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1.
填海工程会扰动滨海地区的环境平衡,导致区域地下水中多种重金属浓度的变化.为探明重金属浓度发生变化的确切原因,为最大限度减少填海工程对环境影响提供参考依据,本文以深港西部通道填海区为例,通过实验室模拟填海条件,研究了填海区重金属迁移的关键影响因素.结果表明,填海区地下水中Zn含量升高与地下水淡化、淤泥氧化过程及填料风化有关;Co、Mn含量升高则主要与填料风化释放有关;Pb则保持较稳定的状态. 相似文献
2.
以深港西部通道填海区淤泥为研究对象,研究了重金属的化学形态特征,分析了填海工程活动带来的填海区地下水物理化学条件变化对重金属各个形态的影响。结果表明:除残留态外,填海区重金属存在形态主要为铁锰结合态、碳酸盐结合态和硫化物及有机结合态,其中,Pb和Ni以铁锰氧化物结合态和碳酸盐结合态为主,Cu以碳酸盐结合态和有机结合态为主,Zn以有机结合态和铁锰氧化物结合态为主,而Cd则以碳酸盐结合态为主。各金属在深港西部通道填海区淤泥的潜在迁移能力序列如下:Pb(39.68%)>Cu(31.59%)>Zn(20.49%)>Cd(12.80%)>Ni(10.98%)。 相似文献
3.
《铀矿地质》2020,(5)
二连盆地的卫镜岩体被认为是二连盆地努和廷铀矿床的重要铀源,文章对卫镜岩体在风化条件下元素的活动性进行了分析,结果表明:风化样品的化学风化指数CIA值介于58.67～60.07,反映寒冷、干燥气候条件下低等化学风化程度。在半风化过程中,斜长石最先风化分解,Ca、 Na流失,钾长石相对稳定;在地表强风化条件下,钾长石风化分解明显,且原生含磷矿物分解释放P而淋失;黏土矿物的吸附作用导致Mg、 Ca在地表强风化条件下富集;Fe_2O_3~T、 FeO含量降低明显,更可能与磁铁矿和黄铁矿的氧化淋滤有关。H、 LOI、 S和C在强风化样品中含量明显降低,暗示风化条件为干燥氧化气候条件,卫镜岩体花岗岩风化过程中Ca、 K、 Mg、 Fe、 C、 S等元素容易迁移,P、 Mn、Na次之,而Ti、 Al属于稳定元素。铁族元素Cr、 Ni、 Ti及REE等微量元素保持稳定,Nb、 Ta、 Zr、Hf、 Th、 Y等高场强元素以及部分大离子亲石元素Pb、 Rb、 Be、 Li、 Sb一定程度富集,U、 V、 Sr明显迁出,且Zr/Hf、 Nb/Ta、 Th/Sc、 Zr/Nb等元素比值均发生变化,主要受风化条件下原生矿物分解释放和黏土矿物吸附相互制约的过程共同控制;不同样品稀土配分模式一致,但Y/Ho值明显高于新鲜岩石的值,可能主要与地表HCO_3~-含量丰富有关。在干旱氧化、富集HCO_3~-的化学风化条件下更容易导致U的淋滤迁出,为二连盆地铀成矿提供重要铀源。 相似文献
4.
填海造陆区普遍存在次生盐渍化、地下结构物腐蚀等生态环境问题,尤其在中国北方沿海地区年蒸发量远大于降雨量的水循环条件下,此类问题更为突出。在简要回顾了填海现状和发展趋势的基础上,总结了填海后地下水系统和土体环境的演变趋势,并分析了造成上述影响的主要原因。通过对比湿润地区与半干旱地区的气候差异,认为利用集雨措施来引导自然淡化过程从而构建长效淋盐机制是半干旱填海区盐渍化防治的关键。同时指出,因地制宜地规划土体结构、提升排盐能力和种植绿化植物,是搭建和维持填海造陆区健康稳定生态系统的必要之举。 相似文献
5.
《矿物岩石地球化学通报》2019,(5)
为探讨高度城市化对地下水重金属/类金属的影响,选取深圳市福田区浅层含水层为研究对象,于2016年1月在福田区采集水样,并测定了pH、氧化还原电位、主量离子、无机氮、总溶解性固体、电导率以及多种重金属/类金属浓度。对比山区与城区地下水的重金属/类金属浓度,可见城区地下水重金属/类金属普遍富集,其中Mn、Co、Ni、Cd浓度升高最为普遍。地下水重金属/类金属污染程度依次为MnTlSePbAs,其单因子污染指数均达到中度或重度污染;50%的城区地下水为重度污染。主成分分析表明,地下水中Se与Mo的升高与海水的入侵有关;Mn、Co、Ni的升高与城市建筑地基的溶解相关;Cu和Sb的升高与生活污水排放有关;Cd、Tl、Pb的升高可能与酸雨淋滤土壤有关。高度城市化是造成福田区地下水重金属和类金属富集的最主要因素,城市地基溶解的影响最为显著。 相似文献
6.
为探讨高度城市化对地下水重金属/类金属的影响,选取深圳市福田区浅层含水层为研究对象,于2016年1月在福田区采集水样,并测定了pH、氧化还原电位、主量离子、无机氮、总溶解性固体、电导率以及多种重金属/类金属浓度。对比山区与城区地下水的重金属/类金属浓度,可见城区地下水重金属/类金属普遍富集,其中Mn、Co、Ni、Cd浓度升高最为普遍。地下水重金属/类金属污染程度依次为Mn>Tl>Se>Pb>As,其单因子污染指数均达到中度或重度污染;50%的城区地下水为重度污染。主成分分析表明,地下水中Se与Mo的升高与海水的入侵有关;Mn、Co、Ni的升高与城市建筑地基的溶解相关;Cu和Sb的升高与生活污水排放有关;Cd、Tl、Pb的升高可能与酸雨淋滤土壤有关。高度城市化是造成福田区地下水重金属和类金属富集的最主要因素,城市地基溶解的影响最为显著。 相似文献
7.
通过重金属含量分析,分级提取化学形态分析,结合矿物成分和化学成分分析,对黄龙铺矿区1号尾矿库重金属元素在风化过程中的地球化学行为进行了研究。研究结果表明在横向上,尾矿库中心排水口处地势低洼,铜、铁因相对活泼易于迁移而流失,铅、锌、铬、镉在尾矿库四周的地表浅部淋失,在尾矿库中心则相对富集。化学形态分析表明尾砂中各重金属元素赋存状态各有不同,一般以T6原生硫化物态和T7残渣态为主,铜、锌、铁迁移性较强;其他则较弱,表明对环境威胁不是很大。重金属的迁移明显的分为氧化带和次氧化带,研究结果显示尾矿覆盖方法也不一定能够有效地阻滞污染元素的迁移。 相似文献
8.
岩石风化过程中的元素活动性评价除应考虑该元素在风化产物中残留与淋失状况及在淋滤液(地下水及室内浸泡液等)中的浓度外,还应考虑其在母岩中的相对含量.峨眉山玄武岩斜坡地下水及室内浸泡液中各元素原子个数比值与母岩中对应比值之间均存在显著差异,其造岩矿物的非全等溶解特征显著.综合考虑风化过程中的岩石成分变化、斜坡地下水及室内浸泡液化学成分确定的峨眉山玄武岩风化过程中的元素活动性顺序为Ca＞Na＞Mg≥Si＞K＞Fe.活动性强或惰性程度高、对风化程度变化响应敏感应成为岩石风化程度指示性元素的选择标准,Ca和Fe应成为峨眉山玄武岩风化程度评价的首选元素. 相似文献
9.
以江西省武宁县石门寺钨铜矿区燕山期和晋宁期岩体风化作用过程中W、Cu等元素的表生地球化学行为为研究对象,通过反映风化程度的化学风化指数CIA、风化作用过程中组分得失的估算、不同介质中W、Cu等成矿元素的含量变化及大离子亲石元素表生地球化学行为等方法的研究表明,石门寺钨铜矿区2个时期岩体元素淋失与风化强度有关,土壤剖面中碱金属、碱土金属元素大量淋失,而W、Cu等成矿元素在土壤B层中显著富集;从岩石到土壤、再到水系沉积物风化过程中,W、Cu等成矿元素含量逐渐升高,为此,一级水系沉积物和B层土壤是赣北九岭W、Sn、Cu、Mo多金属矿集区地球化学找矿的绝佳采样介质,是矿集区内找矿新突破的有效手段。 相似文献
10.
以江西省武宁县石门寺钨铜矿区燕山期和晋宁期岩体风化作用过程中W、Cu等元素的表生地球化学行为为研究对象,通过反映风化程度的化学风化指数CIA、风化作用过程中组分得失的估算、不同介质中W、Cu等成矿元素的含量变化及大离子亲石元素表生地球化学行为等方法的研究表明,石门寺钨铜矿区2个时期岩体元素淋失与风化强度有关,土壤剖面中碱金属、碱土金属元素大量淋失,而W、Cu等成矿元素在土壤B层中显著富集;从岩石到土壤、再到水系沉积物风化过程中,W、Cu等成矿元素含量逐渐升高,为此,一级水系沉积物和B层土壤是赣北九岭W、Sn、Cu、Mo多金属矿集区地球化学找矿的绝佳采样介质,是矿集区内找矿新突破的有效手段。 相似文献
11.
Coastal reclamation has been carried out along the coastal areas near Shenzhen, China in a large scale since 1980s by dumping
fill materials over the marine mud at the sea bottom. Usually the area to be reclaimed is drained first and some of the mud
is air-dried for a few weeks before it is buried by fill. After reclamation, the terrestrial groundwater, which is relatively
acidic and with high dissolved oxygen, gradually displaces the seawater, which is alkaline with high salinity. The changes
in the burial conditions of mud and the properties of the pore water in the mud may induce the release of some heavy metals
into the mud. Field survey confirms that the pH and salinity of the groundwater in the reclamation site are much lower than
the seawater. Chemical analyses of mud and groundwater samples collected from the reclamation sites reclaimed in different
years indicate that most of the heavy metals in the mud decrease gradually with time, but the heavy metals in the groundwater
are increased. The release of heavy metals into pore water due to reactivation of heavy metals in the mud is of environmental
concern. To understand why some of the heavy metals can be released from the mud more easily than others, a sequential extraction
method was used to study the operationally determined chemical forms of five heavy metals (Cu, Ni, Pb, Zn, and Cd) in the
mud samples. Heavy metals can be presented in five chemical forms: exchangeable, carbonate, Fe–Mn oxide, organic, and residual.
Ni and Pb were mainly associated with the Fe–Mn oxide fraction and carbonate fraction; Zn was mainly associated with organic
fraction and Fe–Mn oxide fraction, while Cu and Cd were associated with organic fraction and carbonate fraction, respectively.
If the residual fraction can be considered as an inert phase of the metal that cannot be mobilized, it is the other four forms
of heavy metal that cause the noticeable changes in the concentration of heavy metals in the mud. On the basis of the speciation
of heavy metals, the mobility of metals have the following order: Pb (36.63%) > Cu (31.11%) > Zn (20.49%) > Ni (18.37%) > Cd
(13.46%). The measured metal mobility fits reasonably well with the degree of concentration reduction of the metals with time
of burial observed in the reclamation site. 相似文献
12.
A large part of the Sydney 2000 Olympic Site at Homebush Bay was reclaimed over several decades using an estimated 9 Mt of domestic, commercial and industrial waste. Past activities, such as reclamation of wetlands, land clearing, shoreline remodelling and industrial practices, have caused an adverse environmental impact on the Homebush Bay site. Core samples (n = 4513) collected from the reclaimed lands of Homebush Bay show that, prior to remediation, soil contaminated by heavy metals (Cr, Cu, Pb, Zn) may have posed a threat to groundwater in the area. Mean Pb concentrations from the three land types at the Olympic site range from 65 to 374 μg/g in reclaimed areas, 78–167 μg/g in landfill areas and 44–52 μg/g in non‐infilled areas, respectively. Heavy‐metal concentrations in soils from non‐infilled areas indicate that these parts of the site were uncontaminated. The distribution of heavy metals in soil samples revealed a close association between elevated concentrations and the presence of fill materials at the site. Metal concentrations were frequently above Australian and New Zealand Guidelines for Fresh and Marine Water Quality. The Olympic Coordination Authority's remediation strategy to clean up the Homebush Bay site included consolidating contaminated waste into landscaped hills, which were capped with impermeable clay and thermal destruction of scheduled waste on site. The primary aims of the current study were to provide a scientific foundation for the remediation/rehabilitation of natural systems, and to make a contribution to the Olympic Coordination Authority's Development Plan and Environmental Management System for the site. 相似文献
13.
The Tinto and Odiel rivers drain 100 km from the Rio Tinto sulphide mining district, and join at a 20-km long estuary entering the Atlantic Ocean. A reconnaissance study of heavy metal anomalies in channel sand and overbank mud of the river and estuary by semi-quantitative emission dc-arc spectrographic analysis shows the following upstream to downstream ranges in ppm (μg g?1): As 3,000 to <200, Cd 30 to <0.1, Cu 1,500 to 10, Pb 2,000 to <10, Sb 3000 to <150, and Zn 3,000 to <200. Organic-rich (1.3–2.6% total organic carbon, TOC), sandysilty overbank clay has been analyzed to represent suspended load materials. The high content of heavy metals in the overbank clay throughout the river and estuary systems indicates the importance of suspended sediment transport for dispersing heavy metals from natural erosion and anthropogenic mining activities of the sulfide deposit. The organic-poor (0.21–0.37% TOC) river bed sand has been analyzed to represent bedload transport of naturally-occurring sulfide minerals. The sand has high concentrations of metals upstream but these decrease an order of magnitude in the lower estuary. Although heavy metal contamination of estuary mouth beach sand has been diluted to background levels estuary mud exhibits increased contamination apparently related to finer grain size, higher organic carbon content, precipitation of river-borne dissolved solids, and input of anthropogenic heavy metals from industrial sources. The contaminated estuary mud disperses to the inner shelf mud belt and offshore suspended sediment, which exhibit metal anomalies from natural erosion and mining of upstream Rio Tinto sulphide lode sources (Pb, Cu, Zn) and industrial activities within the estuary (Fe, Cr, Ti). Because heavy metal contamination of Tinto-Odiel river sediment reaches or exceeds the highest levels encountered in other river sediments of Spain and Europe, a detailed analysis of metals in water and suspended sediment throughout the system, and epidemiological analysis of heavy metal effects in humans is appropriate. 相似文献
14.
Regional distribution pattern of groundwater heavy metals resulting from agricultural activities 总被引：18，自引：0，他引：18
Contaminations of groundwater by heavy metals due to agricultural activities are growing recently. The objective of this study
was to evaluate and map regional patterns of heavy metals (Cd, Zn and Cu) in groundwater on a plain with high agricultural
activities. The study was conducted to investigate the concentration of heavy metals and distribution in groundwater in regions
of Shush Danial and Andimeshk aquifers in the southern part of Iran. Presently, groundwater is the only appropriate and widely
used source of drinking water for rural and urban communities in this region. The region covers an area of 1,100 km2 between the Dez and Karkhe rivers, which lead to the Persian Gulf. For this study, the region was divided into four sub-regions
A, B, C and D. Additionally, 168 groundwater samples were collected from 42 water wells during the earlier months of 2004.
The flame atomic absorption spectrometry (AAS-Flame) was used to measure the concentration of heavy metals in water samples
and the Surfer software was used for determination of the contour map of metal distribution. The results demonstrated that
in all of the samples, Cd and Zn concentrations were below the EPA MCLG and EPA secondary standard, respectively. However,
the Cu contents of 4.8 % of all samples were higher than EPA MCL. It is also indicated that the concentrations of metals were
more pronounced at the southern part of the studied region than at the others. The analysis of fertilizers applied for agricultural
activities at this region also indicated that a great majority of the above-mentioned heavy metals were discharged into the
environment. Absence of confining layers, proximity to land surface, excess agricultural activities in the southern part and
groundwater flow direction that is generally from the north to the southern parts in this area make the southern region of
the Shush plain especially vulnerable to pollution by heavy metals than by other contaminants. 相似文献
15.
滇西沘江流域水体中重金属元素的地球化学特征 总被引：6，自引：1，他引：5
通过测定流经兰坪金顸铅锌矿区的沘江水体中Pb、Zn、Cd、As的含量和底泥中重金属元素的化学形态的含量,分析了重金属元素的分布和化学形态的变化。结果表明,沘江水遭到了Cd污染,底泥已经成为重金属元素的蓄积库,以国家土壤环境质量标准（Ⅲ级）衡量,Pb、Zn、Cd和舡分别超标3．4倍、15．8倍、106倍和2．6倍。沘江水中重金属元素含量的峰值在矿山附近的下游,而底泥中重金属元素的峰值在矿山下游30-50km的地方,矿业活动、水流变缓、pH等水体环境条件的变化都能影响水和底泥中重金属元素的含量。底泥中的Pb以碳酸盐结合态为主,Zn和Cd以铁锰氧化物结合态为主,而As以残渣态为主。Pb、Cd、Zn三种元素的环境有效态含量比较高,对沘江流域生态环境具有潜在的巨大的危害。 相似文献
16.
研究矿业活动重金属的释放、迁移及累积特征对于控制和治理矿区水土环境污染具有重要的意义。本文通过广东大宝山矿区水土污染源调查及横石河流域沿岸水土样品采集,以研究区土壤对照值及国家环境质量为标准,试图探讨了大宝山矿区重金属迁移及累积特征。研究结果表明,横石河沿岸土壤重金属元素主要来自采矿活动的酸性废水的排放,土壤中Cd、Pb、Cu和Zn的含量均超过对照值,呈现出明显的累积特征,且Cd、Cu含量超过了国家土壤环境质量标准;土壤中重金属累积程度及其风险等级呈现出从源头向下游递减的特点,其中凉桥、水楼下地段农田重金属处于高风险区,阳河-莲心村虽有累积,但无风险;上坝村地处土壤重金属累积的中风险区,下坝村处于低风险区。研究结果为矿区重金属污染防治提供了重要依据。 相似文献
17.
河口沉积物—水界面重金属生物地球化学研究进展 总被引：15，自引：1，他引：15
河口区既是人类排污物的主要汇集地，又是单向流体和双向流体相互作用的场所，三者构成一个复杂而多变的地球化学物理场。在这里因一定的物理，化学和生物化学作用使来自陆地的重金属污染物从水体中沉降下来，进入底部沉积物即积累过程，又会因类似的作用使这些金属从沉积物中活化而再次进入水体即释放过程，产生所谓的“二次污染”，河口沉积物水界面过程调控着这一体系的方向与限度。 相似文献
18.
珠江三角洲污灌区地下水重金属含量及其相互关系 总被引：7，自引：0，他引：7
为了解污灌区地下水重金属含量特征,采集地表水样5组、地下水样14组进行化学组分定量分析。结果表明：污灌区地下水8种重金属元素中,仅有Ni和As两种元素超标,超标率分别为14.3％和42.9％。8种重金属含量在污灌区地表水、工厂废水以及地下水中存在明显的对应关系。Ni、Zn、Se、Cd这4种元素间存在显著或极显著的正相关关系,Cu与Pb和Cd分别呈极显著和显著的正相关关系,Cr仅与Ni呈显著的正相关关系,As与其它7种元素的相关性均不明显。聚类分析结果显示8种重金属可分为4类：Pb和Cu一类,Se、Cd、Ni、Zn一类,Cr和As均单独一类。Pb和Cu与Fe的相似性最好,Se、Cd、Ni、Zn与Mg2+存在较好的相似性,Cr与HCO－3的相似性最好,As与SO2－4存在一定的相似性。 相似文献