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山西山阴、应县一带砷中毒区砷的环境地球化学研究 总被引：27，自引：0，他引：27
通过对山西省大同盆地砷中毒区的环境地球化学调查,对病区环境中砷的来源、价态及砷的迁移、富集、转化规律进行了研究。结果表明,盆地周边岩石、煤系地层为富砷岩系,构成砷的原生物源。自然和人为作用将环境中的砷释放出来,在第四系含水层湖冲积物中富集成次生富砷储集层,为水砷的直接来源。由于含砷水在黄水河构造凹地的深层滞留,加之干旱蒸发使水中砷进一步浓集成高砷水,富炭质含水层的还原环境促使Ａｓ５＋向Ａｓ３＋转化,提高了水的毒性,加剧了砷中毒的发生。 相似文献
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土壤环境中砷元素的生态效应 总被引：1，自引：0，他引：1
论述了各环境介质中砷元素的分布特点,指出土壤第Ⅱ环境中的砷主要来源于人为活动。砷主要富集于土壤表层,且主要以稳定矿物形式存在;但当土壤砷总量高时其可溶性砷量亦相应高,砷在土壤中易形成Fe、Al、Ca型砷化物而被固定;当土壤pH值增高至中性或碱性时,砷易转化为迁移能力更强、毒性更大的三价砷。砷对作物、人体生态系统危害作用明显,砷通过蔬菜对人体的危害甚于谷物,应采取有效措施防治土壤中砷污染。 相似文献
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土壤中砷的形态分析和生物有效性研究进展 总被引：19，自引：0，他引：19
土壤砷污染是当今全球十分严重的环境与健康问题之一。土壤砷形态及生物有效性研究是开展污染诊断、评估环境健康风险及开展砷污染土壤修复的重要依据。目前土壤砷形态的研究方法包括化学选择性提取操作定义法、溶剂提取仪器测定或吸附材料选择性分离法和同步辐射X射线近边能谱（XANES）直接测定法,这些方法相互结合在土壤砷的形态转化研究中发挥着重要作用。目前关于生物有效性研究存在多种方法并存的局面,化学提取法相对经济、方便,但存在很大的局限性,往往不能真实反映土壤砷的有效态含量,只能作为环境危害程度识别的参考;植物指示法需选择敏感性植物方能有效地指示土壤砷对环境与健康的潜在危害;土壤动物与微生物指示法代表了未来开展砷污染早期预警的发展方向,具有广阔的应用前景。模拟肠胃液提取法(In Vitro Gastrointestinal Method)比较接近动物或人体对土壤砷污染的真实吸收状态,在环境健康风险评价中发挥着重要作用。目前国外已发展出采用兔、仔猪和猴的动物模型以研究经口摄入的生物有效性砷,但尚不清楚哪种动物模型更能准确反映砷对人体的生物有效性。 相似文献
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环境中不同的污染物可经过各种迁移转化途径,通过食物链进入人体,对人体的健康带来威胁.土壤污染物中以重金属比较突出,其中Hg、Cd、Pb、Cr以及类金属As等对生物毒性显著,Zn、Cu、Ni、Co、Sn等对生物的毒性一般.利用1：5万敖汉旗幅水系及土壤地球化学勘查所取得的数据,采用单因子污染指数法评价单元素污染程度,并采用重金属元素毒性响应系数评价区域有毒元素潜在风险,得到研究区主要潜在生态危害元素为Cd、Pb、As,其中Cd元素危害最大,主要潜在污染因素为采石场、采矿场、垃圾场等人为地质作用因素以及原生地质环境因素. 相似文献
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地下水中铵根、砷、溶解铁的共存是一个普遍现象。它们之间发生强烈的相互作用,并影响地下水系统的氮循环和砷迁移转化。文章在系统总结地下水氮循环过程及影响因素、地下水氮循环功能微生物及特征、地下水砷富集的水文地球化学过程等国内外研究现状的基础上,深入分析了地下水系统中的氮循环过程（硝化、反硝化、铁铵氧化、厌氧铵氧化、硝酸根异化还原产铵等）对地下水砷迁移转化的影响,总结出含水层中铁氧化物和溶解态Fe(II)的动态转化是氮循环影响地下水中砷迁移转化的重要桥梁。据此提出不同氧化还原环境的含水层中氮循环过程、地下水氮循环与砷迁移转化耦合机理、Fe(III)-Fe(II)的循环-地下水氮循环-砷迁移转化之间的相互作用过程、地表水-地下水相互作用带氮-铁-砷的循环过程及其对人类活动的响应等是今后该领域需要关注的重要科学问题和主要发展趋势。这些科学问题的解决不仅有利于识别地下水中氮的来源和迁移转化,而且有利于提高对高砷地下水富集机理的整体认识。 相似文献
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烟台市是山东半岛蓝色经济区核心城市之一,通过对山东省烟台市生态地球化学资料的系统整理,研究土壤重金属污染现状与分布迁移规律,发现土壤主要污染因子是As、Cd、Hg、Cu、Pb、Zn等重金属元素污染,工矿三废排放是土壤重金属污染的主要原因;主要致污因子砷是环境中毒性最大的有害元素之一。土壤-苹果树体系中As迁移及形态转化规律为:植物根系吸收土壤中的砷,并在根部发生了AsⅤ→AsⅢ的还原作用,由植物的根部向上迁移过程中,AsⅢ的比例逐渐降低。砷在根系土-植物体系中的分布为:根系土>根>叶子>茎>苹果。 相似文献
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《地学前缘(英文版)》2021,12(3)
More than 2.5 billion people on the globe rely on groundwater for drinking and providing high-quality drinking water has become one of the major challenges of human society.Although groundwater is considered as safe,high concentrations of heavy metals like arsenic(As) can pose potential human health concerns and hazards.In this paper, we present an overview of the current scenario of arsenic contamination of groundwater in various countries across the globe with an emphasis on the Indian Peninsula.With several newly affected regions reported during the last decade, a significant increase has been observed in the global scenario of arsenic contamination.It is estimated that nearly 108 countries are affected by arsenic contamination in groundwater(with concentration beyond maximum permissible limit of 10 ppb recommended by the World Health Organization.The highest among these are from Asia(32) and Europe(31), followed by regions like Africa(20), North America(11), South America(9) and Australia(4).More than 230 million people worldwide, which include 180 million from Asia, are at risk of arsenic poisoning.Southeast Asian countries, Bangladesh, India, Pakistan,China, Nepal, Vietnam, Burma, Thailand and Cambodia, are the most affected.In India, 20 states and 4 Union Territories have so far been affected by arsenic contamination in groundwater.An attempt to evaluate the correlation between arsenic poisoning and aquifer type shows that the groundwater extracted from unconsolidated sedimentary aquifers, particularly those which are located within the younger orogenic belts of the world, are the worst affected.More than 90% of arsenic pollution is inferred to be geogenic.We infer that alluvial sediments are the major source for arsenic contamination in groundwater and we postulate a strong relation with plate tectonic processes, mountain building, erosion and sedimentation.Prolonged consumption of arsenic-contaminated groundwater results in severe health issues like skin, lung, kidney and bladder cancer; coronary heart disease;bronchiectasis; hyperkeratosis and arsenicosis.Since the major source of arsenic in groundwater is of geogenic origin, the extend of pollution is complexly linked with aquifer geometry and aquifer properties of a region.Therefore, remedial measures are to be designed based on the source mineral, climatological and hydrogeological scenario of the affected region.The corrective measures available include removing arsenic from groundwater using filters, exploring deeper or alternative aquifers, treatment of the aquifer itself, dilution method by artificial recharge to groundwater, conjunctive use, and installation of nano-filter, among other procedures.The vast majority of people affected by arsenic contamination in the Asian countries are the poor who live in rural areas and are not aware of the arsenic poisoning and treatment protocols.Therefore, creating awareness and providing proper medical care to these people remain as a great challenge.Very few policy actions have been taken at international level over the past decade to reduce arsenic contamination in drinking water, with the goal of preventing toxic impacts on human health.We recommend that that United Nations Environment Programme(UNEP) and WHO should take stock of the global arsenic poisoning situation and launch a global drive to create awareness among people/medical professionals/health workers/administrators on this global concern. 相似文献
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砷的水地球化学及其环境效应 总被引：15，自引：1，他引：15
砷在水环境中的迁移和富集可以产生严重的砷污染，砷在自然水系中主要以无机砷酸盐（AsO4^3-）和亚砷酸盐（AsO3^3-）两种形式存在，而砷的有机化合物的含量一般都很低，砷酸盐在富氧化性的水体中占优势，而亚砷酸盐则富集于还原性水体中，水体中As3 和As5 的相对含量主要受氧化还原条件和一些吸附一解吸平衡过程控制，As3 类比As5 类的毒性强得多，而无机砷化合物比有机砷化合物的毒性大，在pH值为5－6时，As^5 不易被还原成气态AsH3，而s^3 却能定量地被还原出来，根据这一性质，可完成水体中As3 和As5 的测定，砷在饮用水中的安全阀值仅为10ug/L，水体中高砷的危害可以通过水质净化予在消除或降低，铁的化学沉淀和吸附法，石灰软化法，活性氧化铝净化法和逆流渗透法等都可以有效地去除或降低饮用水中砷的含量。 相似文献
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Arsenic toxicity in groundwater in the Ganges delta and some low-lying areas in the Bengal basin is confined to middle Holocene
sediments. Dissected terraces and highlands of Pleistocene and early Holocene deposits are free of such problems. Arsenic-rich
pyrite or other arsenic minerals are rare or absent in the affected sediments. Arsenic appears to occur adsorbed on iron hydroxide-coated
sand grains and clay minerals and is transported in soluble form and co-precipitated with, or is scavenged by, Fe(III) and
Mn(IV) in the sediments. It became preferentially entrapped in fine-grained and organic-rich sediments during mid-Holocene
sea-level rises in deltaic and some low-lying areas of the Bengal basin. It was liberated subsequently under reducing conditions
and mediated further by microbial action. Intensive extraction of groundwater for irrigation and application of phosphate
fertilizer possibly triggered the recent release of arsenic to groundwater. This practice has induced groundwater flow, mobilizing
phosphate derived from fertilizer, as well as from decayed organic matter, which has promoted the growth of sediment biota
and aided the further release of arsenic. However, the environment is not sufficiently reducing to mobilize iron and arsenic
in groundwater in the Ganges floodplains upstream of Rajmahal. Thus, arsenic toxicity in the groundwater of the Bengal basin
is caused by its natural setting, but also appears to be triggered by recent anthropogenic activities.
Received: 23 August 1999 · Accepted: 16 November 1999 相似文献
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S. L. Wang C. Y. Lin X. Z. Cao X. Zhong 《International Journal of Environmental Science and Technology》2012,9(1):31-40
The Nansi Lake has been seriously affected by long-term intensive industrial and urban activities. The objectives of this study were to determine the content, distribution, and ecological risk of arsenic and investigate the geochemical relationships between arsenic forms and sediment mineral phases of the Nansi Lake. Twenty samples of surface sediments were collected and analyzed for arsenic contents and chemical forms. Results indicated that total content of arsenic in the sediment samples averaged 13.45?mg/kg and ranged from 8.27 to 21.75?mg/kg. The arsenic was mostly associated with iron oxides (67.3%), followed by the association with the residual fraction (19.2%). In addition, total content of arsenic was positively correlated with the organic matter and iron contents in the sediment. The molar ratios of iron oxide bound arsenic content to iron content are lower than the maximal molar ratios of arsenic to iron for natural hematite, magnetite, and goethite. The total content of arsenic in the sediment samples was usually higher than threshold effect concentration of 9.79?mg/kg, but lower than probable effect concentration of 33.0?mg/kg for arsenic in freshwater sediments. Adverse effects or toxicity to the aquatic organisms, caused by arsenic in the sediments of the Nansi Lake, will likely occur at these levels of arsenic contamination. 相似文献
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Groundwater chemistry and mass transfers in the Independence aquifer,central Mexico,by using multivariate statistics and mass-balance models 总被引：2，自引：0，他引：2
In the light of progressive depletion of groundwater reservoir and water quality deterioration of the Independence aquifer, an investigation on chemical data of dissolved major and minor constituents in 246 recent groundwater samples was performed. The main objective was the detection of processes responsible for the geochemical evolution and mineralization throughout the area. Multivariate techniques revealed different sources of solutes (a) dissolution of calcium and magnesium carbonate minerals, (b) weathering of acid volcanic minerals, (c) alteration of manganese containing alkaline silicates, (d) leaching of halite deposits of meteoric origin, (e) contamination from agricultural and urban wastewaters, and (f) evaporative effects due to intensive irrigation. Although nitrate contamination is associated with pollution from intensive cultivated areas, natural contamination plays an important role in the study area. The investigation reveals that weathering of acid volcanic rocks (rhyolite) and oxidation of arsenic bearing sulfide minerals are the responsible processes for high fluorine (up to 16 mg/l) and arsenic (up to 0.12 mg/l) contents, respectively, exceeding the Mexican maximum admissible concentration for drinking water. Except for kaolinite, all recharge processes are dissolution oriented (CO2, calcite, dolomite, K-feldspar, plagioclase). Silicate precipitation (amorphous silica and chalcedony) is of growing importance in discharge zones. Cation exchange is not an important issue in the whole study area. 相似文献
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Chaoyang WEI 《中国地球化学学报》2006,25(B08):83-83
Municipal solid waste incinerator （MSWI） fly ash is world-widely defined as hazardous waste because of its high concentration of heavy metals and high toxic equivalents of dioxin-like compounds. Therefore, if not properly disposed, it would pose a risk of being released into the environment including soil and groundwater. Heavy metals in the MSWI fly ash are considered as the most dangerous component owing to their leaching characteristics and migration capability. To get a better knowledge of their releasing behavior, it is important to assess the potential environmental mobility of heavy metals in MSWI fly ash and to investigate the factors affecting their leaching characteristics. Fly ashes from four MSW incinerators were characterized and leaching of heavy metals according to both Chinese HVEP and USA TCLP were performed. A geochemical modeling computer program, PHREEQC （version 2） was used to calculate the equilibrium concentration, the speciation and possible precipitation of heavy metals in the leaching systems. In the modeling, the heavy metals, Cd, Cr, Cu, Ni, Pb, Zn, were input as master aqueous species in solutions, while the major and accessory components, Ca, Na, K, Cl, S, etc., were defined as finite solids. The agreement between the experimental results and the modeling ones varies for different metals as well as for different fly ashes. In general, the fitness of the modeling for different heavy metals is： Pb〉Zn〉Cd〉Cu. The modeling is excellent for fly ashes with low calcium but high chloride content, or with high concentration of heavy metals, which favor the implicit postulation of component input in the modeling, i.e., high availability of heavy metals. 相似文献
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A. B. Vicente M. M. Jordán T. Sanfeliu A. Sánchez Ma D. Esteban 《Environmental Earth Sciences》2012,66(3):879-888
The objective of this study was to elaborate a series of mathematical models with the aim of short-term prediction of TSP, PM10, As, Cd, Ni and Pb in ambient air. These pollutants depend on some known variables (meteorological variables). The reason for choosing this pollutant type is that particulate matter may present a much higher potential risk despite its low representativeness as compared with the gas pollutant group. A positive correlation between high particle concentrations and deterioration in public health has been shown in recent studies. The elements As, Cd, Ni and Pb in PM10 were also analyzed to determine the toxicity of these particles. The goal is to provide a useful instrument to alert the population facing possible episodes of high concentrations of atmospheric pollutants. The study was carried out in a highly industrialized area in the ceramic cluster of Castellón for 5 years (2001–2005). The origin of the contamination in this area is both natural and anthropogenic. The natural origin is due to the resuspension of mineral materials from the surrounding mountains and from the long-range transport of materials from North Africa. The anthropogenic contamination sources that stand out include the non-metallic mineral material industries (ceramic production), chemical industries (color, frit and enamel manufacturing), as well as vehicular traffic. Once the particle samples were collected in quartz fiber filters, the concentration levels of TSP and PM10 were determined gravimetrically. The chemical analysis of the filters was carried out by ICP-MS. Predictive models have been constructed by using multiple regression analysis together with time series models (ARIMA). The SPSS 14.0 statistical software has been employed to analyze the obtained experimental data. 相似文献
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High arsenic water has been a global focus of both scientists and water supply managers because of its serious adverse impact on human health and wide distribution in the world. Processes of redox, sorption, precipitation, and dissolution release arsenic in both natural systems and in environments intensely modified by human activities. In natural systems, groundwater arsenic is controlled by lithologic geochemistry, sedimentation conditions, hydrogeologic setting and groundwater chemistry. However, in the intensely human-affected systems (such as mining and tilling areas), arsenic mobilization is dependent on the composition of the primary materials, treatment methods, storage design, and local climate. Well-designed experimental systems aid in characterizing sorption, precipitation, and redox processes associated with arsenic dynamics during water-rock interaction. Continued investigations of field sites will further refine understanding of the processes favoring arsenic mobility in the range of natural and man-made systems. The combination of field and experimental studies will lead to better understanding of arsenic cycling in all systems and sustainable management of water resources in arsenic-affected areas. 相似文献