和国家土壤环境质量二级标准相比,超标率分别达60.9%、86.1%。Cu、Zn、Cr、Ni等元素的污染较轻,Pb则未超标。内梅罗综合污染指数法对水田土壤重金属的风险评价显示该区属于安全的点位仅占8.7%,农产品生产存在较高风险。单因素方差分析显示旱地与水田土壤重金属浓度差异不显著,说明耕作方式不是造成该区重金属分布差异的主要原因。土壤Cd与Pb、Zn浓度显著相关,且与距冶炼厂的距离呈显著负相关,指数和幂函数均能很好地拟合重金属浓度随距离变化的分布模式,说明三者可能均来源于冶炼厂的降尘污染。     

Metal Contamination of River Waters and Sediments from Effluents of Kaolin Processing in Brazil

In order to evaluate the metal contamination from kaolin industry discharges into rivers in the State of Minas Gerais, Brazil, samples of river water and fluvial sediment were collected up- and down-river from the industries and analysed todetect metal inputs. The metal examined included zinc, iron, andaluminium among others, being selected due to their toxicity andoccurence in waste waters. Metal inputs in the samples analysed appeared to be related to effluent discharges into the rivers. The river water showed high concentrations (in μg mL^-1) of Zn (355), Fe (354) and Al (303). Sediment investigations indicated heavy enrichment (SEF = 9.4) for Zn. The Geoaccumulation Index for this element accounted for 3 (moderately to heavy polluted). River water pH of the sample collected near the effluent discharge site reached 3.7, suggesting inadequate treatment.     

Metal Contamination in Nullah Dek Water and Accumulation in Rice

A research study was carried out to determine the electrical conductivity （EC）, residual sodium carbonate （RSC）, sodium adsorption ratio （SAR）, pH and metals in metal-polluted irrigation water from a nullah and those in soils over a period of time, and the effect of metals on rice yield and metal concentrations in rice grain and straw. Two sites （I and If） were selected on the bank of Nullah Dek at Thatta Wasiran in Sheikhupura District （Pakistan）, with two rice varieties, Super Basmati and Basmati 385, at both sites. Water samples were collected during rice crop growth at 15-day intervals from August 3 to November 1, 2002. The results showed that Nullah Dek water had an EC 〉1.0 dS m^-1 and RSC of 2.78-4.11 mmolc L^-1, which was hazardous for crops, but the SAR was within the safe limit. Cu, Mn Cd and Sr were also within safe limits. The soil analysis showed that Site Ⅱ was free from salinity/sodicity, whereas Site Ⅰ was saline sodic. Among metals, Zn was sometimes deficient, Cu, Mn and Fe were adequate, and St, Ni and Cd were within safe limits in the soil at both the sites. After the rice crop harvest, concentrations of all metals tested were usually slightly increased, being higher in the upper soil layer than the lower. In addition, Basmati 385 produced higher rice grain and straw yield than Super Basmati. Chemical analysis of rice grain indicated the presence of Zn, Cu, Fe, Mn, Pb and Sr, whereas rice straw contained Zn, Cu, Fe, Mn and Sr, with Cd and Ni both being found in minute quantities.     

金属硫蛋白作为重金属污染生物标志物的研究进展

金属硫蛋白（MT）是一类普遍存在于生物体内的低分子量、富含半胱氨酸、热稳定性、可诱导型非酶蛋白,具有维持生物体内金属含量动态平衡和重金属解毒作用双重机制。大量研究表明,MT可作为重金属污染的生物标志物,用来预测生物体受重金属暴露的状况和重金属污染的压力,且对制定预防性的管理措施、及时监控环境污染皆具有重要的现实意义。本文根据国内外文献资料查阅及综合分析,主要阐述了金属硫蛋白的基本结构、多态性、生理功能及其作为生物标志物在环境污染检测与诊断方面的研究与应用,并展望其今后研究方向。     

Identifying the Sources and Contamination Status of Potentially Toxic Trace Elements in Agricultural Soils

Elevated concentrations of potentially toxic trace elements in agricultural soils contribute to soil pollution affecting food quality and safety. We assessed pollution levels in agricultural systems, lowland rice (LL) and highland cash crops (HL), by comparing with non-agricultural soils (NA). Correlation analysis and principal component analysis (PCA) were performed, and geo-accumulation index (I_geo) and pollution loading index (PLI) were calculated. Zinc in LL, and Cd in LL and HL, were significantly higher than in NA. The I_geo values of cooper (Cu), lead (Pb), nickel (Ni), zinc (Zn), and cadmium (Cd) ranged from uncontaminated to moderately contaminated (Class 0 to 2) for LL, HL, and NA. Overall, trace element levels were categorized as unpolluted based on PLI. Soil properties significantly correlated with Cu, Pb, Ni, and Zn concentrations but not with Cd. Based on PCA, sources of origin for Cu, Pb, Ni, and Zn were lithogenic, while the sources for Cd was anthropogenic in the studied agricultural soils.     

农田土壤重金属污染的农业生态修复技术

总结了常见的农田土壤重金属污染的农业生态修复技术,包括合理施用化肥、施用生物有机肥、秸秆还田、调整作物种植结构、筛选重金属低积累作物品种和耐性作物品种、深耕深翻、控制土壤水分以及施用石灰等修复措施,并对农田土壤重金属污染修复技术的前景进行了展望。     

我国城市土壤重金属污染研究现状和展望

随着我国城市化和工业化的高速发展,城市土壤重金属污染越来越受到关注,本文在文献调研的基础上,比较国内主要城市土壤重金属污染的含量水平,综述了我国城市土壤重金属污染来源、化学形态、分布特点、生态效应等,并提出了研究展望,以期为相关研究、环境决策和环境管理提供参考。     

Potential Groundwater Contamination with Toxic Metals in and Around an Abandoned Zn Mine, Korea

This study evaluated potential groundwater contamination with toxic metals in and around an abandoned zinc mine in Korea. Water levels in the mine waste dump indicated occurrence of a losing stream during the period of peak stream flow as a result of snowmelt runoff, which posed the threat of groundwater pollution. The pH values for the groundwaters were near neutral to slightly basic, with a slight increase of the values along the stream flow direction. Higher values of electrical conductivity were observed in the mine area. High dissolved oxygen concentrations clearly indicated an oxygenated groundwater environment. High concentration of sulfate and most dominant Ca-SO₄ type groundwaters represent effects of mine drainage and sulfide minerals. In the mine area, groundwater contamination by Zn, Al, Fe, and Mn was observed. Most of the toxic metals decreased with distance from the mine, some have decreased gradually or others more suddenly although some metals were also found in high concentrations- in downgradient area. Levels of toxic metals were relatively low in groundwaters downgradient of the mine, which may be due to the high pH and highly oxygenated conditions, and mixing with metal-free waters.     

Metal Concentrations in Organs of the Clam Amiantis umbonella and Their Use in Monitoring Metal Contamination of Coastal Sediments

The aim of this study was to evaluate the use of metal concentrations in clam organs to monitor metal contamination in coastal sediments. The concentrations of Cd, Cr, Cu, Hg, Ni, Pb, V, and Zn were measured in the kidneys, gonads, mantles, gills, digestive gland, and hearts of the infaunal clam Amiantis umbonella collected from a contaminated site near desalination and power plant discharges, and a reference site in Kuwait Bay. Metal concentrations in sediment and sediment pore water were also measured at the collection sites of individual clams at the contaminated site. The concentrations of all metals in all organs (except Zn in the digestive gland) were significantly higher in clams from the contaminated site than from the reference site. Metal concentrations in several organs in A. umbonella from the contaminated site were correlated with those in the sediments and pore waters to which they were exposed. However, fresh weights of gonads, gills, and mantles were significantly lower in clams from the contaminated site compared to the reference site, indicating that the observed elevated concentrations of metals in the organs of clams from the contaminated site largely reflect lower organ weights, rather than higher metal loads, and that these organs in A. umbonella and perhaps other clams are not appropriate for use as biomonitors of metal contamination. Metal concentrations in clam kidneys showed a wide dynamic range with respect to environmental contamination and kidney weight was not variable. Therefore, metal concentrations in clam kidneys provide a reliable biomonitor of contaminant metals in coastal marine sediments.     

Using Factor Analysis to Characterise Historical Trends of Trace Metal Contamination in a Sediment Core from the Tagus Prodelta,Portugal

Water, Air, & Soil Pollution - It is well established that the livestock sector is a major contributor to greenhouse gases (GHG) and ammonia (NH3) emissions. In this paper, the evolution of...     

长江三角洲地区土壤重金属污染的防治与调控

简要介绍了长江三角洲地区土壤重金属污染现状与特点及其成因,在此基础上提出了长江三角洲土壤重金属污染防范措施和2种不同类型的治理与调控措施。针对典型污染源引起的局部重度重金属污染土壤,宜使用工程修复与植物修复及其联用技术进行调控。针对农业和交通运输业引起的大面积轻度重金属污染土壤,宜从提高土壤自净能力的角度,运用环境矿物修复和农业生态措施进行调控。继而,进一步提出了今后长江三角洲地区土壤重金属污染防治与调控的主要研究方向。     

湘中地区发育于黑色页岩上的土壤重金属污染特征

对湘中地区的安化、桃江、宁乡系统采集了黑色页岩土壤及其相应的黑色页岩样品,并运用ICP-MS对样品进行微量元素和重金属分析。结果表明:在黑色页岩及其风化形成的土壤样品中,Cr、Cu、U、Mo、Sn、Sb、Tl、Ba等重金属元素都呈明显的富集状态;同时,土壤与母岩的稀土元素在陨石粒径标准化后均表现为相同的右倾型分配模式。运用富集指数法对该区黑色页岩土壤进行评价,发现湘中地区黑色页岩发育的土壤都不同程度地受到了重金属的复合污染,且以桃江的污染最为严重;地质累积指数分析结果进一步表明,黑色页岩土壤中普遍受污染的元素主要有Cr、U、Mo、Sb、Ba等。土壤中重金属元素的污染程度排序为:安化:Sb>Ba>Mo>Co=Cu=U;桃江:Sb>Pb>V=Mn=Co=Cu=U=Mo=Ba>Cr=Cd;宁乡:Mo=U=Sb=Ba>Th。     

西北部分矿区豆科植物根瘤菌重金属抗性及16S rDNA RFLP分析

从生长在西北部分矿区的豆科植物根瘤中分离筛选到对重金属有抗性的38株根瘤菌,采用PCR-RFLP分子技术进行16S rDNA指纹图谱分析,选取每种类型的代表菌株进行16S rDNA全序列测定,建立系统发育树状图,并对38株菌进行Zn、Hg、Cu、Cd和Pb5种重金属的抗性研究。结果表明,供试菌株分别归属于中华根瘤菌属（Sinorhizobium）、根瘤菌属（Rhizobium）和土壤杆菌属（Agrobacterium）。代表菌株CCNWSX1277和CCNWSX1294可耐受2.0mmol·L-1的Zn2＋,CCNWSX1277可耐受0.25mmol·L-1的Hg2＋,多数代表菌株可耐受1.6mmol·L-1的Cu2＋,仅3株代表菌株可以耐受Cd2＋,其中CCNWSX1277能耐受1.4mmol·L-1的Cd2＋,所有代表菌株能耐受2.5mmol·L-1的Pb2＋。Agrobacterium属的2株代表菌株对5种重金属均有较强的耐受性;而Rhizobium属的4株菌和Sinorhizobium属的3株菌对5种重金属的耐受性不同,表现出较大的差异。总体来看,供试菌株对重金属的耐受性顺序为Agrobacterium〉Rhizobium〉Sinorhizobium。     

Heavy Metal Contamination of Soil and Vegetation in the Vicinity of Industries in Bangladesh

Water, Air, &; Soil Pollution - A study was conducted to investigate the heavy metal contamination of soil and vegetation in the vicinity of industries around Dhaka city in Bangladesh....     

城乡交错带河流表层沉积物重金属污染及潜在生态风险评价

针对城乡交错带河流表层沉积物重金属污染问题,以成都市江安河为例进行污染分析和潜在生态风险评价。选取何家湾、马家市、金花桥、凉港大桥4个断面进行沉积物取样,测定其Cu、Pb、Cr、Ni、Mn、Zn、Cd共7种重金属元素的含量,并采用地积累指数法和Hakanson指数法进行重金属污染级数分析及潜在生态风险评价。研究表明:何家湾受到Zn中度污染,马家市、金花桥、凉港大桥受到Zn轻度污染,何家湾、金花桥和凉港大桥受到Cu和Cr轻度污染。潜在生态风险指数由大到小为何家湾 > 凉港大桥 > 金花桥 > 马家市,均小于40,属轻微生态风险。城市化所带来的重金属污染初见端倪,污染分布和生态风险与沿岸工农业生产分布和城市化进程相关。城乡交错带在城市化进程中应开展环境整治并加强环境管理。     

绥满公路路侧典型植被区土壤重金属污染特征及评价研究

以绥满公路(301国道)黑龙江境内海林至亚布力段为研究区,对公路沿线三种典型植被下,距公路不同距离的297个样点表层土壤(0～20cm)中Pb、Cd、Cu、Zn、As元素含量的分析。结果表明,所调查公路旁侧土壤重金属平均含量与背景值相比,5种金属含量普遍较高,但三种不同类型植被土壤重金属平均含量无显著差异。各种类型土壤的单因子和综合污染指数计算数据显示,Cd类型Ⅰ为重污染,类型Ⅱ和类型Ⅲ为中度污染,Zn、Cu、Pb、As轻度污染,综合污染指数等级均达到中度污染。相关性分析结果显示公路建设营运是造成公路路侧土壤Pb、Cd、Cu等重金属污染的主要原因。复层结构的林带土壤主要污染区距公路约40～60m范围之内,纯乔木组成的林带土壤主要污染区距公路约70～100m范围之内,农田土壤主要污染区距公路约70～100m范围之内。复层结构的林带能阻止重金属污染物向更远处扩散,能缩小公路污染影响范围,纯乔木组成的林带阻止重金属污染物扩散效果不明显。     

Heavy Metals Contamination in Vegetables Grown in Urban and Metal Smelter Contaminated Sites in Australia

Dietary exposure to heavy metals, namely cadmium (Cd), lead (Pb), zinc (Zn) and copper (Cu), has been identified as a risk to human health through the consumption of vegetable crops. This study investigates the source and magnitude of heavy metal contamination in soil and vegetable samples at 46 sites across four vegetable growing regions in New South Wales, Australia. The four regions Boolaroo, Port Kembla, Cowra and the Sydney Basin were a mix of commercial and residential vegetable growing areas. The extent of metal contamination in soils sampled was greatest in regions located in the vicinity of smelters, such as in Boolaroo and Port Kembla. Soil metal concentrations decreased with depth at these two sites, suggesting contamination due to anthropogenic activities. Cadmium, Pb and Zn contamination was greatest in vegetables from Boolaroo, and Cu concentrations were greatest in vegetables sampled from Port Kembla. At Boolaroo, nearly all the samples exceeded the Australian Food Standards maximum level (ML) (0.01 mg kg^?1 fresh weight) of Cd and Pb in vegetables. Over 63% of samples exceeded international food standard guidelines set by the Commission of the European Communities and the Codex Alimentarius Commission. All vegetables sampled from Cowra, which is a relatively pristine site had Cd and Pb levels below the Australian and international food standards guideline values. This study suggests that the Australian guideline values are more conservative in defining the ML for Cd and Pb in vegetable crops. This investigation highlights the increased danger of growing vegetables in the vicinity of smelters.     

淮南粉煤灰处置场周围土壤中若干金属污染调查

通过系统采集高皇和上窑两个贮灰场周围土壤样品,采用ICP-AES分析方法,调查土壤中若干金属元素(Cd、Cr、Cu、Mn、Ni、Pb、Zn)含量,评价淮南市三大热电厂大体积粉煤灰长期处置导致土壤金属污染状况。结果表明:这些元素在土壤中表现积累性富集,Cu、Cd、Cr具有相对高的迁移性。但土壤金属含量除Cu外,均没有超过国家土壤一级质量标准,土壤属无污染或轻微污染类型。因此,有效处置管理措施能够控制淮南粉煤灰中有害金属的环境影响。