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1.
An evaluation of metal bioaccessibility in estuarine sediments using the commercially available protein, bovine serum albumin 总被引：2，自引：0，他引：2
The bioaccessibility of metals (Al, Ca, Fe, Mn, Ag, Cd, Co, Cu, Ni, Pb, Sn, Zn) in oxic estuarine sediments has been evaluated using solutions of a commercially available protein (bovine serum albumin; BSA) that mimic the chemical conditions encountered in the gut environment of many deposit-feeding organisms. Over a 20 h incubation period with 5 g L− 1 BSA, metal mobilisation was generally biphasic in that a relatively short period of rapid release was succeeded by more gradual release or approach to equilibrium, although in some cases metal readsorption was evident during the time-courses. Availability to BSA, defined as metal released after 20 h relative to metal extracted by boiling aqua regia, was greatest for Cd, Ni, Ca and Zn and lowest for Fe and Mn, and correlated well with, but was an order of magnitude lower than, metal digested by acidified hydrogen peroxide. Time-courses conducted in the absence of the protein revealed that significant quantities of Ca and Mn were water-soluble, reflecting the partial dissolution of carbonates and hydrous Mn oxides, respectively. Additional experiments indicated a net increase in metal release with increasing BSA concentration and, with the exception of Ca and Mn, a substantial increase in metal mobilisation after sediment organic matter had been digested by peroxidation. These observations suggest that, apart from Ca and Mn, metal release proceeds via complexation with component amino acids of the protein, denudation of organic host phases, and exposure of inorganic, metal-bearing minerals. Accordingly, the bioaccessibility of a metal is predicted to be dependent on its (i) affinity for proteinaceous ligands, (ii) association with components of digestible sediment organic matter, and (iii) degree of binding at relatively weak sites on sediment phases that are exposed or modified by the action of proteins and other chemical constituents of the gut environment. 相似文献
2.
Murat
ztürk 《Marine Chemistry》1995,48(3-4)
Anoxic sulfidic waters provide important media for studying the effect of reducing conditions on the cycling of trace metals. In 1987–1988, dissolved and particulate trace metal (Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb) concentrations were determined in the water column of the anoxic Drammensfjord basins, southeastern Norway. The iminodiacetic acid type chelating resin (Chelex 100) was used for the preconcentration of trace metals. The trace metal concentrations were determined using atomic absorption spectrophotometry (AAS), differential pulse polarography (DPP), and differential pulse-anodic stripping voltammetry (DP-ASV).It was observed that the trace metals Mn and Fe were actively involved in the processes of redox cycling (oxidationreduction and precipitation-dissolution) at the O2/H2S interface. The dissolved concentrations of Mn, Fe and Co showed maxima just below the O2/H2S interface. The seasonal enhancement in the maxima of both dissolved and particulate Mn and Fe at the redox cline is mainly governed by the downward movement of water which carries oxygen. An association of Co with the Mn cycle was observed, while the total dissolved Ni was decreased by only 10–35% in the anoxic waters. The dissolved concentrations of Cu, Zn, Pb and, to a lesser extent, Cd decreased in the anoxic zone. 相似文献
3.
Metal concentrations of Cu, Fe, Mn, Ni, Pb and Zn in an infaunal facultative deposit-feeding bivalve, the Baltic clam Macoma balthica, in the Gulf of Gdansk (southern Baltic Sea) were assessed and compared to selected concentrations of metals in the environment. Between October 1996 and September 1997, dissolved and easy extractable (by 1M HCl) metal fractions of total suspended particulate matter (TPM) in the overlying water and of surficial sediments (<63 microm) were measured monthly at five sublittoral sites in the Gulf of Gdansk, and accumulated tissue metal concentrations in M. balthica were determined simultaneously. The study highlights the importance of sediment geochemistry as a factor modifying ambient trace metal bioavailabilities. Surficial sediments appeared to contribute most to the accumulation of Cu and Pb in M. balthica, reflecting the high metal availability in the Gulf. Assimilation of Cu from sediments is controlled by Mn components possibly through an inhibitory effect of Mn oxyhydroxides, while Pb accumulation from sediments depends on the organic content of the sediment. A dual metal uptake pathway, with a suspended particulate-bound fraction and surficial sediments, was apparent for Mn and Zn. Partitioning of Mn in sediments was related to the concentration of labile Fe, with increased levels of Fe tending to inhibit the accumulation of Mn by the clam. Tissue accumulated Zn might have been altered by the clam's internal regulation, making Zn tissue concentrations, to some degree, independent of its environmental level. The principal source of Ni accumulated by the clams exists in the soluble phase. 相似文献
4.
Impact of trace metals on denitrification in estuarine sediments of the Douro River estuary,Portugal 总被引：1，自引：0，他引：1
Denitrification influences the nitrogen budget in estuaries by removing fixed nitrogen from the inorganic pool; rates are dependent on both geological and geographic conditions as well as increasing anthropogenic impacts. In this study the effects of copper (Cu), chromium (Cr), zinc (Zn), cadmium (Cd) and lead (Pb), on the denitrification pathway were evaluated in subtidal and intertidal sediments of the Douro River estuary. Dinitrogen, N2O and NO2− production rates were measured in triplicate slurries of field samples under different treatments of metal concentrations. Results demonstrated that similar metal amendments led to different site responses for denitrification, suggesting that variations in sediment properties (metal concentrations, grain size, organic matter content, etc.) and/or differences in denitrifying community tolerance modulate the level of metal toxicity. Denitrifying communities in subtidal muddy sediments were not affected by increasing concentrations of metals. In contrast, intertidal sandy sites revealed high sensitivity to almost all trace metals tested; almost complete inhibition by Cr (95%) and Cu (85%) was observed for 98 and 79 μg per gram of wet sediment respectively, and by Zn (92%) at the highest concentration added (490 μg per gram of wet sediment). Moreover, the addition of trace metals stimulated N2O and NO2− accumulation in intertidal sandy (Zn, Cu, Cr and Cd) and muddy sediments (Cu and Zn), demonstrating a pronounced inhibitory effect on specific steps within the denitrification enzymatic system. In summary, the results obtained suggest that, according to the type of estuarine sediment, trace metals cannot only reduce total N removal from an estuary via denitrification but also can enhance the release of N2O, a powerful greenhouse gas. 相似文献
5.
Samples of anoxic intertidal sediments from the Mersey Estuary, north-west England, have been used in laboratory experiments to determine the rates and extents of metal (Cu, Zn, Fe, Mn) releases to solution under conditions of controlled resuspension and reoxidation. An experimental system for the study of sediment-water interactions at various temperatures, salinities, pHs and oxygen concentrations is described. The results indicate rapid initial losses of Fe and Mn from sediment but not Cu and Zn with longer term readsorption of Fe and Mn to give partitioning between the aqueous/ sediment phases for all four metals which is similar to that under the initial anoxic conditions. Cu and Zn show small, but measurable, net losses from the aqueous phase to the reoxidized sediment. Salinity variations exert little influence on the processes observed, but increasing temperature produces increased Cu, Zn and Mn in the dissolved fraction at equilibrium conditions. Exchanges of Cu and Zn between the sediment/water phases are rather insensitive to pH or oxygen concentration, but Fe and Mn do respond to increasing pH which suppresses their initial release on oxidation. Low oxygen concentrations can result in a slow but significant release of Fe. In relation to trace metal pollution in estuaries and biological availability, the results suggest that the resuspension and oxidation of polluted anoxic sediments is not an important process because of scavenging of soluble metals on to the resuspended material. 相似文献
6.
Rob F. Nolting Wim Helder Hein J. W. de Baar Loes J. A. Gerringa 《Journal of Sea Research》1999,42(4):2393
Dissolved and particulate trace metals (Cu, Cd, Pb, Zn, Ni, Fe and Mn) measured at six stations along the Scheldt estuary in October/November 1978 are compared with more recent data. Based on Ca content in the suspended matter, three distinct geochemical regions could be distinguished: the upper estuary (salinity 1–7) dominated by fluvial mud, mid-estuary (salinity 7–17) where the composition of the suspended matter remained relatively constant, and the lower estuary where marine mud prevailed. Re-suspension of sediments is the major factor controlling the composition of the particles in the upstream region. Anoxic conditions prevailed in the upper part of the estuary extending to a salinity of 15 in 1978, while at present the seaward boundary of the anoxic water body is located at less saline waters. Furthermore, the present-day metal load is much lower than in 1978. As a consequence of the changed situation, maxima in dissolved concentrations of redox-sensitive metals in the mid/lower estuary have moved as well, which affects the trace metal re-distribution pattern. In the anoxic zone, exchange processes between dissolved and particulate metal fractions were strongly redox regulated, with Fe and Mn as excellent examples. Iron was removed from the dissolved phase in the early stages of mixing resulting in an increase in the suspended particulate matter of the leachable ‘non-residual' Fe fraction from 2 to 3.5%. Due to its slower kinetics, removal of Mn from solution occurred in mid-estuary where oxygen concentrations increased. Cu, Cd and Zn on the contrary were mobilised from the suspended particles during estuarine mixing. External inputs of Pb, and to a lesser extent of Cu, in the lower estuary resulted in the increase of their particulate and the dissolved concentrations. Calculated Kd (distribution coefficient) values were used to assess the redistribution between the dissolved and particulate phase of the investigated metals. Due to the existence of the anoxic water body in the upper estuary, the importance of redox processes in determining the Kd values could be demonstrated. The sequence of Kd values in the upper estuary (Fe, Cd, Zn, Pb > Cu > Ni, Mn) is significantly different from that in the lower estuary (Fe > Mn > Pb, Ni, Zn, Cu, Cd). Thus, in such a dynamic estuary single metal-specific Kd values cannot be used to describe redistribution processes. 相似文献
7.
采用电感耦合等离子体质谱仪测定了厦金海域8种珊瑚中Cr、Mn、Co、Ni、Cu、Zn、As、Cd、Sn、Sb、Pb重金属的含量,通过数据处理、主成分分析方法,分析了重金属分布特征和其主要来源。采用单因子污染指数法对珊瑚重金属的污染水平进行了评价。结果表明,其平均浓度水平从大到小依次为:ZnMnSnCrCuAsNiPbSbCdCo。在8种珊瑚中,星柳珊瑚(Astrogrogia sp.)、等柳珊瑚(Paris fruticosa)、Paraplexaura sp.的重金属含量较高,花柳珊瑚(Anthogorgia sp.)和Guaiagorgia anas的含量较低。台湾海域珊瑚中Cu、Zn、Pb、Ni的含量、委内瑞拉海域珊瑚中Zn、Pb、Ni的含量远高于厦金海域珊瑚体内相同重金属含量,大堡礁珊瑚中Cu含量较厦金海域的略高。通过相关性分析发现,Cr、Co、Ni、Zn和Sn的种间差异较为显著。根据主成分分析,厦金海域珊瑚体内重金属元素可能的污染来源有:农业污染、港口生活污水和工业污水的排放、船舶油漆、涂料侵蚀、电镀工业。单因子污染指数法评价结果表明,6种重金属元素中,大佰屿、白哈礁和角屿的主要污染物是Mn。白哈礁、大佰屿站位的珊瑚体内重金属Mn处于重度污染水平,角屿站位的处于中度污染水平。 相似文献
8.
Metals (Cd, Cu, Ni, Zn, Mn and Fe) were analyzed seasonally over three years in sediments and in tissues of the clam Scrobicularia plana in four Moroccan Atlantic estuaries: Loukkos, Sebou, Bou Regreg and Oum er Rbia. Of these metals, Cd was at the lowest concentrations in sediment. Concentrations of Cu, Zn, and to a lesser extent Ni, in sediments suggest greater contamination in Sebou and Bou Regreg than in the other estuaries. The fluctuations of Mn and Fe concentrations in the fine surface sediments reflect their continental origin and show seasonal variations that indicate soil run-off following rain events. Concentrations of Cu, Zn, and especially Ni in clam tissues in these estuaries were generally higher than in some other common bioindicator bivalve species. The seasonal variations in S. plana's tissue metal concentrations are linked to patterns of reproductive activity for all metals except Cd and possibly Zn, whose tissue concentrations may be regulated. Mn and Fe concentrations in S. plana were positively correlated to sediment levels of these metals. 相似文献
9.
为全面了解我国黄渤海鳗草(Zostera marina L.)床重金属污染水平, 本研究以大连林阳北海、葫芦岛兴城、唐山乐亭-曹妃甸和青岛湾四处鳗草床为研究对象。于夏季采集鳗草、海水和沉积物样品并分析其重金属(Cu、Zn、Pb和Cd)含量。以此分析海草的重金属富集特征, 并对比评估不同鳗草床重金属潜在生态风险。结果表明, 夏季四处鳗草床海水重金属含量由高到低依次为: Zn > Cu > Pb > Cd, 均低于国家一级水质标准; 对沉积物来说, 重金属含量由高到低依次为: Zn > Pb > Cu > Cd, 均低于国家一级沉积物质量标准。鳗草对重金属的富集因重金属种类和海草积累部位而异, 其地上组织对Cu、Zn、Cd的富集能力高于地下组织。研究区域海水中Cu、Zn、Pb和Cd潜在风险等级均处于低风险水平。而对沉积物而言, 葫芦岛兴城鳗草床Cd的潜在风险等级处于较高风险水平(Ei值为156.9)。唐山乐亭-曹妃甸和青岛湾鳗草床的地质累积指数(Igeo)由大到小依次为: Cd > Pb > Zn > Cu。综合所有元素的潜在生态风险指数(IR), 葫芦岛兴城鳗草床的潜在生态风险值最高。 相似文献
10.
Buried nodules from siliceous sediments in the central Indian Basin are morphologically variable and mineralogically consist
ofd-MnO2 and incipient todorokite. Compositionally they are weakly diagenetic. The sediment coarse fractions (>63 μm) at different
depths show variable abundances of micronodules, volcanic glass shards and biodebris. Dissolution of biodebris increases and
abundance of micronodules decreases with increasing depth. Enrichment in Mn, Fe, Cu, Ni, Co, together with a decrease in organic
carbon in the sediment column, may result from diagenetic metal remobilization. Diagenetically remobilized trace metals might
have been utilized for the growth of micronodules over the buried nodules.
The details of the chemical analyses of buried nodules and associated sediments can be obtained from the first author. 相似文献
11.
E.P. Nobi E. DilipanT. Thangaradjou K. SivakumarL. Kannan 《Estuarine, Coastal and Shelf Science》2010
Spatial distribution of metal concentrations in the surface sediment samples collected from 16 marine locations covering different coastal ecosystems such as mangroves, seagrasses, dead coral and sandy beaches of the Andaman islands, India was studied. pH, EC, sediment grain size and heavy metal (Al, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn) concentrations were determined and contamination factor (CF) and geo-accumulation index (Igeo) were calculated to understand the pollution status of the study area based on the background values. CF of different heavy metals has revealed that different metals have different levels of accumulation viz. Al: 0.01–0.22, Mg: 0.38–1.85, Fe: 0.06–0.74, Mn: 0.04–1.18, Cu: 0.18–2.93, Cr: 0.52–12.6, Zn: 0.3–1.39, Ni: 0.06–0.89, Pb: BDL–0.74, Co: 0.1–0.35 and Cd: 2.3–12.9. In general the metal concentration was less in these ecosystems when compared to similar ecosystems of mainland of India. Concentration of some metals like Cr and Cd was comparatively higher than the background values which is an important issue of concern to the coastal managers of the region. Spatial data on heavy metals, collected now, would help the coastal zone managers to identify the vulnerable sites and take remedial actions. 相似文献
12.
Concentrations of Cd, Cu, Cr, Co, Ni, Zn, Fe, Mn, Pb, As, and Sb were determined in sediment trap and bottom sediment samples collected seasonally from a station on the eastern Turkish coast of the Black Sea. Cd, Pb and Mn concentrations were highest in the sediment trap samples except during the summer period, whereas Co, Ni, Zn and Fe levels were much lower than corresponding levels found in the surface sediments. Cu, Cr, As and Sb levels showed no definite trend with sediment type. In general, with the exception of Cr, relatively lower metal concentrations in the sediment trap material were determined in the summer period. The highest mass flux, 56.5 g m−2 day−1, was measured during autumn. The highest flux of heavy metals also occurred during autumn and was strongly dependent on particle mass flux. Based on these results, we suggest that the downward vertical transport of particulate heavy metals in this region is related to the high degree of land erosion and the resultant particulate flux dynamics, which occur here. It was noteworthy that the highest concentrations of Cd, Cu, Co, Zn, Fe and Sb in particles were measured during winter a finding which suggests that enhanced fossil fuel combustion, which occurs during this period in adjacent urban and industrial areas plays an important role in the metal composition of sinking particles in nearshore waters. 相似文献
13.
应用半静态双箱动力学模型室内模拟了沉积物暴露条件下文蛤Meretrix meretrix 对Cu、Pb的生物富集,通过对富集与排出过程中文蛤体内重金属污染物的动态监测和对富集与排出过程监测结果的非线性拟合,得到了文蛤富集重金属的吸收速率常数K1、排出速率常数K2、生物富集因子BCF(bioconcentration factors)、生物学半衰期B1/2等动力学参数。拟合结果得到的Cu、Pb各动力学参数分别为,K1为4.633372.3754;K2为0.05120.0798;BCF为60.76461414.9634;B1/2为8.6913.55。对模型的拟合优度检验结果显示,沉积物暴露条件下文蛤对重金属Cu、Pb的生物富集数据符合双箱模型,模型的拟合优度良好。比较结果得出,吸收速率常数K1及生物富集因子BCF均随着外部水体金属暴露浓度的增大而减小;文蛤对Cu富集能力大于Pb;Cu在文蛤体内的生物学半衰期B1/2大于Pb;理论平衡状态下生物体内Cu、Pb的含量CAmax随着外部水体中金属暴露浓度的增大而增大,且呈显著正相关,实验结果表明沉积物暴露条件下双箱动力学模型在一定条件下是可以应用于文蛤的富集动力学研究的,仍需要进一步开展不同条件下实验研究分析。 相似文献
14.
用原子吸收光谱法(AAS)和原子荧光光度法(AFS)测定了采集于北海银滩镇、厦门海门岛、宁德漳湾镇、乐清西门岛、温岭坞根镇、三门花桥镇等地区自然滩涂以及温岭坞根镇养殖区的可口革囊星虫(Phascolosoma esculentas)及其栖息地的底泥样品中Zn、Cu、Mn、Fe、Cd、Pb、Hg 和As 等8 种重金属含量, 并对检测结果进行了含量特征、生物体与栖息地底泥中重金属含量相关性分析、生物体重金属富集系数分析。结果表明: 不同栖息地可口革囊星虫间的重金属含量差异性显著(P<0.05), 各群体中Pb 含量均超过标准, 厦门海门岛群体中Cd 含量超标; 厦门海门岛、乐清西门岛自然滩涂栖息地和温岭坞根镇养殖区等底泥中重金属含量相对较高, 所有采样点底泥中Cu 含量以及乐清西门岛自然滩涂底泥中Cd 含量达到沉积物质量标准Ⅱ类; 可口革囊星虫对Zn、Cu、Fe 的富集系数均小于1, 对Mn、Cd、Pb、Hg 和As 的富集系数均大于1。Zn、Cu、Fe、Pb 和As 的富集系数在大部分群体间差异性较小; 可口革囊星虫中的Fe 和As 含量与底泥中的Fe 和As 含量高度正相关, Zn 和Hg 含量的相关性次之, 其余重金属元素含量的相关性较差。 相似文献
15.
Joanne M. Deely J. Clair Tunnicliff C. Jane Orange Wayne H. L. Edgerley 《新西兰海洋与淡水研究杂志》2013,47(3-4):417-427
Abstract Surface sediment samples (60 μm‐2 mm, and < 60 μm fractions) from the Waiwhetu Stream, Lower Hutt City, New Zealand, were leached with dilute HCl to remove the mobile heavy‐metal fraction. Cd, Cr, Cu, Pb, Zn, Al, Fe, and Mn analyses of the leachates show that sediments of the upper reaches area of the stream are generally uncontaminated. In contrast, sediments in the lower reaches area are highly contaminated, despite clean‐up measures in the late 1970s. Lead and Zn are the most significantly enriched metals with concentrations over 1000 mg kg?1 adjacent to some drains. In the polluted zone, metals originate from either upward remobilisation from underlying sediment (contaminated in the early 1960s and 70s) or more recent industrial spillages. Similar trends exhibited by Cd, Cu, Cr, Zn, Pb, and Al indicate that a proportion of the metal enrichment downstream probably results from a naturally higher clay content of sediments near the mouth of the stream. Fe and Mn show reverse trends to the other metals, indicating that a high proportion of these two metals occurs in substrate different to that of the other metals. The orange brick‐coloured sediments of the upper reaches of the stream indicate oxides upstream; the black sediments in the lower reaches indicate sulphides downstream. 相似文献
16.
泥螺(Bullacta exarata)作为黄河三角洲区域成功引入的滩涂养殖种类, 为当地获得了巨大的经济效益, 但对其生态影响还了解不多。为了解该区域泥螺体内重金属含量并评价其生物质量, 于2012年8月对该区域进行泥螺和沉积物样品采集调查和分析。采用富集系数K、残留量指数I以及金属污染指数IMP进行分析。结果表明, 黄河三角洲沉积物及泥螺体内6种重金属含量均相对较低, 多数符合国家海洋沉积物质量标准第一类。泥螺对不同重金属的富集系数K有明显差别, 其中对Cu 和Cd 的富集能力最强。残留量指数I富集系数K及金属污染指数IMP均表明, 黄河三角洲潮间带泥螺对重金属的富集程度均较低, 说明该海域泥螺未受到重金属离子的污染。根据国家生物质量标准分析, 黄河三角洲潮间带泥螺的生物质量总体较好, 生物体内重金属含量总体上与海水中重金属含量无显著的相关性。 相似文献
17.
The sediment–water partitioning of radiolabelled Cd, Hg and Zn has been investigated along an estuarine salinity gradient using samples from the Mersey Estuary, UK. Partitioning was studied using untreated particles, and particles that had been extracted using either a reducing agent (NH2OH.HCl–HOAc) or an oxidising agent (H2O2) in order to qualitatively evaluate the relative roles of Fe–Mn oxides and particulate organic matter (POM), respectively, on metal uptake. The extent of Cd partitioning between sediment and water, parameterised in terms of the distribution coefficient, KD, exhibited a reduction with increasing salinity, regardless of whether or not particles had been digested. However, the magnitude of KD decreased significantly following either chemical treatment, suggesting that both oxides and organic matter are important sorbents for Cd. The KD for Hg in the presence of untreated particles increased with increasing salinity, and chemical reduction of the particles enhanced the uptake of Hg and reinforced this trend. Particle oxidation led to a significant reduction in the KD for Hg, and uptake by the particles decreased with increasing salinity. These observations suggest that POM is considerably more important than Fe–Mn oxides in the removal of aqueous Hg, and that its presence is a prerequisite for enhanced sorption (or salting out) at elevated salinities. The salinity dependence of KD for Zn displayed characteristics of both Cd (below salinities of about 5) and Hg (at greater salinities). However, the magnitude of KD for Zn uptake was relatively insensitive to either chemical treatment, suggesting that oxides, POM, and residual phases contribute to the overall sorption of Zn by estuarine particles. Regression analyses of the metal partition data suggest that sorption to oxides and POM is nonadditive, and that the salinity dependence of metal partitioning results mainly from salinity-controlled interactions between metal and organic matter. Sequential extraction of metals bound to untreated and chemically treated particles in the partitioning experiments indicated that the exchangeability or lability of all metals increased on removal of either oxides or POM. This implies that sorption sites of relatively high energy are destroyed (or become less accessible), or sorption sites of relatively low energy are created (or become more accessible) on chemical treatment. These observations support a conceptual model for the particle surface whose integrity and binding properties are only maintained by the coexistence of and interaction between oxides and organic matter. 相似文献
18.
Mangrove wetlands can reduce heavy metal pollution by trapping heavy metals. In this study, the concentration,transport and bioaccumulation of Cr, Cd, Cu, Zn and Pb in the sediments and different parts of Aegiceras corniculatum at four different sites in the Qinzhou Bay in southwestern China were investigated. The results showed that although the potential ecological risk of all five heavy metals was slight, the concentration of Cr was at a moderate pollution level due to the emissions of industries and aquaculture waste water. Core sediment records indicated that the concentrations of heavy metals at the depth of 0–20 cm were relatively high, showing an increasing trend of heavy metals over the past 20–30 years. Cr, Cu, Pb and Cd accumulated mainly in the roots of A. corniculatum, while Zn accumulated mainly in the stems. Aegiceras corniculatum showed the strongest transport capacity for Zn and Cu and the strongest bioaccumulation ability for Cd. Compared with other mangrove communities, A. corniculatum can be chosen as a restoration species in tropical and subtropical coastal zones polluted by Zn, Cu and Cd. 相似文献
19.
孔隙水是沉积物-海水界面链接沉积物颗粒和上覆水体的一个重要过渡相态,针对其研究可更好地了解痕量金属在固-液界面的早期成岩过程。近年来,针对孔隙水中痕量元素研究的方法较为匮乏,为此建立了一种分析测定海洋沉积物孔隙水中7种痕量金属元素(Mn、Cu、Zn、Ni、Cd、Co、Pb)的方法,该方法使用Nobias PA1树脂进行富集分离,再使用电感耦合等离子体质谱(ICP-MS)进行测试,可针对孔隙水中的痕量金属元素进行准确分析。通过实验结果发现该方法最优实验条件为: Nobias PA1树脂富集时的pH值为5.5~6.0,洗脱酸浓度为1.3 mol/L硝酸,体积为1 mL。同时,样品需进行紫外消解4 h以上以分解有机络合物,该消解步骤对Cu和Co这两种元素尤其重要。该方法通过加标回收获得Mn、Cu、Ni、Co和Pb的回收率在92%~100%, Zn和Cd的回收率分别为72%和82%; Mn、Cu、Zn、Ni的方法检出限范围为0.03~0.53 nmol/L, Cd、Co、Pb的方法检出限范围为2.66×10-3~8.60×10-3 nmol/L,满足孔隙水中痕量金属浓度的测试需求。同时,根据检出限计算的结果显示,孔隙水样品只需1 mL,即可应用该方法进行测试。应用该方法测试了一根采集于北黄海中部沉积物短柱的孔隙水样品,测试结果显示其垂相分布合理、较符合早期成岩过程规律。此研究为分析海洋沉积物孔隙水中痕量金属元素提供了一种准确而简便的方法。 相似文献
20.
用Zeeman－5000型原子吸收分光光度计火焰法测定了上海滨岸潮滩沉积物中Cu、Pb、Fe、Mn、Zn、Cr的总量及其5种地球化学形态含量，发现根际沉积物中的重金属含量一般低于表层沉积物，但在重金属含量水平上，均为Fe＞＞Mn＞Zn＞Cu，Pb，Cr；单因子方差分析表明重金属在根限沉积物中存在显著的季节变化（p＜0.05＝，Cu、Pb、Fe、Mn、Zn、Cr在高潮滩芦苇根限沉积物中的含量均在夏、秋季出现最低值或次低值，在中潮滩海三棱Biao草根际沉积物中的季节含量随采样地点不同而变化，但与同一地点表层沉积物中的含量相关性很好，除Cr（r＝0．18）外，相关系数（r）分别达到0．77、0．74、0．65、0．84、0．77；Cu、Fe、Zn、Cr在沉积物中均以残渣态含量为主，Pb、Mn的碳酸盐结合态含量较高，秋季各重金属元素的碳酸盐结合态与铁锰氧化物结合态之间发生形态上的迁移与转化。 相似文献