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11.
Groundwater is a resource under stress. In both developed and developing countries, it has been found that increasing human influence has led to the contamination of the groundwater resource. To understand the magnitude of this problem, a study was conducted in 58 wards within Northern part of Kolkata, India, where water samples from tube wells were collected and analysed on essential drinking water quality parameters, prescribed by WHO. Using Principal component analysis, and Water quality index mapping, the aforementioned results have been interpreted. This has helped to depict that not only is the groundwater unsuitable for drinking, but that the parametric values have a tendency to increase abruptly within the shortest of ranges, indicating urban pollution as the root cause of contamination. This paper shall thus discuss the spatial change in groundwater quality in northern Kolkata and suggest measures which might be implemented to secure a sustainable future for the city. 相似文献
12.
Groundwater, as a drinking water source for nearly one third of the world’s urban population, plays a strategic role in the development of urbanization. The object of this study is urban areas with the largest demand for water resources, the heaviest load of groundwater pollution and the most intense development of underground projects. This study sorted out the eco-hydrological problems such as the variation of the groundwater hydrological process, the groundwater pollution, and the urban heat island of groundwater in urban areas under the background of urbanization. Furthermore, the mechanism of changes in the quantity, quality and heat of groundwater was also systematically analyzed, and the intrinsic interaction among these three factors was revealed. The study showed that changes in land use and land cover caused by the urbanization are the main reasons for the variation of groundwater hydrological process. The pollution load of urbanization construction and domestic production waste has aggravated the deterioration of groundwater quality. The increase in vertical heat flux caused by urbanization gives rise to the warming of groundwater. By summarizing the eco-hydrological problems and causes of groundwater in urbanized areas, several suggestions were proposed: Establishing the evaluation method and system of urban groundwater resources; Speeding up the technological breakthroughs of groundwater pollution control; Improving the regional control strategies for groundwater pollution; Optimizing the allocation of groundwater resources. This study will provide the theoretical basis and technical support for ensuring urban water safety, building ecological civilized cities and further promoting the sustainable development of economy and society. 相似文献
13.
Effects of heavy metal pollution on farmland soils and crops: A case study of the Xiaoqinling Gold Belt,China 总被引:1,自引:0,他引:1
《China Geology》2020,3(3):402-410
This paper focuses on the heavy metal enrichment and heavy metal pollution degree associated with mining activities in some crops and the soils of different parent materials in the Xiaoqinling Gold Belt. According to the geochemical analysis results of the soils observed in the gold belt, the soils are most highly enriched in Pb, followed by Cr, Cu, and Zn. Furthermore, they are relatively poor in Hg, Cd, and As. It is also shown that the heavy metals in all kinds of soils have the same geochemical characteristics in the gold belt. As for the crops (such as corn and wheat) in the gold belt, Zn and Cu are the most abundant elements, followed by Pb and Cr. Meanwhile, Hg, Cd, and As were found to have relatively low concentrations in the crops. The heavy metals in wheat and corn have the same geochemical characteristics in the gold belt in general. Compared to the aeolian loess soils and the crops therein, heavy metals are more enriched in diluvial and alluvial soils and the crops therein. As shown by relevant studies, the Hg, Pb, Cd, Cu, and Zn pollution are mainly caused by mining activities. Corn and wheat in the gold belt have a high tendency of risk exposure to heavy metal pollution since they are mostly affected by mining activities and feature high background values of heavy metal concentrations. Furthermore, wheat is more liable to be enriched in heavy metals than corn is grown in all types of soils. The Hg pollution in soils leads to Hg accumulation, increasing the risk of Hg uptake in crops, and further affecting human health. This study will provide a scientific basis for the control and management of heavy metals in farmland soils of mining areas. 相似文献
14.
15.
Analysis of the interannual variability of annual daily extreme water levels in the St Lawrence River and Lake Ontario from 1918 to 2010 下载免费PDF全文
We compared the interannual variability of annual daily maximum and minimum extreme water levels in Lake Ontario and the St Lawrence River (Sorel station) from 1918 to 2010, using several statistical tests. The interannual variability of annual daily maximum extreme water levels in Lake Ontario is characterized by a positive long‐term trend showing two shifts in mean (1929–1930 and 1942–1943) and a single shift in variance (in 1958–1959). In contrast, for the St Lawrence River, this interannual variability is characterized by a negative long‐term trend with a single shift in mean, which occurred in 1955–1956. As for annual daily minimum extreme water levels, their interannual variability shows no significant long‐term change in trend. However, for Lake Ontario, the interannual variability of these water levels shows two shifts in mean, which are synchronous with those for maximum water levels, and a single shift in variance, which occurred in 1965–1966. These changes in trend and stationarity (mean and variance) are thought to be due to factors both climatic (the Great Drought of the 1930s) and human (digging of the Seaway and construction of several dams and locks during the 1950s). Despite this change in means and variance, the four series are clearly described by the generalized extreme value distribution. Finally, annual daily maximum and minimum extreme water levels in the St Lawrence and Lake Ontario are negatively correlated with Atlantic multidecadal oscillation over the period from 1918 to 2010. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
16.
地下水质动态变化及其趋势研判是区域水资源调配决策的重要依据.本文以全国2007~2017年国家级地下水监测网水质数据为基础,结合典型地区的代表性监测组分超标特征及动态趋势,开展了地下水质动态变化过程研究,结果表明:全国地下水监测中以Ⅳ类水质点占比最大,其次为Ⅱ类水质点;Ⅰ~Ⅲ类水质点数量较少,而且占比以降低为主,Ⅳ和Ⅴ类地下水监测点逐渐增加,其中Ⅳ类水质点的比例由40.50%增加至51.45%;全国地下水质主要的超标组分为pH、总硬度、总溶解性固体、硫酸盐、氯化物、高锰酸钾指数、铁、锰、氟化物、"三氮".以华北地区、华东地区、西南地区和西北地区为代表,分析研究典型地区地下水质的动态变化过程及其影响因素,结果显示,在地下水位变化较大的地区,地下水质状况随着地下水位变化明显,在地下水位波动较小的地区,地下水质状况也基本上变化较小.研究成果对于科学评价地下水资源、合理制定区域地下水开发利用规划、防治地下水污染等具有一定的指导作用. 相似文献
17.
《Chemie der Erde / Geochemistry》2021,81(2):125748
Although antimony (Sb) and arsenic (As) exhibit similar geochemical behavior and toxicity in the environment, growing evidence suggests that their water–rock interaction behavior in contaminated rivers is quite different. Twenty-nine river water samples were collected between September and November 2018 from contaminated rivers around an antimony mine in Hunan Province, China. The concentrations of As and Sb were inversely proportional to the water flow distance. The rates and magnitudes of Sb decrease were more prominent than those of As. Silicate mineral dissolution from rocks such as silicified limestone increased the As and Sb concentration of in-mine-district (IMD) water. Dissolution of carbonate minerals, ion exchange, and competitive adsorption were the major water–rock interactions, resulting in rapidly decreasing As and Sb concentration in IMD direct impacted water and IMD indirect impacted water. The behaviors of As and Sb during water–rock interaction were dissimilar for areas dominated by carbonate and silicate minerals. 相似文献
18.
川西九龙地区锂铍矿区土壤重金属分布特征及生态风险评价 总被引:1,自引:0,他引:1
川西九龙地区是近年来中国关键矿产资源勘查的热点地区之一,区内锂铍等稀有金属矿产资源优势突出,有望逐步发展成为国家级大型资源基地。作为长江上游生态保护屏障,该区生态环境脆弱,面对矿业开发的巨大机遇,在当前"环保优先"的现实情况下,急需摸清该区环境家底,支撑国家能源战略发展。本文用ICP-MS方法检测了该区352件土壤样品中7种重金属元素(Cd、As、Pb、Cr、Cu、Ni、Zn)的含量,运用地累积指数法、污染负荷指数法、潜在生态风险指数法和健康风险评价模型,结合GIS空间分析,综合研究了该区土壤中重金属的空间分布特征和生态风险。结果表明:(1)研究区土壤7种重金属元素浓度的平均值均没有超过国家农用土壤污染风险筛选值。As和Pb平均含量低于四川省土壤背景值,Cd、Cr、Cu、Ni和Zn含量高于背景值,分别是背景值的2.44、1.04、1.15、1.28和1.17倍。(2)Cd、Pb、Cr、Cu、Ni和Zn六种重金属元素浓度的空间分布特征明显受到区内黑云母花岗岩的影响,Pb的高浓度中心以及Cr、Cu、Ni和Zn的低浓度中心与岩体的空间位置对应关系明显。(3)地累积指数法评价结果显示,研究区土壤区域整体上不存在重金属异常累积;污染负荷指数法评价结果显示污染负荷指数均小于1,不存在重金属的污染;除Cd存在轻微的潜在生态风险外,其余6种元素均不存在潜在生态风险。(4)健康风险评价模型分析结果显示,空间上,Cd元素的单元素潜在生态风险指数空间分布规律与岩体存在一定联系,无生态风险区域与黑云母花岗岩岩体位置对应。土壤中的重金属可以通过手口、呼吸和皮肤直接接触三种途径进入人体,其中手口途径是产生健康风险的最主要途径。在全部重金属元素产生的健康风险中,除Cr的手口途径会产生可以接受的正常的自然致癌风险外,其余元素均不存在致癌性和非致癌性。研究表明,当前研究区土壤不存在重金属污染,潜在危害程度较低,且不存在非致癌和致癌性风险。但基于土壤中重金属存在一定的累积效应,在今后矿业开发过程中要密切关注土壤重金属浓度的变化,防止重金属污染带来的风险。 相似文献
19.
为了解垃圾填埋场周边地下水环境污染状况,以长沙市固体废弃物处理场周边土壤、地下水及下游水库水质为研究对象,对研究区进行采样分析,采用单因子污染指数法和内梅罗污染综合指数法对该垃圾填埋场周边环境重金属含量特征进行分析与风险评价。结果表明:As、Cr(Ⅵ)、Ni、Pb、Zn、Cu重金属是填埋场周边环境中的主要污染物,区域采样点及下游水库中重金属含量均值低于地下水质量标准Ⅲ类,填埋场区污染状况良好;Cr(Ⅵ)含量在ZK1与R1样品中均高于地下水质量标准Ⅲ类,是填埋场周边地下水的主要风险污染物;ZK1~ZK4中土壤重金属元素以Pb、Cr(Ⅵ)富集为主,其达中度污染程度,应引起重视。 相似文献
20.
依据云南省者竜—嘎洒地区土地质量地球化学调查数据,研究了表层土壤中Cr、Ni地球化学特征及主要影响因素,分析了农产品Cr、Ni含量特征。结果表明,研究区表层土壤中Cr、Ni含量受控于地质背景,光山—和平丫口岩体(σ)发育的土壤中Cr、Ni含量明显高于其他地层发育的土壤;不同类型土壤中Cr、Ni含量差异较大,且土地利用方式也会对土壤中Cr、Ni含量产生一定影响;研究区玉米、柑橘、茶叶、甘蔗、香蕉、核桃等农产品Cr、Ni含量均未超标,仅11件水稻Cr含量超过国家标准,占水稻样品总数的11.3%,区内农产品安全性总体较好;区内农用地(水田、旱地、园地、草地)面积为554.73km2,其中无风险(含量低于筛选值)面积为408.61km2,占比为73.66%,风险可控(含量在筛选值与管制值之间)面积为112.96km2,占比为20.36%,风险较高(含量>管制值)面积为33.16km2,占比为5.98%,土壤环境质量总体较好。针对部分土壤存在Cr、Ni污染风险问题,从水土保持、施肥方式、水旱轮作等角度提出了污染防控措施建议。 相似文献