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1.
对陕西略阳某铁矿尾矿剖面0-200cm,以10cm间隔进行分层取样,并采用pH计法测定剖面各层样品的pH,采用BCR提取方法,等离子发射光谱仪(ICP-AES)测定重金属Fe、Mn、V、Cu、Ni全量及各种赋存形态的含量。结果表明:各层尾矿的pH为7.89~8.55,并随剖面深度的增加而升高,但是整个剖面pH变化不大,且处于弱碱性。重金属Fe、Mn、V、Cu、Ni的全量差别较大,但随剖面深度增加其全量变化趋势相似,其中5种金属含量最低峰值都出现在180cm剖面点处,Fe、Mn含量最大值在150cm剖面点处,V、Cu、Ni在整个剖面的最高峰值出现在10cm处,这3种金属全量随剖面深度增加而下降。5种金属在整个剖面的平均含量均超出当地土壤该种元素在土壤A层的背景值,为尾矿污染元素。形态分析中,Fe、V元素在整个剖面中以残渣态为主,Mn以可交换态及碳酸盐结合态为主,Cu和Ni以有机质及硫化物结合态和残渣态为主。5种金属潜在迁移能力顺序为MnCuNiVFe,其中Mn和Cu对环境当地环境影响最大。  相似文献   

2.
以淮南新庄孜矿煤矸石充填复垦区为研究对象,通过现场调查取样、室内测试分析等手段,对煤矸石充填复垦区不同土地利用类型、不同充填深度土壤中Cd、Cr、Cu、Zn、Pb、Mn和Hg 7种重金属的分布特征进行研究,同时采用生态风险指数法,对研究区土壤重金属潜在生态风险危害进行评价。结果表明:表层土壤中Cu、Zn、Cd、Mn和Hg 5种重金属平均值均超过当地的土壤背景值,存在不同程度的污染,且Cd污染最严重。从垂直方向来看,除Hg外土壤重金属无明显分布规律,Hg的含量随土壤深度的增加而升高。复垦区土壤重金属潜在生态风险危害严重,不同重金属潜在生态风险危害程度不同,Cd和Hg的潜在生态风险危害最大。  相似文献   

3.
贵州省煤矸石堆场径流污染特征及其对溪流水质的影响   总被引:3,自引:2,他引:1  
通过对贵州省中部关闭煤矿区煤矸石堆场地表径流及其沉积物进行样品收集与分析,探讨了降雨-径流下煤矸石中污染物的迁移规律及其对周边地表水体质量的影响.结果表明,煤矸石堆场地表径流水的pH值变化达2.64~6.38,污染物以SO2-4,Fe和Mn为主,其浓度变化受煤矸石类型及降雨强度的影响.径流沉积物在静置或扰动下浸水3~28 d后,上覆水的pH达2.78~3.71;SO2-4,Fe,Mn的浓度变化分别为27~160 mg/L,0.3~3.9 mg/L,0.6~2.8 mg/L.降雨-径流下关闭煤矿区煤矸石堆场的地表径流对周边水体质量的影响主要表现在水体酸化及Fe,Mn污染严重.  相似文献   

4.
通过HCl、柠檬酸、EDTA这3种提取剂对Pb、Cd、Cu、Zn污染土壤的漫提试验,研究了土壤清洗洗脱重金属的效果,并探讨了土壤清洗导致K、Ca、Mg、Fe、Mn这几种营养元素的流失和有效性的改变。试验结果表明,土壤清洗能有效地洗脱土壤中的Ph、Cd、Cu、Zn,伺时也造成了土壤中K、Ca、Mg、Fe、Mn的流失,降低了其中部分营养元素的有效性。EDTA对重金属的洗脱能力大于HCl和柠檬酸。HCl漫提造成的K、Ca、Mg的流失量大于柠檬酸和EDTA,柠檬酸浸提造成的Fe流失量大于HCl和EDTA,EDTA漫提造成的Mn流失量大于HCl和柠檬酸。HCl和柠檬酸浸提降低了土壤K、Ca、Mg的有效性EDTA浸提提高了土壤K的有效性。降低了土壤Ca的有效性。在高浓度时(50mmol/L),EDTA显著地降低了土壤Mg的有效性。HCl漫提导致土壤K的有效性下降比柠檬酸严重,高浓度的EDTA浸提导致土壤Ca的有效性下降比HCl和柠檬酸严重。HCl、柠檬酸、EDTA浸提都能提高土壤中Fe的有效性.且EDTA的效应大于其它2种萃取剂;在低浓度时,3种提取剂都能提高土壤中Mn的有效性,且以柠檬酸的作用最为明显,当提取剂浓度增加时,Mn的有效性有所回落。  相似文献   

5.
[目的] 探讨植被自然恢复下植被类型对煤矸石堆场Fe,Mn淋溶迁移的影响及其作用效果,为煤矿区煤矸石堆场的生态环境治理及生态修复提供科学依据。[方法] 通过对贵州省中部废弃煤矿区不同植被条件下煤矸石堆场地表径流进行采样分析,同时通过移植煤矸石堆场上生长的马尾松、光皮桦和类芦进行盆栽试验以及采集基质渗透水样品。[结果] 马尾松、光皮桦及类芦生长的煤矸石基质渗透水和煤矸石堆场地表径流水中Fe,Mn含量均显著地低于无植物生长的煤矸石,煤矸石堆场植被自然恢复后地表径流水中Fe,Mn含量下降率分别达45.27%~85.60%,60.17%~90.13%,植被作用效果的大小顺序为:马尾松幼林 > 阔叶树幼林 > 类芦草丛。同时,马尾松幼林、阔叶树幼林、类芦草丛煤矸石堆场地表径流水中泥沙含量分别比无植被裸露的煤矸石堆场平均减少了40.18%,30.67%,27.91%。煤矸石中矿物颗粒态Fe,Mn的迁移量也出现明显的降低。[结论] 植被自然恢复能显著地减少煤矸石堆场Fe,Mn向水体的迁移及改善废弃煤矿区地表水环境质量。植物生长,特别是马尾松生长对减少煤矸石中Fe向水体迁移产生的环境效应大于Mn。  相似文献   

6.
为了解鱼洞河流域废弃煤矿矿井水外排对水环境的影响,测定了河流水体及矿井水的pH值,SO_4~(2-)及重金属(Fe,Mn,Cu,Cd,Pb,Zn)浓度和底泥中重金属(Fe,Mn,Cu,Cd,Pb,Zn)含量。结果表明:矿井水呈酸性,Fe,Mn,Zn超出当地矿井水排放标准。鱼洞河流域中河流水体pH值,SO_4~(2-),Fe,Mn和Cd浓度超出地表水水源地相关标准限值,各河段上游水体及重安江水质较好,综合污染指数法评价结果为无污染,受矿井水排入的影响,各河段下游水体pH值,SO_4~(2-),Fe,Mn明显超标,评价结果为重度污染。相关性分析及主成分分析结果表明:河流水体主要受矿井水及自然成因两方面影响。鱼洞河流域底泥中Cu,Mn未超出贵州省土壤背景值,而Fe,Cd,Pb,Zn均存在一定程度的超标,地累积指数法评价结果表明:鱼洞河流域河流底泥受Cd,Pb,Fe的轻微污染,矿井排水口底泥受Fe中度至强污染。  相似文献   

7.
酸性森林土壤中Ca-H-Al交换过程与铝的溶解机制研究   总被引:2,自引:0,他引:2       下载免费PDF全文
华南酸性森林土壤分别在pH值为3.46、4.24和4.84条件下用含不同浓度盐基离子(Ca^2+)的酸性浸提液浸提,以查明降水中盐基离子对土壤水中Al和H^+的影响。实验结果表明:随着Ca^2+浓度的增加,土壤浸出液中H^+和Al都有增加的趋势。随着Ca^2+浓度的变化,H^+和Al有不同的来源:当Ca^2+〈0.5mmol L^-1,土壤主要通过Ca—H交换机制释放H^+,浸出液中Al主要来源于土壤活性铝的溶解;当Ca^2+〉0.5mmolL^-1时,由于Ca—Al交换反应,浸出液中Al随Ca^2+浓度增加而显著增加,此时H^+主要来源于Al的水解反应。浸出液中pH—pAl关系也随pH值(或Ca^2+浓度)的变化有显著不同:当浸出液pH〉3.7(Ca^2+〈0.5mmolL^-1)时,浸出液中Al^3+活度随pH的变化幅度较小,这可能是酸性土壤中活性铝已显著流失的缘故;当pH〈3.7(Ca^2+〉0.5mmol L^-1)时H^+对于Al浓度具有较强的依赖性,故pH随Al^3+活度增加而显著降低。因此,降水中盐基离子的增加能够引起土壤水乃至地表水中酸性阳离子(特别是Al)的迅速增加,可能造成对水生生物的突发性影响。  相似文献   

8.
在模拟酸雨作用下 ,研究了重金属污染和未污染的酸性红壤和黄红壤中铝和水溶性有机质的溶出以及对重金属活动性的影响。结果表明 ,随模拟酸雨pH值下降 ,土壤pH值和盐基饱和度明显降低 ,而交换性酸度明显增加 ,污染土壤中交换性氢含量比未污染土壤高 ,而交换性铝含量比未污染土壤低。铝溶出量与模拟酸雨pH值密切相关 ,当模拟酸雨pH值在 5 .60~ 3.5 0时 ,供试红壤浸出液中铝浓度几乎在同一水平 ;当pH≥ 4 .5 0时 ,供试黄红壤中溶出铝亦未明显变化 ;当模拟酸雨pH =3.5 0时 ,未污染黄红壤中铝溶出明显增多 ;当pH =3.0 0时 ,供试土壤中铝溶出量急剧增加。随模拟酸雨pH值下降 ,污染土壤中铝溶出比未污染土壤低 ,而有效态重金属活动性明显增加 ;污染土壤中水溶性有机质比未污染土壤溶出明显增加 ,水溶性有机质 -重金属络合体促进了重金属的溶解迁移行为。  相似文献   

9.
通过分析基于风干土样和新鲜土样、ASI(Agro Services International Inc., ASI)浸提剂和改进ASI浸提剂进行测量的土壤有效养分含量的相关性,探索一种基于新鲜土样和联合浸提剂进行土壤有效养分测试的方法。结果表明,利用ASI浸提剂测量的北京潮土新鲜土样的NO3--N和NH4+-N、有效P、K、Ca、Mg、Cu、Fe、Mn、Zn、有机质含量、及pH值,与风干土样的测量值均呈显著的线性相关关系,经该线性方程回归检验的测量相对误差小于5%~9%;利用改进ASI浸提剂测量的新鲜土样和风干土样的NH4+-N、有效P、K、Ca、Mg、Cu、Fe、Mn、Zn含量与基于ASI浸提剂测量的也呈显著的线性相关关系,经该线性方程回归检验的测量相对误差小于5%~8%。因此,基于新鲜土样和改进ASI浸提剂测量石灰性土壤有效养分含量是可行的,可为车载式土壤养分检测提供一种快捷的土样浸提前处理方法。  相似文献   

10.
为了解包头市铜厂周边地区土壤剖面中重金属污染状况,采用火焰原子吸收分光光度法和Tessier连续提取法,对土壤中6种重金属(Cu,Zn,Mn,Ni,Pb和Cd)的垂直分布特征、形态及潜在生物可利用性进行了分析。结果表明:研究区土壤剖面各层土壤中6种重金属含量均超过内蒙古土壤背景值,Cu,Pb和Cd为主要污染物。随采样深度的增加,Cu,Zn,Pb和Mn的含量呈现下降趋势,且由相关性系数可知重金属Cu,Zn和Pb可能有相同人为或自然污染源;土壤剖面中6种重金属均主要以残渣态存在,含量均在50%以上,对生物危害较小;潜在生物可利用性分析结果为:Cu(32.61%) > Mn(31.85%) > Ni(24.90%) > Zn(16.60%) > Cd(15.23%) > Pb(14.87%),Cu和Mn的潜在生物可利用性较大,其次为Ni,Zn,Cd和Pb潜在生物可利用性较小。  相似文献   

11.
Abstract

Wetland soils (hydric soils) are unique in their chemical characteristics compared to upland soils. It is known that they are capable of removing a variety of wastes from polluted water entering the wetland including metals and potentially toxic heavy metals. When these metals are determined in wetland soils, it is necessary to use the proper chemical extractant(s). Four commonly used chemical extractants (Mehlich 1, Mehlich 3, 0.1M HCl, and DTPA) for soil fertility evaluation were selected to measure metal concentrations of three different wetland soils/spoils. Soil samples were collected from the constructed wetland cells which were lined with Abernathy silt loam topsoil and two different mine spoil materials [collected from active coal strip‐mined sites in Alabama (pH 5.9) and Tennessee (pH 3.2)]. Mehlich 3 extracted the most zinc (Zn), iron (Fe), manganese (Mn), calcium (Ca), magnesium (Mg), potassium (K), sodiumm (Na), and aluminum (Al), while 0.1M HC1 extracted more cadmium (Cd), copper (Cu), and lead (Pb). Extractants followed the same trend in removing quantities of the metals from the three soil/spoil materials, with DTPA generally extracting the least amount of the metal (the trend was Mehlich 3 > 0.1N HCl > Mehlich 1 > DTPA). However, DTPA removed larger quantities of metals from Tennessee spoil compared to Alabama spoil and topsoil, suggesting the higher effectiveness of DTPA under acidic conditions. Metal concentrations in plant tissue did not show a definite trend in correlation with metals extracted by the four chemical extractants.  相似文献   

12.
The geochemical behavior of metals, including Fe, Mn, Pb and Zn, in contaminated paddy soils was investigated during the cultivation of rice crops through laboratory microcosm experiments. From the two paddy fields contaminated by mine tailings, Siheung and Deokeum in Korea, paddy soils were collected and analyzed for their geochemical characteristics. The Siheung paddy soil showed higher levels of heavy metals, whereas the higher potential for the release of metals was anticipated due to the extremely acidic conditions at Deokeum. In microcosm experiments of flooded paddy soils over 18 weeks, Fe and Mn were released in subsurface pore waters by reductive dissolution, and Pb and Zn were dissolved in high amounts at the surface by oxidation of sulfides. Although amorphous Fe oxide-rich layers were formed at the surface of both paddy soils, the release of Pb and Zn were controlled at the surface by these layers only under slightly alkaline conditions at Siheung. Lead and Zn were associated with the reducible and carbonate fractions at the surface paddy soil of Siheung from the sequential extraction on core samples collected during the flooded period. In the acidic conditions at Deokeum, Pb and Zn were continuously released until the late stage of flooding. A great increase in the exchangeable fraction of metals was observed after the soils had drained. The bioavailability of metals for rice crops would be high under acidic conditions at Deokeum, despite the lower levels of heavy metal contamination.  相似文献   

13.
研究煤矿矸石地的土壤重金属分布及污染状况可为污染治理和植被恢复提供科学依据。通过测定陕西省铜川市三里洞煤矿煤矸石风化土壤中Cu,Cr,Cd,Ni,Zn,Pb共6种重金属元素的含量,应用地质累积指数法和潜在生态危险指数法对排矸场风化土壤污染状况进行了分析与评价。结果表明:在地形较平坦,排矸年限长,植被覆盖度大的地段,重金属元素含量较高,而且分布趋于稳定。在坡地,坡下部重金属富集和积累比较明显,一般坡下部重金属含量高于坡上部和坡中部。排矸场Cd污染最为严重,为中度或偏重度污染,且潜在生态危险水平也达到了重度或极重;Cu,Ni,Zn为轻度污染,Cr和Pb污染轻微,个别地段达到轻度污染,这5种重金属元素均达到轻度潜在生态危险水平。可见,该排矸场亟需加强重金属污染的预防和治理。  相似文献   

14.
[目的] 对三峡库区坡面土壤与消落带沉积泥沙中重金属含量特征开展研究,为该区重金属污染评价提供理论与数据支持。[方法] 在三峡库区选取53个采样点,分析区域内坡面土壤与消落带沉积泥沙中Cr,Cu,Pb,Zn,Mn 5种重金属元素的含量,利用单因子污染指数法、内梅罗综合指数法、地累积指数法和潜在生态风险指数法开展污染状况评价。[结果] 研究区域内重金属含量平均值大小依次为:Mn>Zn>Cr>Cu>Pb,仅Cu,Zn和Mn存在污染。Zn和Mn在消落带沉积泥沙与坡面土壤中皆富集,而Cu仅在坡面土壤中富集。研究区域内重金属在空间分布上呈上、下游高,中游低分布。单因子污染指数法表明,研究区内仅存在Zn (Pia=1.07)的轻度污染与Mn (Pia=2.65)的中度污染。研究区域内梅罗综合指数为2.93,为中度污染。根据地累积指数法,研究区域内仅存在Mn轻度污染,其余重金属皆为无污染。Cr,Cu,Pb,Zn,Mn的潜在生态危害皆为轻微生态危害;研究区域的综合生态危害指数为14.09,为轻微生态危害。[结论] 研究区域内Cr含量主要受到研究区地质背景影响,而Cu,Pb,Zn和Mn含量同时受到地质背景与人类活动的影响。研究区内存在Mn和Zn污染,且有轻微生态危害。  相似文献   

15.
水体沉积物是重金属元素的重要载体,其含量高低能反映水环境质量现状。采集滇池内湖滨带沉积物样品,分析了滇池内湖滨带表层沉积物中Pb、Cd、Cu、Zn、Cr、Ni、Fe、Mn 8种重金属元素含量特征,并用Hakanson潜在生态危害指数法评价其生态危害,旨在为合理预防和治理滇池内湖滨带的重金属污染以及内湖滨带生态系统的修复提供基础资料。结果表明,与“全国土壤环境质量标准”对比,表层沉积物中主要是Cd、Cu、Zn超标,重金属污染强度总体上是草海>外海。不同重金属间的相关性分析结果表明,Cu-Cd之间呈极显著相关,说明这两种元素污染源可能相同,几种污染重金属与胶体矿物元素Fe、Mn间的相关性不大,说明在所调查沉积物中,Fe/Mn氧化物或氢氧化物共沉淀或吸附Pb、Cd、Cu、Zn、Cr、Ni元素量较少。由潜在生态风险评价结果可知,滇池内湖滨带表层沉积物已具极强生态危害,各重金属对滇池内湖滨带生态风险影响程度由高到低依次为:Cd〉Cu〉Pb〉Ni〉Zn≈Cr。  相似文献   

16.
To assess the mobilities of Pb, Cd, and Zn from a contaminated soil, the effects of redox potential and pH value on metal solubilities were investigated. Both redox potential and pH were found to greatly affect heavy metal solubility in the soil. Results showed that the soil suspension under continuous oxygen aeration for 21 days resulted in increases of redox potential from 290 to 440 mV and pH value from 6.9 to 7.0, respectively. Soluble concentrations of Pb, Cd, and Zn varied with time, and were all lower than 1 mg kg?1. When the soil suspension was aerated with nitrogen, final redox potential was ?140 mV and pH value of 7.1. The soluble metal concentrations were slightly higher than those aerated with oxygen. The equilibrium solubility experiments were conducted under three different pH values (3.3, 5.0, 8.0) and three redox potential (325, 0, ?100 mV). Results showed that metals were sparingly soluble under alkaline conditions (pH = 8.0). Metal solubilities were higher when under slightly acidic conditions (pH = 5.0), and increased drastically when pH was kept at 3.3. When solubilities were compared under same pH values, it was observed that metal solubilities increased as redox potential decreased. Generally speaking, acidic and reducing conditions were most favorable for metal solubilization, and the effect of pH was more significant than that of redox potential. It was proposed that heavy metals were mostly adsorbed onto Fe-Mn oxyhydroxides. The pH-dependent metal adsorption reaction and the dissolution of Fe-Mn oxyhydroxides under reducing conditions was the mechanism controlling the release of heavy metals from soils.  相似文献   

17.
Environmental Impact of Coal Mining on Water Regime and Its Management   总被引:1,自引:0,他引:1  
Coal mining is one of the core industries that contribute to the economic development of a country but deteriorate theenvironment. Being the primary source of energy coal has becomeessential to meet the energy demand of a country. It isexcavated by both opencast and underground mining methods andaffects the environment, especially water resources, by discharginghuge amounts of mine water. The mine water may be acidic orneutral depending upon the pyrite content in the coal asinorganic impurities. Acid mine drainage occurs in those mines in which sulphur content is found in the range of 1–5% in the form of Pyrite (FeS2). It degrades the water qualityof the region in terms of lowering the pH of the surrounding water resources and increasing the level of total suspended solids, total dissolved solids and some heavy metals. In non acidic mines, water quality shows high hardness, TSS and bacterial contaminants. The leachate water from overburden dump are found enriched in metal concentration especially Fe, Cu, Mn and Ni except in one of the clayey dumps. High values ofhardness of mine water reduces it's utility in domestic purposes.The article illustrates the quality of acidic and non acidic minewater and leachate characteristics of opencast coal mining OBdumps. Pollutants such as TSS, TDS, oil and grease and heavy metalare found in the coal mining waste effluents. Management ofthese liquid waste at the primary level and secondary level havealso been suggested to control the pollution level at the source.  相似文献   

18.
内蒙古草原白乃庙铜矿区土壤重金属污染特征研究   总被引:4,自引:0,他引:4  
对位于内蒙古荒漠草原上的白乃庙铜矿采选矿区土壤和尾矿区周围土壤重金属污染状况进行了调查研究。结果表明,矿区土壤中Cu、Cr、Ni、Fe和Mn浓度均高于内蒙古土壤平均值。单因子指数法评价结果表明,五个调查区域土壤都受到了重金属Cu、Cr、Ni、Mn、Fe的污染,其中Cu为重污染,Cr、Ni、Mn、Fe为轻污染,Pb为安全级别,Zn和As只对某些区域有轻污染。综合污染指数法评价结果表明,五个调查区域的土壤重金属污染等级均属重污染,主要贡献元素是Cu,其次是Cr、Ni、Mn、Fe,这与尾矿砂中这些重金属的浓度是相对应的。由于周边地形复杂,多为低山丘陵,所以该地区主导风向对于尾矿库区不同方向土壤重金属污染水平的影响差异并不显著。  相似文献   

19.
为研究复垦年限对煤矸山土壤重金属的影响,以山西省霍州市曹村煤矿煤矸山复垦3 a,5 a,7 a和9 a农田为研究对象,对复垦地土壤重金属Hg,Cd,Pb,As和Ni的质量分数及其污染状况进行了分析。结果表明:(1)煤矸山复垦农田0—20 cm和20—40 cm土层土壤重金属质量分数有随复垦年限增加而增加的趋势,其中Pb,Cd表现最明显,而Hg的增加趋势主要出现在20—40 cm土层;同时,煤矸山复垦农田土壤重金属质量分数均不同程度地高于当地普通农田,尤其在20—40 cm土层表现更明显;(2)单因子污染指数表明,Hg和As在0—20 cm和20—40 cm土层污染程度随年限没有变化,分别为重度污染和轻微污染,Pb和Cd在0—20 cm也没有变化,分别为轻微污染和轻度污染,但在20—40 cm土层随年限增长达到轻度污染和中度污染;综合污染指数表明,复垦农田在0—20 cm和20—40 cm土层污染指数均表现为随复垦年限增加而增加的趋势,4种复垦年限农田均达到重度污染。研究结果有助于指导煤矸山植被恢复和复垦地的合理利用。  相似文献   

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