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1.
The adsorption of Pb, Cu and Cd on synthetic hydrous ferric oxide (HFO) has been performed under simulated environmental conditions of the Changjiang Estuary. An improved M2 - H exchange-adsorption model is proposed to explain the adsorption processes. The adsorption of these elements falls in the order: Pb ≥ Cu > Cd and has a good coincidence with the field results obtaimed from the Estuary. It has been concluded that the adsorption processes of Pb and Cu on HFO are mainly chemical actions, whereas static-electrical action dominates in the case of Cd. 相似文献
2.
The thermodynamic process of two macroalgae, Sargassum fusiforme and Lamin aria japonica, absorbing heavy, metal ions Cu^2 , Pb^2 , Cd^2 and Ni^2 . has been studied. The result indicates that the absorption isotherms of these two macroalgae clearly accord with the Landmuir adsorption model. The absorptive processes of S. fusiforme and L. japonica for Cu^2 are endothermal, and at 35℃, the adsorption heat of these two algae is 59.5kJ/mol and 76.8 kJ/mol respectively. Temperature could affect the algae‘s adsorption capacity. Their adsorption capacity increases with temperature (25℃ and 35℃). 相似文献
3.
This paper explores the accumulations ana distributions of Cd, Pb and Cu in clam Area granosa through determining their contents in Dlood and soft parts. The results show an order of concentration factors for these metals therein as: Cd>Cu>Pb; the values of concentration factors and the patterns of distribution are similar for Cu and Pb but different from Cd. Concentration factors in blood can reflect the enrichement abilities of soft parts. Exposure experiments have indicated that the Pb level in blood is controlled by Pb concentrations in surrouding seawater, changing with time, that the Pb cocentration causing poisoning in the seawater is 1-100 μg/l, and that the Pb content in blood and soft parts of Area granosa increases with that of Pb increasing in seawater. There exist relationships of double logatithmic concentrations for Pb among the three mediums. 相似文献
4.
对虾工厂化育苗在我国沿海已经普及,对虾人工养殖也在沿海地区蓬勃发展,到1992年养殖面积已达200多万亩,人工育苗场全国约有上千个。养殖对虾已成为我国水产业中规模最大、经济效益最高的水产品。但近几年来沿海地区的工业飞速发展,沿岸海水均受到了不同程度的污染,各对虾育苗场卵孵化率普遍下降。今年我国养殖对虾又出现了大面积暴发性死亡,原因是复杂的,但作者认为,治虾病之本应是治水质。众所周知,一切生物的幼体阶段都是最敏感的时期,海水中的金属离子对对虾幼体生长的影响已有报道(吴彰宽等,1988; Lawrence et al.,1981),但其实验环境、方法及条件各有不同。作者于1992年5月至1993年4月在海阳育苗场作了现场实验,本文根据实验结果分析和研究了Zn、Cd、Pb、Cu金属离子对中国对虾受精卵及无节幼体生物毒性的影响;不同pH值海水加入不同浓度的混合金属离子,对无节幼体生长的毒性影响;不同盐度的海水加入不同浓度的混合金属离子对无节幼体生长毒性的影响。 相似文献
5.
6.
《Marine Chemistry》2001,74(1):65-85
Here it is demonstrated that both Porphyra spp. and Enteromorpha spp. of macro-algae display similar and very marked seasonal variations in their concentration factor (CF) of Cu, Pb, Cd and Hg in field conditions. The CF variations are specific for each metal and reproducible over several years. The way variations in the biological activity affect the equilibrium and kinetics of the interaction between trace metals and live algae was studied in vitro. Natural seawater was used as the culture medium. Voltammetry was used for the determination of natural organic ligands and trace metals except Hg, which was determined by mercury cold vapour after on-line pre-concentration. Titrations with the relevant metal demonstrated that the maximum binding capacity of the algae was not significantly dependent on the season for Pb (ca. 100 μmol gdry algae−1), Cd (ca. 50 μmol g−1) and Hg (80–100 μmol g−1). Marked seasonal variations were observed for Cu (ca. 40 μmol g−1 in January; 70 μmol g−1 in May; and 100 μmol g−1 in August). The conditional stability constants of metal–algae complexation sites were seasonally independent and similar for both algae: logKMS′=8.5±0.3 (Cu), 5.6±0.2 (Pb), 5.3±0.2 (Cd) and 18.0±0.3 (Hg). Exudates with a strong Cu complexing capacity (logK′CuL=12.47±0.06) were determined in cultures with added Cu, Pb or Cd concentrations, and identified by cathodic stripping voltammetry (CSV) as cysteine or glutathione. All the tested metals promoted the liberation of exudates, both cysteine- and glutathione-like ligands were exuded in the presence of Cu, only cysteine-like ligands in the presence of Pb, and only glutathione-like ligands in the presence of Cd, the rise depending of the season of the year, particularly for Cu. Highest levels were produced in the presence of added Pb. When exposed to either 1- or 100-μM total dissolved metal concentrations, the metal uptake, and its rate, varied with the season and the algae. 相似文献
7.
于1990年10月 - 1992年7月在室内条件下测定黄河中游乌拉特前旗、包头黄河大桥及清水河地段水体中天然配体与铜、铅、锌、镉反应的络会容量（C?C），计算总条件稳定常数（K）和络合容量指数（I）。实验证明：乌拉特前旗水体中络合客量最大，包头和清水河相近。络合容量顺序为：Cu＞Zn＞Cd＞Pb，和可溶性有机碳及碳酸盐分析结果一致。总条件稳定常数为：KPbL最大，KCuL，KZnL，KCdL相近。和长江水做了比较。络合容量指数在IgK相近情况下，随络合容量增大而增大。 相似文献
8.
The process of adsorption of metal ions by immobilized marine algae with the existence of clay was investigated. It can be noted from the results that, after mixing with clay, the adsorption rate increases rapidly with the increasing amount of the marine algae. When pH=5, the best ratio between the clay and the marine algae is 1：4 for Pb^2＋. The result of in situ handling of the waste water containing heavy metals shows that the average adsorption rates of heavy metal irons Cu^2＋, Cd^2＋, Pb^2＋ and Ni^2＋ are all over 70 %. 相似文献
9.
海湾扇贝体内重金属含量研究 总被引：3，自引：0，他引：3
采用用微波消解对海湾扇贝样品进行处理,用原子吸收光谱仪测定海湾扇贝合组织中重金属Pd、Cu、Cd、Zn的含量,对重金属含量进行评价,并对海湾扇贝养殖水体进行同步监测。结果表明:Pb、Cu、Cd、Zn在海湾扇贝各组织中的含量不同,Pb、Cu、Cd在内脏中含量最高,Zn在扇贝柱中含量最高,与标准值相比,Pb、Cu在各组织中的含量均符合标准,而Cd在除体液外各组织部位中的含量均超过《无公害食品水产品中有毒有害物质限量》规定的1.0mg/kg标准值,而海湾扇贝养殖水体及沉积物中重金属含量均符合一类海水水质标准。 相似文献
10.
The relative contributions of adsorption to particulate surfaces, complexation with surface-active organic ligands and uptake by micro-organisms were evaluated with respect to their importance in the surface microlayer enrichment (‘partitioning’) of Cd, Pb and Cu. The contributions of each process were inferred from field data in which partitioning of the dissolved and particulate forms of Cd, Pb and Cu, total and dissolved organic carbon, particles and total bacteria were observed. In the South San Francisco Bay estuary, particle enrichment appears to control trace metal partitioning. Trace metal association with the particulate phase and the levels of partitioning observed were in the order Pb > Cu > Cd and reflect the calculated equilibrium chemical speciation of these metals in computer-simulated seawater matrices. 相似文献
11.
Changyou Wang Xiulin Wang Bodong Wang Chuansong Zhang Xiaoyong Shi Chenjian Zhu 《Oceanology》2009,49(1):64-72
Dissolved concentrations of Cu, Pb, Zn, and Cd were measured in the Changjiang estuary and its adjacent waters. The results
indicate that the ranges of dissolved heavy metals in the studied waters are as follows: Cu = 1.0−6.9 μg/L, Pb = 0.10−0.39
μg/L, Zn = 3.2−9.1 μg/L, and Cd = 0.011−0.049 μg/L. The behavior of the dissolved Cu was essentially conservative, but a high
scatter was observed for the high salinity samples, and it is the same with Zn and Pb. The overall concentrations of dissolved
Cd increase with the salinity. There were no differences between the surface, middle, and bottom layer for Cu, Pb, Zn, and
Cd. Seasonal changes of their averages were not obvious on the whole. River discharges, sedimentary dynamics, and biological
processes might determine the profiles of heavy metals.
The text was submitted by the authors in English. 相似文献
12.
《Marine Chemistry》1991,32(2-4)
The adsorption of trace metals (Pb, Zn, Cu, Cd and Hg) on calcite, kaolinite and bentonite has been studied in Krka river water of various salinities (S = 3, 20 and 38‰).Model experiments were performed at pH 8 in natural water and in UV-irradiated water samples to determine the importance of natural soluble organic matter. Cold vapour atomic absorption spectrometry was used for the Hg determination, and a differential pulse anodic stripping voltammetry (DPASV) method for determination of other trace metals, using either a hanging mercury drop electrode or a mercury-coated glassy carbon working electrode. The following results have been obtained on calcite:
- 1. (1) a powerful absorption of Pb and Zn was observed for both natural and UV-irradiated waters at S=20‰;
- 2. (2) a strong adsorption of Hg was observed in natural water, and significantly lower adsorption in UV-irradiated water at all three salinities, particularly at low salinity;
- 3. (3) Cd adsorption was of medium intensity in both waters at S=20‰;
- 4. (4) Cu was practically not adsorbable in both waters at S=20‰ if the total Cu ion concentration was lower than the copper complexing capacity value;
- 5. (5) Cu adsorption was of a medium intensity at S=38‰. It has not influenced by the EDTA model ligand.
13.
海水养殖池沉积物中重金属形态和生物酶活性的关系研究 总被引：1，自引：0，他引：1
以连云港市对虾养殖池表层沉积物为研究对象,采用Tessier连续萃取法,研究了表层沉积物中重金属(Cu、Zn、Pb、Cd、Cr、As、Mn)的赋存形态和酶(脲酶、碱性磷酸酶、过氧化氢酶、转化酶)活性的相关性。结果表明,重金属Cu和Zn以有机-硫化物结合态为主要的赋存形态,Pb以铁锰氧化物态为主要的赋存形态,Cd以可交换态(平均33.47%)和碳酸盐结合态(平均31.16%)为主要存在形态,Cr和As主要以残渣态存在,Mn的铁锰氧化物态比例最高。脲酶的活性范围为0.45—8.96mg/(g·24h),碱性磷酸酶活性范围为2.45—6.69mg/(g·24h),过氧化氢酶活性范围为0.14—2.36m L/(g·min),转化酶活性范围为0.45—10.45mg/(g·24h)。脲酶活性与Cd、As的可交换态、Cd的碳酸盐结合态、Cu、As的铁锰氧化物态、Zn、Pb、Cd、Mn的有机硫化物态之间显著相关;碱性磷酸酶活性与Zn、Cd的铁锰氧化物态显著相关;过氧化氢酶活性与Cd的可交换态、碳酸盐结合态及残渣态、Cu、Cd、As的铁锰氧化物态、Zn、Pb、Cd、Mn的有机硫结合态之间显著相关;转化酶活性与Cu、Cd、As的可交换态、Cd的碳酸盐结合态、Cu、Cd、As的铁锰氧化物态、Zn、Pb、Cd、Mn的有机硫化物态、Cd、As的残渣态之间显著相关。酶活性可以用来指示海水养殖池沉积物中重金属的形态转化过程。 相似文献
14.
Concentrations of P and of heavy metals (Zn, Cd, Pb, Cu) were determined in sediment cores from the Peel-Harvey Estuary in Western Australia. Two cores were extracted, each representing one of the two basins of the estuary. Sediments were dated by surplus210Pb, by137Cs and by changes in the Fe/S ratio. Increasing exports of P from the mainly agricultural catchments have resulted in more than a doubling of both total P and acid extractable inorganic P in sediments of the estuary. Accumulation of P in the estuary is less than expected for complete retention of inputs of P from the major tributaries. Historical data show that since 1950 average concentrations of dissolved inorganic P have approximately doubled in the Peel Inlet and increased by times seven in the Harvey Estuary. Increases in concentrations in surface sediments of acid extractable Zn, Cd, Pb and Cu are noticeable in the Peel Inlet, and of Zn and Cd in the Harvey Estuary. The greatest increase, relative to background, is shown by Zn. Concentrations of extractable Zn and Cd in surface sediments are similar to those estimated from average concentrations in the water column for equilibrium adsorption to organic matter in sediments. Extractable Pb is greater than estimated for equilibrium adsorption to sediments. Extractable Cu is of the order of what can be expected for equilibrium adsorption to sediments in the Peel Inlet, but is less than expected in the Harvey Estuary. 相似文献
15.
16.
Mudflats play a vital role in maintaining the dynamic balance between sea and land. To understand the characteristics, sources, and pollution risks of six heavy metals(As, Cd, Cr, Cu, Hg, and Pb) in the coastal mudflats on the Leizhou Peninsula, 257 surface sediment samples were studied using mathematical statistics, correlation analysis, and factor analysis. The results show that the overall concentrations of these heavy metals are low although there are several high abnormal points in the loca... 相似文献
17.
深圳湾福田潮滩重金属含量及对大型底栖动物的影响 总被引：9，自引：0，他引：9
根据2002年1月和10月在深圳湾福田潮滩同时获得的大型底栖动物和重金属数据进行分析表明，深圳湾福田潮滩Cu、Pb、Zn、Cd含量明显超标．2002年10月Pb、Cd、Cu、Zn含量的平均值比2002年1月高．与历史资料对比，近几年Cu含量有增加趋势．2002年1月，深圳湾福田潮滩奇异稚齿虫密度与沉积物中Pb、Cd、Cu、Zn含量均有显著负相关关系．尖刺缨虫密度与Pb、Cd、Zn含量均有显著负相关关系，与Cu的相关系数也接近显著相关临界值．2002年10月，只有小头虫密度与Cd有显著正相关关系．文中分析了影响重金属与大型底栖动物数量关系的环境因素． 相似文献
18.
Environmental status of Daya Bay surface sediments inferred from a sequential extraction technique 总被引：1，自引：0，他引：1
Xuelu Gao Chen-Tung Arthur Chen Gang Wang Qinzhao Xue Cheng Tang Shaoyong Chen 《Estuarine, Coastal and Shelf Science》2010,86(3):369-378
The chemical partitioning of 12 trace metals (Ba, Cd, Co, Cu, Mn, Mo, Ni, Pb, Sc, Sr, U, Zn) in 9 surface sediments from Daya Bay, northern South China Sea, was studied by a four-step sequential extraction technique to assess their environmental/pollution status. The studied metals take on different fraction composition patterns, and some of them show significant spatial variation especially for Cd. A majority of the studied metals can be considered immobile because of their high percentages in the residual fraction. It seems that the Daya Bay surface sediments have not yet been polluted by the studied heavy metals which are used as parameters to classify marine sediment quality, i.e., Cd, Cu, Ni, Pb and Zn. For all metals except for Pb, the extent of anthropogenic influences on their total concentrations in the Daya Bay surface sediments is generally imperceptible. The metals’ potential risks to the environment were assessed, and the results showed that they have generally no risk or low risk except for Cd, Mn and Sr. 相似文献
19.
城市道路沉积物重金属风险评价是表征城市环境质量的有效途径。采用重金属化学形态和生物可利用性来评估其生态风险更合理,越来越受到人们的关注。本文采集山东省青岛市崂山区10条次干道沉积物样品,分析不同粒径沉积物中Zn、Cd、Cu、Pb的含量、化学形态和生物可利用性,采用地累积指数(Igeo)和改进的生态风险指数(RIm)评价细粒径(小于75μm)沉积物中重金属污染水平和生态风险。结果表明:(1)沉积物粒径越小,重金属含量则越多。当粒径小于75μm时,Zn、Cd、Cu和Pb平均含量分别为山东省土壤元素背景值的10.63、6.07、3.39、2.70倍。(2)随粒径的减小,生物可利用性增大。小于75μm粒径的Zn、Cd、Cu和Pb的生物可利用态百分比为74%、78%、66%和55%。(3)评价结果显示,Zn、Cd、Cu和Pb的值分别为2.83、2.01、2.22和2.05,结果均为偏重度污染。(4)评价结果为较高生态风险,其中Cd属于极高风险,Cu和Pb属于中等风险,Zn属于低风险,Cd对的贡献高达75%。以重金属污染水平、迁移率、生物可利用性和生态风险为评价依据,认为Zn、Cd、Cu、Pb的风险均较大。该研究可为青岛市道路重金属污染防控提供指导。 相似文献
20.
以黄河口海域表层沉积物为研究对象,研究沉积物对重金属Cu、Pb的吸附特性,将沉积物筛分为4种粒级,探讨粒度、pH值、吸附时间和吸附剂初始浓度对重金属吸附的影响。结果表明:沉积物粒径越小,对重金属的吸附量越大;吸附平衡时间有所差异,但在1.5h均能达到吸附平衡;吸附量均随pH值升高而逐渐增加,但铜的吸附较铅的吸附速度快;铜的吸附量与吸附剂初始浓度呈线性关系,而铅的吸附量在初始浓度较低时变化明显,随初始浓度增加吸附量增加减小;沉积物对铜吸附等温线符合Langmuir型,铅吸附等温线符合Freundlich型,吸附类型存在差异。重金属在沉积物中的吸附规律研究为黄河口海域污染调查及治理提供了科学依据。 相似文献