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1.
Fourteen samples from the Haveri Au–Cu mine tailings were studied by reflected-light microcopy, scanning electron microscopy, X-ray powder-diffraction, and sequential extraction methods, and 12 water samples were analyzed for total and dissolved elements to delineate the extent of sulfide oxidation and its impact on nearby surface waters. Water-soluble, adsorbed-exchangeable-carbonate (AEC), Fe (oxy)hydroxides, Fe oxide, and Fe sulfide fractions were extracted sequentially. The oxidation layer was found to vary from 50 to 140 cm: the upper part was nearly depleted in primary sulfides, especially pyrrhotite [Fe(1?x)S] and pyrite (FeS2); in the lower part, discontinuous cemented layers were detected. Secondary Fe (oxy)hydroxides and Fe oxyhydroxysulfates were abundant in the oxidation layer and were slightly enriched in trace elements, including As (up to 80 mg/kg), Cu (300 mg/kg), and Zn (150 mg/kg). Almost half of the As (average 25 mg/kg) were present as secondary minerals susceptible to redissolution. The pH of the vadose tailings varied from 2.46 to neutral, and the total sulfur content varied from 1 to 6.5% (average 2.9%). Aqua regia extraction showed that the Haveri tailings are characterized by low concentrations of the elements Cd, Cr, Pd, and slightly elevated concentrations of As, which are present at very low concentrations in the surface water (<6 μg/L). However, runoff that flows on top of the tailings and discharges into the nearby lake carries Co, Cu, Ni, and Zn (concentrations of each range from 500 to 1,800 μg/L). Additionally, dissolution of sulfides and Fe precipitates may mobilize trace metals in the ground water. Thus, overall, there is a small continuous release of AMD into Lake Kirkkojärvi, but the environmental impacts to the lake are presently small.  相似文献   

2.
Steel slag from the Waylite steel-making plant in Bethlehem, Pennsylvania was leached with acidic mine drainage (AMD) of a known quality using an established laboratory procedure. Leaching continued for 60 cycles and leachates were collected after each cycle. Results indicated that the slag was very effective at neutralizing acidity. The AMD/slag leachates contained higher average concentrations of Ba, V, Mn, Cr, As, Ag, and Se and lower average concentrations of Sb, Fe, Zn, Be, Cd, Tl, Ni, Al, Cu, and Pb than the untreated AMD. Based on these tests, slag leach beds were constructed at the abandoned McCarty mine site in Preston County, West Virginia. The leach beds were constructed as slag check dams below limestone-lined settling basins. Acid water was captured in limestone channels and directed into basins to leach through the slag dams and discharge into a tributary of Beaver Creek. Since installation in October 2000, the system has been consistently producing net alkaline, pH 9 water. The treated water is still net alkaline and has a neutral pH after it encounters several other acidic seeps downstream.  相似文献   

3.
Acid mine drainages (AMD) have adversely affected the southern Apuan Alps (northern Tuscany, Italy). The study particularly focuses on the Baccatoio stream, which receives AMD from the abandoned Pollone and M. Arsiccio mines. The mine waters have an average pH of 2.2 and contain potentially toxic elements (PTE) at concentrations that exceed the Italian regulatory threshold for Al, Fe, Mn, Cu, Zn, As, Ni, Co, Cd, Sb, Pb, and Tl. The AMD flow directly into the stream, severely contaminating it. Downstream of the mined areas, the pH increases and most PTE (especially Fe, Al, As, and Pb) are readily scavenged from the stream waters by precipitation and/or adsorption. However, Tl, which peak at 1000 µg/L in the AMD, behaves almost conservatively along the stream flow path, undergoing only dilution, and remains at or above the concentration of concern of 4 µg/L almost to the coastline, before sharply decreasing to 0.5 µg/L where seawater is encountered. Since the stream water was locally used for irrigation, these observations may have important environmental and public health consequences in such a densely populated area.  相似文献   

4.
煤矿酸性矿井水中有害元素的迁移特性   总被引:7,自引:0,他引:7       下载免费PDF全文
利用电感耦合等离子质谱(ICP-MS)、离子色谱(IC)和X射线衍射(XRD)等方法研究了马兰煤矿酸性矿井水及其沉淀物的化学成分和物相组成,并通过吸附解吸实验和PHREEQC水化学模拟计算研究了典型酸性矿井水样品中Pb,Th,U,Be,Zn,Ni,Co,Cd,Cu,As,Cr,V,Ba等有害元素的迁移特性.研究表明:① 煤矿酸性矿井水中SO2-4,Fe,Mn,Al,Pb,Th,U,Be,Zn,Ni,Co,Cu等离子含量较高,对环境存在潜在危害;② 酸性矿井水中有害元素的迁移主要受pH,Fe-Al-Mn含量和水体颗粒物矿物组成的控制;③ Fe,Al和Mn的含量随pH上升而迅速下降,并控制着Pb,Th,U,Be,Zn,Ni,Co,Cu等潜在有害微量离子的迁移行为; ④ 各离子随pH上升被去除的先后顺序为: Th>Fe>Pb >Cr>Al>Cu>Be>U>Zn>As>Cd>Mn>Co>Ni>Ba;⑤ 酸性矿井水中V不能够随pH的升高而去除,反而会有更多的V溶解在水中.  相似文献   

5.
Acid mine drainage (AMD) and fly ash from thermal power plants both pose substantial environmental problems in India. Fly ash from the Talcher super thermal power plant was converted into zeolite and used in a column to treat AMD from the abandoned Gorbi opencast mines (Singrauli coalfields, NCL). The pH of the mine water increased, and 100 % of the total hardness, Ca hardness, Mg hardness, Mn, Zn, Pb, Cd, Ni, and acidity were removed, along with 99 % of the Fe and 90 % of the Cu.  相似文献   

6.
在收集整理高纬高寒地区某铜矿区以往监测资料和开展的动态监测研究的基础上,对近12年来研究区表层土壤重金属As、Cd、Cr、Cu、Hg、Mo、Ni、Pb和Zn的时空变异趋势进行对比分析,且定量计算了土壤重金属的累积速率。分析结果表明,堆浸场的Cd、Cu含量在尚未开始堆浸时就已超过国家土壤II级标准限值,年均增长速率又较快,因而此处土壤恶化的可能性较大,应引起足够的重视。而尾矿库和排土场处,除了Ni具有较高的超标风险外,其他元素的环境容量相对较大。堆浸场下游的表层土壤中Cr、Zn、Ni、Pb、Cr6+、Cd和Cu元素的横向迁移距离相对较短,而As、Hg和Mo元素横向迁移距离略长,更容易随堆浸液排放向下游运移。剖面土壤样品中Cu、Zn、Cr、Cd的含量随着深度的增加而降低,表土中重金属含量高于深层土壤样品,呈现出在冻土层的冻结锋面上富集的规律。   相似文献   

7.
The metal removal and neutralization capacities of digested sewage sludges from municipal wastewater treatment plants, cattle slurry (liquid manure), and Biofert granules (dried granular anaerobic sludge) were compared under batch conditions using synthetic AMD (pH 2.8) containing high concentrations of Al, Cu, Fe, Mn, Pb, and Zn (100, 15, 270, 15, 2, and 30 mg/L, respectively). The effects of contact time and solids concentration were examined. Metal removal was variable for all materials. Contact time had a significant effect, with total removal often increasing over the experimental time interval (i.e. 30 min to 24 h). Removal efficiency (%) was generally highest for Cu, Pb, and Al, while Mn and Zn were the least removed. Cattle slurry was the best material for metal removal, with the following maximum removals at a solids concentration of 12.9 g/L: Cu >98 %, Al >98 %, Fe >60 %, Mn >18 %, Pb >96 %, and Zn >60 %. Metal removal using digested sewage sludge reached 88 % for Al, 98 % for Cu, 94 % for Pb, and 30 % for Zn. Neutralization was complete within 30 min after AMD was mixed with digested sludges or cattle slurry, with the pH reaching a maximum of 5.5 with the slurry. In contrast, neutralization by the Biofert granules only reached equilibrium after 300 min, and pH remained <4.0 except at high solids concentrations. It appears that recycled waste-derived organic materials can neutralize AMD and remove dissolved metals by adsorption and precipitation, creating a more treatable waste stream or one that could be discharged directly to surface water. Potential methods of safe disposal of metal-enriched organic materials are discussed.  相似文献   

8.
泉州市主要工业区土壤重金属健康风险评价   总被引:7,自引:0,他引:7  
为了解泉州市工业区土壤重金属的污染程度,采用现场采样及室内测试方法对泉州市主要工业区土壤中Cd、As、Pb、Zn、Cu、Hg、Ni和Cr等重金属的含量进行测定分析,应用健康风险评价模型对这些工业区土壤重金属通过皮肤暴露途径所引起的健康风险作出评价.结果表明,工业区土壤已受到不同程度的重金属污染,其中以Zn、Cu、Pb污染最为严重.土壤重金属的含量空间分布并不均匀.土壤重金属非致病风险大小为:Pb> As> Cu> Cr> Cd> Zn> Hg> Ni,均小于致癌风险阚值1,对人体不会造成健康危害.致癌风险Cd> As,均低于致癌风险阈值,表明Cd和As不是主要的致癌风险因素.  相似文献   

9.
Opencast lignite mines, pit-head thermal power plants, and other associated industries in the Neyveli mining and industrial complex generate huge quantities of solid and liquid wastes that are contaminated with heavy metals. Some of these are toxic or carcinogenic at sufficient concentrations. Copper, Zn, Mn, Fe, Ni, Cd, Cr, Co, Pb, and Hg concentrations in surface water in the study area are from 2 to 1200 times higher than average concentrations in river water worldwide. Heavy metal contamination in the natural reservoirs (Peria, Kolakudi, Walaza, and Perumal Ponds, and the Paravannar River) is mainly due to the discharge of untreated mine water, fly-ash pond water, and effluents from associated industries. These waters have long been used for bathing, washing, animal watering, etc. Untreated mine and industrial waste water, and natural reservoir water have been used by nearby villagers for irrigation for the last four decades, which may have led to deterioration of soils, surface water, and groundwater. Heavy metal analyses of mine water, fly-ash pond and industrial effluents and the natural reservoirs reveals that Co, Cr, and Hg are above the recommended irrigation water quality standards in 17%, 75%, and 100% of the samples, respectively. Most samples were within the permissible limits for Mn, Ni, and Fe, while Pb, Zn, Cd, and Cu were within the limits in all samples. At elevated concentrations, toxic metals like Cr, Co, and Hg can accumulate in soils and enter the food chain, leading to serious health hazards and threatening the long-term sustainability of the local ecosystem.  相似文献   

10.
为探究某工业园周边农田土壤重金属污染及潜在风险状况,系统采集了园区周边农田15个表层土壤,通过测定土壤的pH及重金属Pb、Cu、Zn、Cd、Cr、Ni,并借助Pearson相关性分析和主成分分析等分析方法,及内梅罗指数法及Hakanson潜在风险评价指数法等评价方法,进一步揭示重金属的污染特征及潜在风险。研究结果表明:Pb、Cu、Zn和Cd的平均含量超过了我国农用地风险筛选值,Cd的平均含量甚至超过管制值,该地区土壤已不适合作为农用地用途;距离工业区较近的土壤中重金属浓度较高,研究区土壤中重金属污染来源与工业园关系密切;内梅罗综合指数污染法评价表明所有采样点的土壤均为重度污染,各金属元素的潜在风险指数从大到小依次为Cd>Pb>Cu>Ni>Cr>Zn,其中Cd是对潜在生态风险指数贡献最大的金属元素。人体健康风险评估表明,Pb、V和As对人体造成非致癌风险的很显著,As存在很大可能的致癌风险。周边工矿活动等人为活动对土壤的重金属贡献份额达71.99%,自然源贡献为17.06%。整体来看,研究区土壤呈现极高生态风险水平,应当对该区域土壤污染采取一定的调控措施。  相似文献   

11.
金矿区尾矿渣周边土壤的重金属污染评价研究   总被引:1,自引:0,他引:1       下载免费PDF全文
在小秦岭金矿区内选取姚青村、来福沟和毛沟三个具有代表性研究区,采集研究区内尾渣堆及渣堆周围农田样品30个,测定了重金属Cr、Ni、Cu、Cd、Zn、As、Pb含量。对土壤样品重金属测定结果分别采用地累积污染指数法和潜在生态危害指数评价法进行评价,结果显示:As不是矿业活动污染的典型金属;姚青村和来福沟重金属典型污染物为Cu、Zn、Cd、Pb。采用地累积污染指数法评价,姚青村和来福沟的Pb属于极严重污染,而Cr、Ni均属无污染。采用潜在生态危害指数法进行评价,毛沟研究区属轻微生态危害,姚青村和来福沟生态风险程度均属极强,贡献率大的元素主要为Pb和Cd。  相似文献   

12.
Laboratory and field treatment tests were performed to evaluate the effectiveness of lime treatment for mitigation of environmental effects of acid mine drainage (AMD) at the Sarcheshmeh porphyry copper mine. AMD associated with the rock waste dumps is contaminated with Al (>36,215 μg/L), Cd (>105 μg/L), Co (>522 μg/L), Cu (>53,250 μg/L), Mn (>42,365 μg/L), Ni (>629 μg/L), and Zn (>12,470 μg/L). The concentrations of other metals (Fe, Mo, Pb, and Se) are low or below detection limits (As, Cr, and Sb). Due to the very high Al and Mn content and the low concentration of Fe, a two-stage lime treatment method was chosen for the laboratory tests. In the first stage, the AMD was treated at four pH set points: 7.5, 8.9, 9, and 10. In the second stage, after removing the sludge at pH 9, treatment was continued at pH 10 and 11. The results indicated that a two-stage treatment method was not necessary because elements such as Al, Cu, Co, and Zn were easily treated at pH 7.5, while complete removal of Cd, Mn, and Ni only required a pH of 10. Increasing pH during the treatment process only caused a slight increase in Al. Field treatment tests support the laboratory results. Lime treatment of highly contaminated AMD from dump 11, using simple low density sludge pilot scale equipment, show that contaminant metals are treatable using this method. The mean treatment efficiency for contaminant metals was 99.4% for Al, % for Cd, 99.6% for Co, 99.7% for Cu, 98.5% for Mn, 99.7% for Ni, 99% for U, and 99.5% for Zn. The optimum pH for AMD treatment by lime was in the range of 9–10. The produced sludge in the treatment process was highly enriched in the contaminant metals, especially Cu (>7.34%), Al (>4.76%), Mn (>2.94%), and Zn (>1.25%). A correlation coefficient matrix indicates that the distribution pattern of the contaminant metals between soluble and precipitated phases is consistent with the hydrochemical behavior of the metals during the lime treatment process.  相似文献   

13.
马边老河坝磷矿资源丰富,矿业活动频繁,对矿区内水土环境影响不明。为查明老河坝磷矿区内矿山环境及水体、土壤内的重金属污染程度,以老河坝磷矿区水土环境为研究对象,对地表水及表层土壤的重金属元素(Cd、As、Cu、Cr、Pb、Zn)含量及其分布特征开展了生态污染程度评价。结果表明:研究区水质较好,重金属及磷元素污染程度较低,符合《地表水环境质量标准》(GB 3838—2002)Ⅲ类水质标准的相关指标。土壤中金属元素平均值与四川省土壤元素背景值相比:Cd元素超标8.75倍, Pb元素超标3.36倍, Zn元素超标1.94倍, As元素超标1.48倍, Cu元素超标1.36倍,P元素超标7.47倍。与中国土壤元素背景值相比:Cd元素超标10倍, Pb元素超标4.40倍, Zn元素超标2.48倍, As元素超标1.88倍, Cu 元素超标2.12倍,Cr元素超标1.42倍。潜在生态危害指数法显示,马边老河坝磷矿表层土壤重金属污染程度依次为Cd>As >Pb >Cu>Zn>Cr,Cd元素危害最大,其次是As、Pb和Zn,为中度生态污染风险。累积指数法显示,马边老河坝磷矿表层土壤重金属污染程度依次为Cd>Pb>As>Zn>Cu>Cr,Cd、Pb污染程度为中度。综上所述,马边老河坝磷矿重金属污染对水体影响小,而土壤重金属污染不可忽视。   相似文献   

14.
This paper presents chemical fractionation and contamination intensities of trace elements in stream sediments at the Sarcheshmeh mine, southeastern Iran, which is one of the world’s largest Oligo-Miocene porphyry copper deposits. Evaluation of environmental pollution indices and maximum probable background concentrations revealed that As, Cu, Cd, Mo, Pb, Sb, Se, S, and Zn are highly concentrated in the contaminated sediments, while Cr, Co, Ni, Fe, and Mn show lower enrichment values. Discharges of industrial effluents (especially those contaminated by tailings), reject waste from the semi-autogenous mill, and rock waste drainages are the main anthropogenic contaminant sources. High values of As, Cu, Fe, Mo, Pb, and Zn were associated with the oxidizable, primary sulfide, and residual sediment fractions. Relatively high percentages of Co (>92?%), Cr (>58?%), Cu (>79?%), Fe (>40?%), Mn (>97?%), Ni (>87?%), and Zn (>83?%) in the sediments associated with the rock waste drainages were readily released during the extraction of water-soluble, exchangeable, and carbonate fractions. Sediments that received reject waste drainages were also polluted by As (>351.7?mg?kg?1), Cu (>1.58?%), Mo (>91.8?mg?kg?1), Pb (>291.8?mg?kg?1), and Zn (>762.4?mg?kg?1). A large percentage of these contaminants were found to be adsorbed and co-precipitated with amorphous Fe-oxides and carbonate phases. The chemical fractionation pattern of the potentially hazardous trace elements corresponded well with the mineralogical composition of the contaminated sediments.  相似文献   

15.
以小秦岭金矿区内选矿厂尾渣堆为研究对象,采集尾渣堆积点及周边土壤样品36个,以土壤样品中的Cr、Cu、Zn、Ni、As作为研究对象,对不同采样点及剖面土壤Cr、Cu、Zn、Ni、As污染程度及相关性进行分析。采集土壤样品附近芦苇、花生、茵陈蒿等典型植物样品共计12份,测定Cr、Cu、Zn、Ni、As含量,并计算各植物样品的富集系数和转移系数,对植物富集特性进行综合评价。结果发现:距尾渣堆0~10 m范围内,Cu为重度污染,Zn为轻度污染。0~30 cm土壤剖面Cu和Zn含量表明,二者平均含量表现出20~30 cm>0~10 cm>10~20 cm的趋势。茵陈蒿对Cu、Zn的富集能力较强,可作为植物修复Cu、Zn污染的选择。  相似文献   

16.
为了研究矿区农田土壤-小麦中重金属分布及农作物中重金属的迁移特征,以皖北恒源煤矿为研究对象,在矿区范围内采集了16个农田土壤和对应的小麦样品进行测试分析,应用内梅罗指数法评价了矿区内农田土壤重金属的污染状况,采用回归模型分析研究土壤根系、根系茎籽粒中重金属的迁移转化,并利用靶标危害系数法评价了小麦籽粒中重金属对人身健康的影响。研究结果表明:研究区农田土壤中的Cu、Zn、Mn、Pb、Hg、Cd、As、Cr和Ni等8种重金属元素含量低;小麦籽粒中重金属含量也未超出标准限量值;在小麦根、茎、籽粒等器官中,Mn、Pb、Cd、As、Cr和Ni在小麦根部含量最大,Hg较多地分布在小麦的茎中,Zn和Cu更易向上迁移至小麦的籽粒中;小麦籽粒中的Pb、Hg、Cd、As和Cr等重金属的单一重金属元素的靶标危害系数THQ和多种重金属元素的复合危害系数TTHQ均小于1。  相似文献   

17.
Abstract  About 2.5 million t of sedimentary phosphorite mine tailings, highly enriched with trace metals such as Cd, Cr, Cu, Ni, and Zn, are dumped annually in the coastal waters of Togo without any pre-treatment, causing serious pollution problems in the region. We conducted laboratory jar tests of a coagulation-flocculation procedure with coagulants RM45U and AN945MPM to clarify the sludge. The efficiency of the method depends particularly on two factors: the amount of coagulant and the solid concentration of the sludge to be treated. Thus, with a mud concentration of 47.7 g/L, the average optimal amount of the two coagulants was 25 mg/L. With both coagulants, water turbidity passed from 60 x 103 NTU to approximately 3 NTU after clarification with the optimal amount of the two coagulants. RM45U reduced concentrations of Pb by 40%, Zn by 98.8%, Fe by 80.6%, and Cd by 32.8%. AN945MPM reduced Pb by 20%, Zn by 98.5%, Fe by 48%, and Cd by 32.8%.  相似文献   

18.
为了评价土壤中重金属污染程度,采用模糊数学法研究了最大隶属度、污染程度等,评价结果表明:研究区域土壤Zn、Pb、Cu、Cd、As、Hg、Ni和Cr最大值浓度超出背景值16.25、14.87、4.76、9.79、10.70、11.68、1.22和1.06倍,土壤受到Zn、Pb、Cu、Cd、As和Hg六种重金属元素的污染;模糊数学法综合评价重金属元素的最大隶属度为0.472,污染程度为三级污染。  相似文献   

19.
储溱 《资源环境与工程》2006,20(3):327-328,331
将电感耦合等离子体光谱(ICP-AES)和质谱(ICP-MS)相结合,直接测定生态地球化学评价水质样品中的20多种元素(Ca、Mg、P、Fe、Mn、A l、Ba、Sr、S i、L i、Be、V、Cr、Ti、Co、N i、Cu、Zn、Mo、Cd、Sn、Pb),方法灵敏、快速、简便。  相似文献   

20.
地下煤火土壤典型重金属分布特征   总被引:1,自引:0,他引:1       下载免费PDF全文
曾强  聂静  蒲燕 《煤炭学报》2016,41(8):1989-1996
通过采集乌鲁木齐大泉湖火区土壤样及实验室测定,研究了火区土壤理化性质与重金属Hg,As,Cu,Pb,Cr,Zn,Ni空间分布特征。结果表明:温度正常区土壤温度随采样深度增加的幅度较温度异常区小;温度正常、温度异常区土壤有机质含量随深度的增加均减少,温度正常区I,II,III,IV层土壤有机质含量大于温度异常区相应土层有机质含量;温度异常区土壤层I重金属Cu,Pb,Cr,Zn,Ni含量均小于温度正常区土壤层I相应重金属含量,II层则有增加的趋势并大于温度正常区相应土层重金属含量;温度正常区、温度异常区土壤Hg,As,Cu,Ni重金属含量随深度变化幅度及波动幅度较小,而温度异常区土壤Pb,Cr,Zn重金属含量随深度变化波动幅度较温度正常区大;火区热效应、地形、土壤及气象因子是影响土壤重金属分布的主要原因。土壤典型重金属砷形态分析表明:残留态砷含量最高,水溶态砷含量最低;水溶态砷在火区取样区域内I,II,III,IV土壤层区域富集特征与各层土壤碳酸钙富集特征趋于一致;温度正常区土壤残留态砷、铁形砷含量随深度变化的趋势与土壤碳酸钙含量随深度变化趋势一致;温度异常区残留态砷含量随深度增加波动趋势与土壤有机质含量波动趋势有较强关联性;温度正常区、温度异常区均值水溶态砷含量基本稳定,表明其与温度、土壤特性等无明显相关性。  相似文献   

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