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A geochemical assessment of the middle and lower Mvoti river system,KwaZulu-Natal,South Africa 总被引：1，自引：1，他引：0
This paper presents one of the first investigations into the geochemical enrichment of the middle and lower Mvoti river system.
Chemical elements are naturally present in aquatic sediments, but their concentrations tend to rise to potentially toxic levels
via both natural and anthropogenic processes. This study evaluated the concentrations of aluminum, arsenic, boron, barium,
cadmium, calcium, cobalt, chromium, copper, iron, lead, magnesium, manganese, molybdenum, nickel, phosphorous, selenium, silicon,
strontium, titanium, vanadium and zinc, using inductively coupled plasma optical emission spectroscopy. The levels of elements
present were used to assess their spatial distribution within the river and to determine the contamination factors and enrichment
factors for each element. The pollution load index (PLi) is another contributing parameter that was calculated to determine
the degree of pollution at each site. The results indicate that the sediments of the Mvoti are low to moderately polluted
and deteriorating with time (average PLi value of 5.19), and that a major contributing factor to this contamination is natural
sources. 相似文献
3.
Analysis of ten heavy metals (Ag, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Zn) in six sediment cores from Wellington Harbour show both anthropogenic enrichments and diagenetic modifications. Absolute concentrations determined by two methods, x-ray fluorescence and acid leaching for bioavailability, are not comparable. However, vertical trends in concentrations of the cored sediment are comparable. To assess levels of anthropogenic pollution, enrichment factors (enriched concentrations in upper core divided by background levels in lower core) are preferred over index of accumulation (I
geo) values because preindustrial or background levels of heavy metals are well constrained. The ten metals are placed into three groups: (1) Cu, Pb, and Zn, which show the most anthropogenic enrichment; (2) As, Cd, Cr, Ni, and Sb, which are often associated with anthropogenic pollution but show only minor enrichment; and (3) Fe and Mn, which are diagenetically enriched. Assuming harbor waters are well mixed, anthropogenic enrichments of Cu, Pb, and Zn, are time correlative, but the degree of enrichment depends on the method of analysis and core location. Levels of As, Cd, Pb, and Zn show small variations in preindustrial sediments that are not related to changes in grain size and probably result from changes in the oxidation-reduction potential of the sediments and salinity of the pore waters. 相似文献
4.
Alan M. Shiller Joris M. Gieskes N. Brian Price 《Geochimica et cosmochimica acta》1985,49(5):1239-1249
Particulate Fe and Mn may be important trace metal scavengers in the water column as well as being probable indicators of biologically mediated redox processes. A study has been made of suspended particulate composition in the Santa Barbara Basin, a shallow near-shore basin off southern California with sub-oxic conditions below sill depth. Observations have revealed several interesting phenomena relating to the geochemistry of Fe and Mn. Most striking is a profound enrichment of particulate Fe in samples from the bottom two hundred meters. These particulates have a constant Fe/P mole ratio of about three and may originate at the sediment-water interface or may be transported to the basin from local marshes. For particulate Mn, enrichments are observed both in the sub-sill waters and near the base of the euphotic zone. A consideration of particle removal rates suggests that the sub-photic zone enrichment has a biogenic origin. In the sub-sill waters, enrichment in Mn is apparently due to the precipitation of dissolved Mn diffusing from the anoxic basin sediments. A simple mass balance suggests that most of the Mn lost from the sediments is transported from the Santa Barbara Basin in dissolved form. 相似文献
5.
Alicia Kirschbaum Jesica Murray Emilce López Ahinoam Equiza Marcelo Arnosio Geraldo Boaventura 《Environmental Earth Sciences》2012,65(2):493-504
The Yacoraite River and its tributaries run down the eastern slope of the Aguilar Range. It is one of the tributaries of the
Rio Grande, located in Quebrada de Humahuaca, a UNESCO World Heritage site. The Aguilar underground mine (Pb–Ag–Zn) is located
in the upper reaches of the Yacoraite River drainage basin. The aim of this work is to characterize the presence of heavy
metals in water and sediments of the Yacoraite River and to identify their sources. The analysis shows the seasonal variation
of heavy metals concentration in water and their relation with the World Health Organization (WHO) limits established for
human consumption. The Yacoraite basin is naturally anomalous in some metals and some elements, such as As which is controlled
by the chemical composition of regional lithology. During the wet season, Al, Co, Mo and Pb concentrations in water samples
are higher than during the dry season; in addition, these metals are also higher than WHO limit values. High enrichment factors
for Ba, Mo, Pb, Zn and Cd were found in Casa Grande stream, indicating the direct influence of the mining activities. Cd,
Pb and Zn are present in the Aguilar ore minerals, such as sphalerite and galena. Sediments collected during the dry season
show a drastic increase in the concentration of As, Pb, Ba, Zn, Cd and Mn. The Müller geo-accumulation index in Casa Grande
indicates that it is a highly polluted stream. The concentrations of As, Pb, Ba, Zn, Cd are also high in Yacoraite River: Security Quality Guidelines indicates
toxicity. A decrease in enrichment factors and geo-accumulation indices observed in sediments indicates the occurrence of precipitation/adsorption
processes in the river to restore the equilibrium composition. Strict environmental controls in Aguilar Mine are necessary
to avoid the uncontrolled input of toxic metals in Casa Grande stream and Yacoraite River. 相似文献
6.
M. A. Levitan Yu. P. Girin V. L. Luksha I. V. Kubrakova I. A. Roshchina B. Sattler O. A. Tyutyunnik M. Yu. Chudetskii 《Geochemistry International》2011,49(5):459-481
The paper presents data on the geographic and geological conditions of modern sedimentation in Lake Untersee, the largest
lake in East Antarctica. Geochemical and sedimentation data indicate that the leading mechanism providing Al-Si sedimentary
material to the surface layer of the bottom sediments is the seasonal melting of the Anuchin glacier and the mountain glacier
on the southeastern face of the valley hosting the lake. The strongly reduced conditions in the lowermost 25 m of the water
column in the smaller of the two depressions at the lake bottom were favorable for the enrichment of the bottom sediments
in bacteriogenic organic matter, Mo, Au, and Pd. The H2S-contaminated water facilitates the significant enrichment of the sediments only in redox-sensitive elements able to migrate
in the form of anionic complexes and precipitate (coprecipitate) as sulfides. 相似文献
7.
Surface sediment samples from near-shore shallow water as well as deeper water locations N and NE of the island of Methana were investigated geochemically. Shallow water samples from Thiafi Bay reveal up to 38-fold enrichment of As, associated with elevated contents of Sb, Fe and Zn. Deeper water samples NE of Methana show moderate Mn enrichment accompanied with elevated trace metal concentrations of As and, in some samples, Cd and Cu. In an area, where small mounds of possible hydrothermal origin were observed on the sea floor, fine-grained Fe-rich sediment was sampled with enrichment of typical hydrothermal trace elements As, P and Sb. Element enrichment in the investigated areas off Methana corresponds in terms of absolute concentrations and element suite to comparable hydrothermally influenced sediments from other locations of the Hellenic volcanic arc. The region between Methana peninsula and Aegina Island is not marked by vigorous hydrothermal activity, but localised enrichments of Fe and/or Mn, As, Sb as well as associated trace elements typically found in hydrothermally influenced sediments were identified. 相似文献
8.
Assessment of the anthropogenic influx of metallic pollutants in Yarmouk River, Jordan 总被引：2，自引：0，他引：2
Chemical data for 15 elements at depths at 10-cm intervals in 6 cores at two locations along the Yarmouk River as well as
the heavy-metal enrichment factors (EFs) and anthropogenic factors (AFs) show that Cd and Ni for all the cores, and Mn, Zn,
Cr, Co and Pb for core 3 at location A are anthropogenically enriched. The contents of these elements decrease clearly with
depth in the sediment column. The sequence of element enrichment depends on whether the EF and the AF are used to calculate
the elements which show no systematic decrease in enrichment with depth in all cores, especially for location A, probably
due mainly to a higher sedimentation rate. The results of the present study show that the sediments of the Yarmouk River are
uncontaminated with Fe, Cr, and Mn, whereas they are uncontaminated to moderately contaminated with Ni, Co, and Zn, moderately
contaminated with Pb, and strongly to extremely contaminated with respect to Cd. Also, the study shows that the EF and AF
values are higher than 1, which indicates that all the metals measured in the sediments of the Yarmouk River were enriched
by various anthropogenic sources in the catchment area of this river. Heavy metal enrichment reflects the combined effects
of agricultural activities, a treatment plant, a landfill site at El-Akader, and small industries in the region.
Received: 16 March 2000 · Accepted: 12 August 2000 相似文献
9.
The fractionation of P in Pandoh Lake surface sediments has been investigated for the first time in order to understand its environmental availability and sources, and the eutrophication status of this lake. Inorganic-P is present mainly as authigenic-P (step-III). The authigenic P concentration is higher in winter relative to the summer and monsoon seasons and ranged from 35.9 to 46.9 μg/g. The loosely sorbed or exchangeable-P (step-I), Fe(III)-bound-P (step-II) and detrital inorganic-P (step-IV) were higher in the monsoon season and varied from 3.70 to 11.1 μg/g, 16.9 to 32.0 μg/g and 9.89 to 17.0 μg/g, respectively. Organic-P reached a maximum in the summer season and ranged from 8.00 to 14.9 μg/g. Authigenic-P and detrital inorganic-P show seasonal changes, as pH influences the interaction between P and CaCO3 in the water column. In the winter season, phosphate is precipitated out of the water column and fixed in the sediments as a result of an increase in pH. Calcite-bound-P in the sediments may be redissolved by decreasing pH in the summer season. Relatively high rates of mineralization during the monsoon results in the seasonal pattern of organic-P fractionation to sediment as follows: monsoon = winter < summer. Iron, Ca, organic matter and silt and clay contents seem to play a significant role in regulating the seasonal P budget. Principal component analysis (PCA) was used to identify the factors which influence sedimentary P in the different seasons. 相似文献
10.
Spatio-temporal dynamics of heavy metals in sediments of the river estuarine system: Mahanadi basin (India) 总被引：1，自引：1，他引：0
Sanjay Kumar Sundaray Binod Bihari Nayak Byeong-Gweon Lee Dinabandhu Bhatta 《Environmental Earth Sciences》2014,71(4):1893-1909
Dynamics of heavy metals in the surface sediments of Mahanadi river estuarine system were studied for three different seasons. This study demonstrates that the relative abundance of these metals follows in the order of Fe > Mn > Zn > Pb > Cr > Ni ≥ Co > Cu > Cd. The spatial pattern of heavy metals supported by enrichment ratio data, suggests their anthropogenic sources possibly from various industrial wastes and municipal wastes as well as agricultural runoff. The metal concentrations in estuarine sediments are relatively higher than in the river due to adsorption/accumulation of metals on sediments during saline mixing, while there is a decreasing trend of heavy metal concentrations towards the marine side. The temporal variations for metals, such as Fe, Mn, Zn, Ni and Pb exhibit higher values during monsoon season, which are related to agricultural runoff. Higher elemental concentrations are observed during pre-monsoon season for these above metals (except Ni) at the polluted stations and for metals, such as Cr, Co and Cd at all sites, which demonstrate the intensity of anthropogenic contribution. R-mode factor analysis reveals that “Fe–Mn oxy hydroxide”, “organic matter”, “CaCO3”, and “textural variables” factors are the major controlling geochemical factors for the enrichment of heavy metals in river estuarine sediment and their seasonal variations, though their intensities were different for different seasons. The relationships among the stations are highlighted by cluster analysis, represented in dendrograms to categorize different contributing sites for the enrichment of heavy metals in the river estuarine system. 相似文献
11.
To investigate the distribution pattern and controlling factors of rare earth elements (REEs) in riverine sediments, river mouth sediments were collected at five geographically different rivers around the Yellow Sea. Two- (1 M HCl leached and residual fractions) and five-step sequential extraction schemes (the SEDEX method) were applied to size-separated sediments < 20 µm. For the total REE composition, patterns normalized relative to the upper continental crust (UCC) showed light REE (LREE) and middle (MREE) enrichments in the Korean river sediments and MREE enrichment in the Chinese river sediments. LREE and MREE enrichments in 1 M HCl leached fractions played a major role in the distribution patterns of the total compositions in all the river sediments. About half of LREE enrichment in Korean river sediments was explained by the residual fraction. Comparison of the REE composition with major elements (Al, Fe, Ca, P) in each fraction of the SEDEX scheme revealed that MREE enrichment could be explained by reactive iron minerals, including goethite and hematite, although REE/Fe ratios showed different trends among the rivers due to different major REE-host iron minerals. After extracting reactive irons, authigenic phosphate, and carbonate, the sequential 1 M HCl fraction indicated that LREE enrichment in Korean river sediments may have originated from clay minerals, such as chlorite. These observations suggest that LREE enrichment may be a good tracer, while MREE enrichment should be used cautiously considering diagenetic modification, when using the REE composition to identify the sources of terrestrial materials. 相似文献
12.
Manganese ores of Nishikhal occur as distinctly conformable bands in the khondalite suite of rocks belonging to the Precambrian
Eastern Ghats complex of south Orissa, India. Manganese minerals recorded are cryptomelane, romanechite, pyrolusite, with
minor amounts of jacobsite, hausmannite, braunite, lithiophorite, birnessite and pyrophanite. Goethite, graphite, hematite
and magnetite are the other opaque minerals and quartz, orthoclase, garnet, kaolinite, apatite, collophane, fibrolite, zircon,
biotite and muscovite are the gangue minerals associated with these ores. The mineral chemistry of some of the phases, as
well as the modes of association of phosphorous in these ores have been established. The occurrence of well-defined bands
of manganese ore; co-folding of manganese ore bands and associated metasedimentary country rocks; the min-eral assemblage
of spessartite-sillimanite-braunite-jacobsite-hausmannite; the geochemical association of Mn-Ba-Co-Ni-Zn together with the
Si versus Al and Na versus Mg plots of the manganese ores suggest that the Nishikhal deposit is a metamorphosed Precambrian
lacustrine deposit. Continental weathering appears to be the source for manganese and iron. After deposition and probable
diagenesis, the manganese-rich sediments were metamorphosed along with conformable psammitic and pelitic sediments under granulite
facies conditions, and subsequently underwent supergene enrichment to produce the present deposit.
Received: 14 March 1995 / Accepted: 11 April 1996 相似文献
13.
基于LA-ICP-MS多元素成像技术的早寒武世磷结核成因研究 总被引：3，自引：3，他引：0
我国下寒武统底部广泛发育磷结核、磷块岩等富磷沉积,为早寒武世最为重要的化学标志层之一,也代表了隐生宙—显生宙转折期地球表层系统的重大变革。当前对磷来源和富集机制的解释不一。为进一步明确该时期富磷沉积的形成机制,本文利用激光剥蚀电感耦合等离子体质谱联用技术(LA-ICP-MS)对贵州金沙地区牛蹄塘组黑色页岩中的磷结核进行多元素原位微区成像研究。结果表明:磷结核中各元素富集情况清晰地记录了磷结核形成过程中微环境的变化趋势。其中,磷结核内部Ca、P共富集以及Si亏损,指示P富集缘于自生磷灰石生成,P则来自于有机质含氧或厌氧降解释放;Mn、Zn与P共富集于磷结核内部,指示结核形成时的底部水体为含氧水体;As、Mo、V等元素主要富集于围岩或黑色页岩,指示缺氧含H_2S水体形成终止了结核生长。本研究显示,LA-ICP-MS原位多元素成像技术能够获取微区内丰富的地球化学信息,并提供高精度可视化证据,未来将在地质勘探和古环境研究等领域得到更广泛应用。 相似文献
14.
To evaluate the magnitude of variation in grain size distribution in the Krishna river, bed sediments and suspended sediments collected along the length of the river have been studied. There are both temporal and seasonal variation in the grain size distribution of suspended sediments. The statistical parameters show the change along the river in a non-linear fashion which may be due to human interference and due to different types of sediments contributed by tributaries to the Krishna river. The suspended sediments are mostly fine silt (4 to 16m), poorly sorted, showing coarse to fine skewed and are platyto leptokurtic. The bed sediments are mostly medium sand (350m) showing moderate to well sorted, coarse to fine skewed and are platy- to leptokurtic. The CM diagram of Krishna river bed sediments suggests that deposition takes place by (1) rolling (2) rolling and suspension and (3) graded suspension. The suspended sediments represent deposits of uniform suspension. 相似文献
15.
The Mullipallam creek in Muthupet mangroves region is the only E-W trending coastal strip in the SE coast of India and is
very important, as the mangrove acts as a barrier to natural diasters. Natural, anthropogenic signals and accumulation of
elements were made by collecting sediment samples at various depths in a core. All sediments were analyzed for carbonates
(CaCO3), organic carbon (OC), major (Si, Al, Fe, Na, K, Ca, Mg, P), and trace (Mn, Cr, Cu, Ni, Co, Pb, Zn). Normalization with Al
values has been done for all the major and trace elements and enrichment factors have been calculated. The calculated enrichment
factors and comparison indicate that the trace metals (especially Pb) are enriched mainly due to the external (anthropogenic)
activities in the land as well as in the coastal zone (Palk Strait). 相似文献
16.
黑色岩型铂族矿物中铂钯金相态ICP-MS分析方法研究 总被引：4，自引：4，他引：0
黑色岩是近年发现的铂族元素重要载体,由于其金属来源的多样性及成矿作用的复杂性,对于铂族元素在该类矿物中的分布及富集形式目前并不十分清楚,这也是造成黑色岩中铂族元素测定不稳定的主要原因。本文根据黑色岩的矿物性质及组成,将黑色岩中Pt、Pd、Au的赋存状态划分为:可交换相、有机结合相、硫化物结合相、残渣相。通过应用硫氰酸钾+氰化钠作为解吸剂,有效抑制了黑色岩中有机碳对各相态中Pt、Pd、Au的吸附,采用分离富集ICP-MS法测定了Pt、Pd、Au在各相态中的分布。结果表明:(1)各元素各相态的提取总量与该元素在样品中的总量之比分别为Pt 94.4%~101.0%,Pd 95.8%~101.0%,Au 96.7%~102.0%,说明本方法具有较好的准确性和重现性;(2)黑色岩矿物中Pt、Pd、Au的富集不仅具备亲硫性,而且与有机碳形成的地质条件、地质背景有明显的相关性,此结果为研究黑色岩中铂族元素所处的地球化学环境及其成矿规律提供了重要信息。 相似文献
17.
Nutrient limitation of the rhizophytic macroalgaPenicillus capitatus found associated with subtropical seagrass meadows in Bermuda was determined from enrichment assays and subsequent tissue analyses. The photosynthetic response ofP. capitatus to additions of inorganic nitrogen (N) or phosphorus (P), measured as oxygen evolution in closed incubation chambers, increased significantly in both the 16 h and 6 d experiments only with nitrogen enrichment. The average photosynthetic response for all treatments was virtually identical in the two experiments, indicating that there was not a significant time lag in nutrient uptake and that the short term (16 h) assay accurately reflected the longer term (6 d) photosynthetic response to nutrient enrichment. Average tissue nitrogen levels for the nitrogen-treated algae were 29% higher than the phosphorus-treated algae and 18% greater than the controls, corroborating the results from the photosynthesis assay.P. capitatus may acquire nutrients directly from sediment sources via rhizoid holdfasts. Ratios of total dissolved nitrogen (TN) to total dissolved phosphorus (TP) in pore water at 10 and 20 cm depths (6.1 and 4.5, respectively) indicate a nitrogen-limited nutrient pool. These low pore water TN:TP ratios may be a function of a limited sorptive capacity of the calcium carbonate sediments for phosphate, anthropogenic nutrient inputs, or high rates of denitrification, all of which would induce N rather than P limitation in these carbonate-rich sediments. 相似文献
18.
As a result of over-erosion of soils, the fine particles, which contain the majority of nutrients, are easily washed away from soils, which become deficient in a host of components, accumulating in lakes. On one hand, the accumulation of nutrients-rich sediments are a problem, as they affect the quality of the overlying water and decrease the water storage capacity of the system; on the other hand, sediments may constitute an important resource, as they are often extremely rich in organic and inorganic nutrients in readily available forms. In the framework of an extensive work on the use of rock related materials to enhance the fertility of impoverish soils, this study aimed to evaluate the role on the nutrients cycle, of particles recycling processes from the watershed to the bottom of a large dam reservoir, at a wet tropical region under high weathering conditions. The study focus on the mineralogical transformations that clay particles undergo from the soils of the drainage basin to their final deposition within the reservoir and their influence in terms of the geochemical characteristics of sediments. We studied the bottom sediments that accumulate in two distinct seasonal periods in Tucuruí reservoir, located in the Amazonian Basin, Brazil, and soils from its drainage basin. The surface layers of sediments in twenty sampling points with variable depths, are representative of the different morphological sections of the reservoir. Nineteen soil samples, representing the main soil classes, were collected near the margins of the reservoir. Sediments and soils were subjected to the same array of physical, mineralogical and geochemical analyses: (1) texture, (2) characterization and semi-quantification of the clay fraction mineralogy and (3) geochemical analysis of the total concentration of major elements, organic compounds (organic C and nitrogen), soluble fractions of nutrients (P and K), exchangeable fractions (cation exchange capacity, exchangeable bases and acidity) and pH(H2O).There is a remarkable homogeneity in the sedimentary distribution along the reservoir in terms of the texture and mineralogy of the clay fraction and of the chemistry of the total, soluble and exchangeable phases. These observations contrast with the physical, morphological and chemical heterogeneity of the soils and the setting lithology. Most of the sediments has a higher contribution of fine-grained material and the mineralogy of the clay fraction is dominated by kaolinite in soils and kaolinite and illite in sediments, followed by lesser amounts of gibbsite, goethite, and metahaloisite and by small/vestigial contents of chlorite and smectite. The sediments are mainly inherited from the watershed but there exist marked differences between the accumulated sediments and their parent materials. These differences mainly come from the selective erosion of fine-grained particles and the extreme climatic conditions which enhance complex transformations of mineralogical and chemical nature. Compared with the parental soils, the reservoir sediments show the following differences: (1) enrichment in fine-grained and less dense inorganic particles, (2) aggradative mineralogical transformations, including enrichment in clay minerals with higher cationic adsorption and exchange capacity, (3) degradation of the crystalline structure of Fe- and Al-oxides (goethite, gibbsite), (4) increase in easily leached elements (Mg, Ca, P, K, Na) and decrease in chemically less mobile elements (Si, Fe) and (5) higher contents of organic carbon, nitrogen, and soluble forms of P and K, mainly concentrated in the clay fraction. These transformations are extremely important in the nutrients cycle, denoting that sediments represent an efficient sink for nutrients from the over-erosion of soils. Mineral and organic compounds can permanently or temporarily sequester these nutrients, recycling them and enhancing their availability through the slow release of components from relatively loose crystal structures. These processes can easily explain the enrichment in soluble and exchangeable forms of elements such as P, K, Ca or Mg. This study conclude that the particles recycling in a large tropical dam reservoir which receives high fluxes of allochthonous nutrients, has an important role in the good quality of sediments for agricultural use and in the profitable use of this technology to recover depleted soils in remediation projects in regions near large hydroelectric plants. 相似文献
19.
震旦系陡山沱组磷块岩的成岩作用和成岩环境 总被引：1，自引：0，他引：1
单满生 《吉林大学学报(地球科学版)》1987,(2)
本文重点讨论了磷块岩的成岩作用及其与沉积环境的联系,进而提出了磷块岩成岩环境的五个序列。各成岩自然序列,具有各自独岩的成岩作用特点,代表着不同成岩作用环境。不同成岩环境又与不同的磷酸盐相和沉积环境有关,且在很大程度上依赖于原始沉积及其环境的发展和演化。 探讨磷块岩成岩作用必须考虑到成岩作用发生过程的地质历史演化和条件,必须联系其环境背景。 相似文献
20.
季风性波动引起的降雨、径流和排泄过程会引发浅层地下水系统周期性氧化还原动态变化,从而对地下水系统中有害组分的迁移转化产生影响。为探讨氧化还原动态过程对沉积物中砷(As)和氟(F)释放的影响,本研究选择河北白洋淀地区沉积物样品,利用发酵罐作为反应器,建立氧化还原动态实验体系,并监测动态变化过程中实验体系各组分含量的变化。结果表明,碱性和还原环境均有利于地下水中As、F的富集。还原阶段较高的pH条件有利于溶液中F-的解吸,且体系中有机物降解会产生大量HC03-和C032-,与F-发生竞争吸附而有利于F-的富集。对于溶液中As的富集,一方面是由于还原条件下体系中的As以As(III)为主,受沉积物的吸附作用较弱,从而有利于As被释放到溶液中;另一方面是因为还原阶段较高的pH也会使反应体系中As和沉积物间的吸附作用被减弱,造成As的解吸附。由于实验所用沉积物砷含量较低,不同S042-浓度条件对氧化还原动态过程中As、F迁移的影响不明显。总之,氧化还原动态变化过程会强烈影响地下水系统中砷、氟的富集。 相似文献