珠江三角洲养殖鱼塘水体中重金属污染特征和评估

为了解珠江三角洲主要养殖环境中重金属含量及潜在生态危害程度,用电感藕合等离子质谱法和原子荧光法测定了肇庆、广州、惠州和茂名4市14个样点沉积物中7种元素的水体及底泥总量,并对底泥中主要重金属污染状况及潜在生态风险进行了评价。结果表明：养殖鱼塘水体中Cr质量浓度范围是nd-0.1011 mg·L-1,超标率为7.1%,Cu质量浓度范围为nd-0.1438 mg·L-1,超标率为64.3%,As质量浓度范围是0.0112-0.0812 mg·L-1,超标率为24.1%,Hg质量浓度范围是0.00004-0.00458 mg·L^-1,超标率为35.7%,Pb质量浓度范围为nd-0.0973 mg·L^-1,超标率为6.8%,其余Ni、Zn和Cd质量浓度范围分别为nd-0.0218、nd-0.0232和nd-0.00319 mg·L^-1,均未超渔业水质标准;底泥中重金属元素Cr、Cu、Zn、As、Hg、Cd和Pb的平均值分别为83.86、46.19、242.16、32.38、0.64、1.00和60.06 mg·kg^-1,地积累指数评价结果显示,表层沉积物重金属污染程度顺序为Cd＞Hg＞Zn＞Pb＞As＞Cu＞Cr,其中,Cd污染程度为中-强,是底泥污染最严重的元素。潜在生态风险指数分析,单项潜在生态风险指数生态风险均值排列顺序为 Hg＞As＞Cd＞Pb＞Cu＞Zn＞Cr。对区域综合潜在生态风险指数RI的贡献率最大的元素为Hg、As和Cd。4个市底泥潜在生态风险综合指数（RI）比较,惠州（290.13）＞广州（240.54）＞茂名（193.23）＞肇庆（116.40）。Hg和Cd是该水域污染和潜在生态风险最大的元素。     

Assessment of As and Heavy Metal Contamination in the Vicinity of Duckum Au-Ag Mine, Korea

In order to assess the potential of As and heavy metal contamination derived from past mining activity and to estimate the human bioavailability quotients for As and heavy metals. Tailings, soils and crop samples were collected and analysed for As, Cd, Cu, Pb and Zn. The mean concentrations of As, Cd, Cu, Pb and Zn in the tailings were 68.5, 7.8, 99, 3,754 and 733 µg g^–1, respectively. Maximum Pb concentration in tailings was up to 90 times higher than its tolerable level. The concentrations of these metals were highest in the soils from the dressing plant area, and decreased in the order: farmland soil to paddy soil. In particular, some of the soils from the dressing plant area contained more than 1% of Pb and Zn. The pollution index ranged from 0.19 to 1.93 in paddy soils, and from 1.47 to 3.60 in farmland soils. The average concentrations of heavy metals in crops collected from farmland were higher than those in rice stalks or rice grains, and higher than the internationally accepted limits for vegetables. Element concentrations extracted from farmland soils within the simulated human stomach for 1 h are 9.4 mg kg^–1 As, 3.8 mg kg^–1 Cd, 37 mg kg^–1 Cu, 250 mg kg^–1 Pb and 301 mg kg^–1 Zn. In particular, the extracted concentrations of Cd, Pb and Zn are in excess of the tolerable levels. The results of the simple bioavailability extraction test (SBET) indicate that regular ingestion (by inhalation and from dirty hands) of soils by the local population could pose a potential health threat due to long-term toxic element exposure.     

江苏南通表土、地面灰重金属污染及潜在生态风险评价

选取南通市不同功能区表土、地面灰为对象,测试重金属元素Pb、Zn、Cu、Ni、Cr含量,并评价重金属污染水平和潜在生态风险程度.结果表明,表土、地面灰中Pb、Zn、Cu含量较高,污染较为严重,Ni、Cr含量较低,污染较轻.重金属污染顺序为工业区〉商业区〉交通区〉文教区〉住宅区.表土与地面灰重金属物质来源相似,一部分主要来自地壳物质,一部分受人为污染干扰.地面灰的重金属污染水平及潜在风险程度均高于表土,且崇川区工业区、商业区潜在生态风险程度较高,其余地区潜在生态风险程度较低.该项研究可为重金属污染防治提供科学参考.     

镍钴采选行业废石和尾矿中重金属淋溶释放规律研究

镍钴采选废石和尾矿中重金属的溶出释放规律对矿区的重金属污染防治具有重要意义。但目前,国内还没有对镍钴行业采选产生的尾矿和废石中重金属的溶出规律开展研究。本文以镍钴采选企业的尾矿和废石作为样本,开展了毒性浸出实验。研究了不同pH值、离子强度、温度等实验条件对重金属溶出的影响,探讨了镍钴采选过程中所产生的尾矿和废石中重金属的溶出特性和释放规律。实验结果表明,尾矿样品中Ni的浸出浓度为42.28 mg·L^-1,是最大允许排放浓度的8.86倍,为具有浸出毒性特征的危险废物;废石样品中重金属Ni和Cu的溶出浓度分别为4.72 mg·L^-1和26.2 mg·L^-1,超过最大允许排放浓度,属于第Ⅱ类一般工业固体废物。pH对样品中Ni、Cr、Pb、Co和As的溶出量影响较大,其中尾矿中Ni和Cu在pH较低的条件下,可达到44.28 mg·L^-1和53 mg·L^-1,远高于最大允许排放浓度,而Hg、Cd和Cu的溶出量随pH值的变化不大。除As以外,样品中大多数重金属的溶出质量浓度在酸性条件下比在中性条件下高,这表明在酸性环境条件下,这些重金属对周围生态环境的潜在风险更大。离子强度的变化对Cd和Co的溶出量的变化并不明显,而当离子强度变化时,Ni、Cr、Pb、Hg、Cu和As的溶出量可能达到最大,使周围环境的潜在生态风险增大。当温度达到35~40℃时,部分重金属如Co、Pb、Cd 等,溶出量将达到最大;当温度低于25℃时,除 Ni 以外,大部分重金属溶出量很低。而温度变化对重金属Cu、As、Cr和Hg的溶出量的影响不明显,波动范围较小,对周围生态环境产生的潜在生态风险较小。     

Investigation and risk assessment modeling of As and other heavy metals contamination around five abandoned metal mines in Korea

Tailings, agricultural soils, vegetables and groundwater samples were collected from abandoned metal mines (Duckum, Dongil, Dongjung, Myoungbong and Songchun mines) in Korea. Total concentrations of arsenic (As) and heavy metals (Cd, Cu, Pb and Zn) were analyzed to investigate the contamination level. Several digestion methods (Toxicity characteristics leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP), 0.1 N/1 N HCl) and sequential extraction analysis for mine tailings were conducted to examine the potential leachability of As and heavy metals from the tailings. The order of urgent remediation for the studied mines based on the risk assessment and remedial goals was suggested. The Songchun mine tailings were most severely contaminated by As and heavy metals. Total concentrations of As and Pb in the tailings were 38,600–58,700 mg/kg (av. 47,400 mg/kg) and 11,800–16,800 mg/kg (av. 14,600 mg/kg), respectively. Agricultural soils having high As concentrations were found at the all mines. Average concentrations of Cd in the vegetables exceeded the normal value at all mines areas, while As only at the Dongjung, Myoungbong, and Songchun mine area. One groundwater sample each from the Dongil and Myoungbong mines, and 4 groundwater samples from the Songchun mine had values above 10 μg/L of As concentration. The TCLP method revealed that only Pb in the Songchun tailings, 6.49 mg/L, exceeded the regulatory level (5 mg/L). Employing the 1-N HCl digestion method, the concentration of As in the Songchun mine tailings, 4,250 mg/kg, was up to 3,000 times higher than its Korean countermeasure standard. Results from the sequential extraction of As in the tailings showed that the easily releasable fraction in the Myoungbong and Songchun mine tailings was more than 30% and the residual fraction was less than 40%. Based on results showing the exposure health risk employing the hazard quotient and cancer risk of As, Cd and Zn, the Dongil mine needs the most urgent remedial action. The concentration reduction factor (CRF) of As in both soil and groundwater follows the order: Songchun>Dongjung>Dongil>Myoungbong>Duckum mine.     

Assessment of heavy metals in water,sediment, Anabas testudineus and Eichhornia crassipes in a former mining pond in Perak,Malaysia

The concentrations of Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sn and Zn were analysed in water, sediment, muscle of climbing perch fish (Anabas testudineus), and tissue of water hyacinth plants (Eichhornia crassipes) collected from a former tin-mining pond in Perak, Malaysia. The monitoring was performed during the minimum and maximum rainfall periods. The concentrations of As, Cr, Fe, Ni, Pb and Zn in water exceeded the permissible limits set by the Interim National Water Quality Standards for Malaysia (INWQS). The risk index (RI) values determined for As, Cd, Cr, Cu, Hg, Pb and Zn in sediment presented a low degree of ecological risk. The order of the top three heavy metals measured in fish muscle was Zn?>?Fe?>?Al. The estimated daily intake (EDI) of As and Cr exceeded the allowable limits in both rainfall periods. The bioconcentration factor (BCF) and translocation factor (TF) values of Zn in water hyacinth were 24.865 and 3.214, respectively. The concentrations of Cu and Zn in the plant tissue were significantly correlated (p?<?.05) with the concentrations of heavy metals in water. Overall, climbing perch and water hyacinth are excellent bioindicators of environmental impacts on water bodies.     

芜湖市龙窝湖湿地土壤重金属污染特征及潜在生态风险评价

分析了不同人类活动方式下芜湖市龙窝湖湿地土壤镍（Ni）、铬（Cr）、镉（Cd）、铅（Pb）、铜（Cu）和锌（Zn）含量差异,采用污染指数法、潜在生态风险指数法和沉积物质量基准（SQG）比较法对湿地土壤重金属污染特征和潜在生态风险进行评价。结果表明：6个样地土壤重金属含量只有Cd含量（0．76—3．67mg／kg）显著超过土壤环境质量二级标准（GB15618—1995）;6个样地土壤Cd和Cu含量与塘式水产养殖湿地、网式水产养殖湿地、垃圾倾倒地下游湿地和垃圾倾倒地土壤Pb和Zn含量超过土壤背景值,而6个样地土壤Ni和Cr含量与湖泊底泥和耕地土壤Ph和Zn含量未超标;土壤6种重金属综合污染指数为垃圾倾倒地下游湿地（25．4）〉网式水产养殖湿地（25．3）〉塘式水产养殖湿地（23．1）〉垃圾倾倒地（19．2）〉耕地（8．2）=湖泊底泥（8．2）;土壤6种重金属综合潜在生态风险指数为网式水产养殖湿地（603．6）〉垃圾倾倒地下游湿地（595．5）〉塘式水产养殖湿地（538．4）〉垃圾倾倒地（439．9）〉耕地（145．6）〉湖泊底泥（136．6）。土壤cd含量高是导致湿地土壤重金属较高污染（Cd单项污染指数占综合污染指数：49％～76％）和存在严重潜在生态风险（Cd单项潜在生态风险指数占综合潜在生态风险指数：88％～96％）的关键元素。基于沉积物质量基准比较法的潜在风险评价结果表明湿地土壤存在M、Cd和Cu污染的中等潜在生态风险。     

Electro-remediation of tailings from a multi-metal sulphide mine: comparing removal efficiencies of Pb,Zn, Cu and Cd

Sulphidic mine tailings characterised by high concentrations of heavy metals (Pb 3532?±?97?mg/kg, Zn 8450?±?154?mg/kg, Cu 239?±?18?mg/kg and Cd 14.1?±?0.3?mg/kg) and abundant carbonate (17%) were subjected to eight lab-scale electrodialytic remediation (EDR) experiments to investigate the influence of current density, treatment time and particle size on removal efficiency. Pb and Cu removal improved when increasing current density, while Zn and Cd removal did not. In contrast Zn and Cd removal improved by grinding the tailings, while Pb and Cu removal did not. At the highest current density (1.2?mA/cm²), 94%, 75%, 71% and 67% removal of Pb, Zn, Cu and Cd could be achieved, respectively, on grinded tailings in 28 days. Sequential chemical extraction made before and after EDR revealed larger oxidisable fractions of Zn, Cu and Cd, representing large fractions of sulphides, which was likely to be the main barrier to be removed as efficiently as Pb. This was in accordance with acid/base extraction tests in which Pb showed high solubility at both high and low pH (up to 65% and 86% of extraction, respectively), while considerable extraction of Zn (55%) happened only at low pH; and very limited extraction (<20%) of Cu and Cd occurred at any pH.     

典型铜尾矿库周边土壤重金属复合污染特征

应用了Hakanson潜在生态风险指数法、相关分析法、主成分分析法对德兴铜矿尾砂库周边土壤Cu、Zn、Ni、Pb、Cr和Cd复合污染特征进行研究,定量确定了铜尾矿库潜在生态风险程度、主要污染因子和潜在生态风险因子。结果表明:铜矿尾矿库周边土壤受到不同程度的重金属污染,该地区平均潜在生态风险污染指数超过600,具有极高的潜在生态风险;各重金属潜在生态风险参数由高至低顺序为Cd、Cu、Pb、Ni、Cr、Zn,其中Cd为主要潜在生态风险因子。进一步通过主成分分析法研究了重金属的污染特性,发现前3个主成分贡献率分别为:65.033%、18.825%、6.243%,第一主成分反映了Zn、Ni、Cr的信息,第二主成分反映了Cu和Cd的信息,第三主成分反映Pb的信息。     

Relative extraction ratio (RER) for arsenic and heavy metals in soils and tailings from various metal mines, Korea

This study focused on the evaluation of leaching behaviours for arsenic and heavy metals (Cd, Cu, Ni, Pb and Zn) in soils and tailings contaminated by mining activities. Ten representative mine soils were taken at four representative metal mines in Korea. To evaluate the leaching characteristics of the samples, eight extraction methods were adapted namely 0.1?M HCl, 0.5?M HCl, 1.0?M HCl, 3.0?M HCl, Korean Standard Leaching Procedure for waste materials (KSLP), Synthetic Precipitation Leaching Procedure (SPLP), Toxicity Characteristic Leaching Procedure (TCLP) and aqua regia extraction (AR) methods. In order to compare element concentrations as extraction methods, relative extraction ratios (RERs, %), defined as element concentration extracted by the individual leaching method divided by that extracted by aqua regia based on USEPA method 3050B, were calculated. Although the RER values can vary upon sample types and elements, they increase with increasing ionic strength of each extracting solution. Thus, the RER for arsenic and heavy metals in the samples increased in the order of KSLP?相似文献   

典型铜尾矿库周边土壤重金属复合污染特征

应用了Hakanson潜在生态风险指数法、相关分析法、主成分分析法对德兴铜矿尾砂库周边土壤Cu、Zn、Ni、Pb、Cr和Cd复合污染特征进行研究,定量确定了铜尾矿库潜在生态风险程度、主要污染因子和潜在生态风险因子。结果表明：铜矿尾矿库周边土壤受到不同程度的重金属污染,该地区平均潜在生态风险污染指数超过600,具有极高的潜在生态风险;各重金属潜在生态风险参数由高至低顺序为Cd、Cu、Pb、Ni、Cr、Zn,其中Cd为主要潜在生态风险因子。进一步通过主成分分析法研究了重金属的污染特性,发现前3个主成分贡献率分别为：65．033％、18．825％、6．243％,第一主成分反映了Zn、Ni、cr的信息,第二主成分反映了Cu和Cd的信息,第三主成分反映Pb的信息。     

Level,pattern, and risk assessment of the selected soil trace metals in the calcareous-cultivated Vertisols

Dynamics and distribution pattern of trace metals in agricultural lands are an increasing concern due to potential risks to the environment and human health. To ascertain more knowledge of this aspect, the fractions of total and available Fe, Mn, Zn, Cu, and Cd belonging to Vertisols under intensive cultivation and adjoining uncultivated soils were investigated. The order of abundance of metals in both cultivated and uncultivated soils was Fe?>?Mn?>?Cu?>?Zn?>?Cd and Fe?>?Mn?>?Zn?>?Cu?>?Cd for both available and total fraction, respectively. A relative enrichment was observed in the value of diethylene-triamine pentaacetic acid-extractable Fe (1.2–201%), Mn (2–31%), Cu (1–40%), and Cd (21–45%) as well as total fraction of Zn (3–17%), Cu (12–32%), and Cd (42–108%) after intensive cropping, which can be contributed to repeated application of agrochemical inputs and manure over long time. The values of RI (potential ecological risk) showed that cultivation caused a low potential ecological risk (33.3% of the soil samples) to moderate potential ecological risk (66.7% of the soil samples) in the study region and that cadmium made up 88%, on average, of the RI value.     

Chemical speciation and potential ecological risk assessment of heavy metals in volcanic rocks of Southern Qinghai,China

ABSTRACT

Seven volcanic rocks samples were collected from Southern Qinghai to analyze chemical speciation and migration behavior of heavy metals by sequential chemical extraction procedure and column leaching test. The geo-accumulation index, ecological risk index and the risk assessment code were applied to assess the heavy metal pollution and potential environmental effects in this area. Results revealed that the total concentrations of heavy metals did not exceed the background values in soil of this area. Most of the samples produced acid rock drainage. The order of heavy metal migration and transformation sequence in the volcanic rocks of Zhiduo region was Cd?>?Pb?>?As?=?Cu?=?Zn?=?Mn based on the geo-accumulation index and Cd caused heavy pollution, which was also confirmed by the leaching test. Moderate potential ecological risk posed by heavy metals occurred in the study area based on the potential ecological risk index. Cd contributed to most of ecological risk while the remaining heavy metals (except As) exerted medium to high risks to the environment according to the risk assessment code evaluation results. In summary, volcanic rocks possessed potential risks to the surroundings due to potential release of heavy metals. Cd that caused the pollution should be paid special attention.     

韶关矿产资源开采地区土壤生态系统的微生物生态效应研究

韶关地区大宝山铁多金属矿产资源的开采给环境带来了严重的危害。采选冶产生的废液及固体废弃物堆积的淋滤酸水,携带浸滤出的大量重金属离子排入下游河道,严重影响矿区及酸水流域的生态环境。通过对该铅锌矿区土壤重金属分布、土壤微生物数量与植物重金属积累特征进行采样分析研究,结果表明：铅锌矿区土壤各重金属元素质量分数均高于对照土壤,矿区土壤均受到不同程度的污染;五节芒（Miscanthusfloridulus）植物中的元素质量分数表现为Zn〉Pb〉Cu〉Cd,Zn与土壤元素的相关性最为显著,其次为Pb;与对照土壤相比,矿区土壤微生物总数下降了68．43％-80．32％,各主要生理类群数量均呈下降趋势。矿区土壤生态系统处于不利于有益微生物的繁殖和活动的境地,从而大大削弱了土壤中C、N营养元素循环速率和能量流动。     

开阳磷矿10种木本植物叶片重金属富集特征

植物对重金属具有一定的吸附能力,植物修复是生态修复不可或缺的一部分,利用植物减缓和治理重金属污染具有重要意义.选取开阳磷矿马路坪矿区生命周期较长的木本植物及其土壤作为研究对象,探究木本植物受Cu、Zn、Pb、Cd、As等5种重金属污染土壤的效应,对植物重金属含量及其富集特性进行研究分析,筛选出累积重金属的植物,作为矿区...     

淮南市城区地表灰尘重金属分布特征及生态风险评价

城市地表灰尘中重金属会对人体健康和生态环境产生危害,为研究城市中不同功能区地表灰尘重金属的含量和潜在生态危害水平,以典型煤炭资源型城市淮南市的地表灰尘为研究对象,采集工业区、商业区、交通区、文教区、居住区和公园绿地等6种功能用地共40个点位的地表灰尘。采用电感耦合等离子体发射光谱（ICP-OES）和DMA-80直接测汞仪测定Zn、Pb、Cu、Cr、Cd、Ni、Co、V、Hg的含量,分析其在不同功能区地表灰尘中的分布特征、相关性及可能的来源;并应用潜在生态危害指数法对重金属在不同功能区的潜在生态危害进行评价。结果表明：1）淮南市地表灰尘中 Zn、Pb、Cu、Cr、Cd、Ni、Co、V、Hg的平均质量分数分别是202.59、74.63、62.74、110.69、0.57、35.82、12.18、50.95和0.105 mg·kg-1,其中Zn、Pb、Cu、Cr、Cd、Ni、Hg的平均含量分别是淮南市土壤背景值的3.47、3.17、2.04、1.21、9.50、1.12、2.56倍,是中国土壤背景值的2.73、2.87、2.78、1.81、5.88、1.33、1.62倍。2）9种重金属中,Zn和V的含量在不同功能区分布相对均匀,其他重金属在不同功能区含量均表现出较明显的空间异质性。3）不同功能区中,Zn、Pb、Cu、Ni、Co、V、Hg的平均含量在工业区最高,Cr 和 Cd 的平均含量在交通区最高。4）不同重金属的相关性表明,Zn、Pb、Cu、Cd、Ni 等5种元素有同一来源,Co 和 V 有同一来源。5）单项潜在生态危害系数大小为 Cd〉Hg〉〉Pb〉Cu〉Ni〉Co〉Zn〉Cr〉V。不同功能区9种重金属复合生态危害均处于强生态危害水平（300≤RI〈600）,其中工业区和交通区潜在生态危害水平最高。     

珠海近岸海域表层沉积物中的重金属及生态危害评价

为了研究珠江口近海海域重金属的污染状况,2009年8—12月对珠海珠江口4个站点的表层沉积物进行了6次采样,测定了表层沉积物中重金属Cd、Cr、Pb、Hg、Cu、Zn、Mn、Ni、Fe和金属Al的质量分数,分析了它们质量分数间的相关性,依据Lars Hakanson提出的沉积物中金属污染物评价方法,对Cd、Cr、Pb、Hg、Cu和Zn等6种典型重金属的潜在危害进行了评价。结果表明,Cd、Cu和Zn是该调查区域的主要重金属污染物,应该予以优先控制和治理。位于马骝洲水道入海口的S1位点上,金属元素（Cd除外）质量分数的季节特征是秋季（丰水期）〈冬季（枯水期）,重金属危害指数（RT）为轻微级,重金属潜在生态危害系数（Eir）顺序为Cd〉Hg〉Pb〉Cu〉Zn〉Cr;在S2位点,Cd、Cu、Hg、Ni和Fe的平均质量分数为秋季〉冬季,其它5种金属则为秋季〈冬季,RT为强级;在S3、S4位点上,8种金属元素（Hg、Mn除外）的质量分数呈现秋季〉冬季的现象,RT为很强级;S2、S3和S4站点的Eir均表现为Cd〉Hg〉Cu〉Pb〉Zn〉Cr的顺序。     

典型野生食用菌重金属含量及其人体健康风险评价

土壤重金属污染是影响生态环境、食品安全和人体健康的重要因素.云南省土壤重金属背景值较高,且矿产资源丰富、采矿活动频繁,导致土壤重金属含量较高.野生食用菌是高效重金属储积器,云南是中国野生食用菌最大产区.因此,本文以云南省8种典型野生食用菌为研究对象,探究其重金属含量(汞、镉、铅、锌、铜、砷)与分配特征,采用单因子污染指数对其进行重金属污染评价,利用概率方法(THQ指数)评估其对不同年龄人群(成人、儿童)的人体健康风险.研究结果表明,不同种类野生食用菌重金属含量存在显著差异(P<0.05).Hg、Cd、Pb、Zn、Cu浓度范围分别为0.5—7.2、0.3—15、0—26.8、47.7—214、56.7—428 mg·kg^-1 dw;As未检出.此外,Hg、Cd、Pb、Zn、Cu均主要分布于菌盖.除虫草花、白森、干巴菌中Hg未检出,其余重金属污染评价中单因子污染指数均>1,且同一元素在同种野生食用菌不同部位污染程度不同,其中,老人头菌盖受Cd污染最为严重.基于国家食品安全标准,本研究中98%野生食用菌Hg、Cd、Pb含量超标.然而,THQ指数表明,部分野生食用菌中Zn无风险(THQ<1),老人头菌盖、鸡枞菌盖中Cd、Hg、Pb、Cu具有人体健康风险(THQ>1),且风险值儿童>成人.     

Impact of mining activities on soils in a semi-arid environment: Sierra Almagrera district, SE Spain

Field and laboratory-column studies were undertaken in order to investigate soil contamination derived from past mining activity in the Sierra Almagrera (SA) district in southeast Spain. The tailings, soil and sediment samples that were collected showed high concentrations of Ag, As, Ba, Cu, Pb, Sb and Zn when analyzed. The mean concentrations of these elements in the tailings were 29.8, 285.4, 54000, 57.7, 2687.5, 179.0 and 2269.0 ppm, respectively. In the soil samples these decreased to 14.3, 96.9, 24700, 37.5, 1859.1, 168.5 and 815.7 ppm, respectively. Geochemical analyses demonstrated high levels of As, Pb and Zn which were above the intervention values set forth in the Andalusian Regulations for Contaminated Soils for As (>50 ppm), Pb (>500 ppm) and Zn (>2000 ppm). Column experiments and mineralogical studies suggest that the dissolution of sulfates and other secondary phases, accumulated in soils and waste-sites during the dry season, acts to control the mobility of metals. The elution curves obtained from column experiments showed a mobilization of Ba, Cu, Pb and Zn, while a low mobility was seen for Ag, As and Sb.     

Impact of mining activities on soils in a semi-arid environment: Sierra Almagrera district, SE Spain

Field and laboratory-column studies were undertaken in order to investigate soil contamination derived from past mining activity in the Sierra Almagrera (SA) district in southeast Spain. The tailings, soil and sediment samples that were collected showed high concentrations of Ag, As, Ba, Cu, Pb, Sb and Zn when analyzed. The mean concentrations of these elements in the tailings were 29.8, 285.4, 54000, 57.7, 2687.5, 179.0 and 2269.0 ppm, respectively. In the soil samples these decreased to 14.3, 96.9, 24700, 37.5, 1859.1, 168.5 and 815.7 ppm, respectively. Geochemical analyses demonstrated high levels of As, Pb and Zn which were above the intervention values set forth in the Andalusian Regulations for Contaminated Soils for As (>50 ppm), Pb (>500 ppm) and Zn (>2000 ppm). Column experiments and mineralogical studies suggest that the dissolution of sulfates and other secondary phases, accumulated in soils and waste-sites during the dry season, acts to control the mobility of metals. The elution curves obtained from column experiments showed a mobilization of Ba, Cu, Pb and Zn, while a low mobility was seen for Ag, As and Sb.