SOLID-LIQUID INTERFACE PROCESS OF HEAVY METALS IN THE CHANGJIANG ESTUARYKINETICS OF ADSORPTION OF Pb, Cu AND Cd ON HFO

The adsorption kinetics of Pb, Cu and Cd on hydrous ferrk oxide (HFO) has been approached in tthe simulated environmental conditions of the Changjiang Estuary. The forward adsorption rate constants of different systems under different temperatures have been determined, and the activation energies of the adsorption for Pb and Cu evaluated (Pb=7 kcal/mol, Cu= 11 kcal/mol). The results show that Pb and Cu are strongly adsorbed by HFO; the order of their adsorption rate is found to be Pb≥Cu≥Cd, which follows thte order of their theonody-namic equilibrium constants. It has been demonstrated that the surface exchange-adsorption is the determining step of the solid-liquid interface process. The field investigation results are theoretically explained by the kinetic mechanism.     

THE BEHAVIOR AND SEDIMENTATION MECHANISM OF Pb, Cu AND Cd IN SEDWAENTARY PHASE OF THE CHANGJIANG ESTUARY

The authors have determined the distributions of Ph, Cu and Cd ia surface sediment, acid-soluble fraction and interstitial water of the Changjiang Estuary and analysed the relationship between them and some environmental parameters, finding that there exists a quasi-equilibrium between the interstitial water and the sediment. The distribution of Pb or Cu in both phases it controlled mainly by the adsorptioa-desorption and deposition-solution processes of HFO" and org." in the sediments, whereas Cd is mainly controlled by the depoahisn-Jolution process of CdS. The sedimentation mechanism of Ph, Cu and Cd in the Changjlang Estuary is preliminarily proposed.     

RESEARCH ON THE DETERMINATION OF Pb, Cd, Cu AND Zn IN SEAWATER BY STRIPPING VOLTAMMETRY

In this paper, a comparison viral made between the two results of determining Pb, Cd, Cu and Zn in seawater by direct current (tripping voltammetry (DCS) with rotating glass carbon electrode and by differential pulse stripping voltammetry (DPS) with hanging mercury drop electrode (HMDE). By DCS, the range of linear calibration curves obtained was 4×10-3 M-2×10-7M for Cu, Zn and Cd, and 4× 10-9M-2×10-3M for Pb. By using DPS, the range of linear calibration curve was as follows: Cu 0.65-1.9 ppb; Pb 1.0-10 ppb; Zn 0.65-2.0 ppb; Cd 0.02-0.14 ppb. It was found that DCS could be used for determining Pb, Cu, Zn in coastal waters, but it is necessary to add gallium ion to it to eliminate the interference of Cu-Zn inter-metallic compound for determining Zn. The DPS is better for determinig Cd.     

重金属Cu、Pb对泥鳅(Misgurnus anguillicaudatus)卵细胞凋亡及DNA损伤的SCGE试验

采用室内暴露试验方法,以单细胞凝胶电泳技术(SCGE)检测,研究了Cu、Pb不同浓度梯度与不同暴露时间联合染毒对泥鳅卵细胞DNA的损伤.结果表明,各Cu、Pb浓度组DNA平均迁移长度增加,与阴性对照组比较差异有显著性(P＜0.05).此外,随着Cu、Pb染毒剂量的增加,各试验组DNA的平均迁移长度逐渐增加,在试验浓度梯度范围内(Cu 0.01mg/L+Pb 0.05mg/L、Cu 0.10mg/L+Pb 0.50mg/L、Cu 0.25mg/L+Pb 0.75mg/L),存在较为显著的剂量-效应关系(P＜0.05),但未见明显的时间-效应关系(P＞0.05).Cu、Pb可引起泥鳅卵细胞凋亡和DNA损伤,卵细胞的不同损伤水平可望作为较为理想的水环境基因毒性指标.     

FORM DISTRIBUTION OF Zn, Cd, Pb AND Cu IN WATERS OF THE NORTHWEST BOHAI GULF

The forms distribution of Zn, Cd, Pb and Cu in waters of the Northwest Bohai Gulf is investigated by inverse polarography of anti-adsorption physically coated mercury film electrode, the higher content of most forms of trace metals is in polluted estuary water, and unstable Zn and Pb are in anomalous distribution. The average concentrations read ΣZn 20.0μg/1 (14.5-36.6 μg/l, ΣCd 0.11pg/1 (0.080-0.14μg/1), ΣPb 1.0μg/1 (0.58-1.6 μg/1), and ΣCu 5.2μg/1) (2.37-8.43 μ/1) respectively.     

DIRECT AND SIMULTANEOUS DETERMINATION OF Zn, Cd, Pb, Cu and Bi IN SEAWATER BY DERIVATIVE-VOLTAMMETRY

This paper suggests direct and simultaneous determinations of the reducible species of Zn, Cd, Pb, Cu and Bi in seawater made by the derivative-differential pulse anodic stripping voltammetry with a hung mercury drop electrode. The influence of Cu on the determination of Zn in this experiment condition has been studied, of which both the accuracy and precision are satisfactory. The procedure of determination is so quick, simple and convenient that the background concentration of these five elements in coastal seawaters can be determined only by adjusting the acidity of seawater to pH 2.5 and by taking 10-minutes plating time. Actual measurement time of these five elements for every sample is approximately 25 min.     

Zn, Pb, Cu AND Cd IN PHASES OF SEDIMENTS IN ZHUJIANG ESTUARY

In this paper, the samples of sediments collected from five sampling-stations in the river-sea water mixing zone of the Zhujiang Estuary have been determined by the sequencial extraction procedure, anodic stripping voltammetry and atomic emission spectrometry etc. The contents of the heavy metals Zn, Cu, Pb and Cd in the various phases which are dissolvable, ion-exchangeable, combined with carbonates, easily-reducible, reducible, combined with organic matters and sulfides and residue in the sediments, have been obtained.     

离子交换—原子吸收光谱法测定海水中痕量铜、铅、锌、镉、铁、锰

本文介绍了用国产D401型螯合树脂分离富集海水中铜、铅、锌、镉、铁、锰等痕量元素,并用原子吸收光谱仪测定其含量的方法。讨论了各元素的分离条件选择及干扰元素的影响,并与溶剂萃取法的结果作了比较。各元素检测的定量下限为:铜0.5μg/L、铅0.1μg/L、锌1.0μg/L、镉0.01μg/L、铁2.0μg/L、锰2.0μg/L。方法精密度在4—8％之间,回收率为90—102％。     

图们江口水中Zn,Cd,Pb,Cu的形式分析

本文用防吸附物理涂汞电极反问极谱对图们江口、东海及日本海水中Zn,Cd,Pb,Cu进行了形式分析,其不稳定态的平均浓度分别为5.9,0.071,0.039,0.69ug/L(占总量的15～27％),分布较为均匀,证实了痕量金属离子(自由离子及不稳定络离子的均匀分布规律。有机结合态Zn,Cd及Pb(10～30％)和颗粒态Zn,Cu和Cu(15～40％)的较高含量位于长江口、东海及图们江口。     

长江口南岸边滩沉积物重金属污染记录的磁诊断方法

根据长江口南岸边滩南区排污口附近采集的柱样的磁性测量和重金属含量分析,探讨了磁性测量方法在沉积物重金属污染记录信息提取方面的应用价值,结果表明,磁性参数ｘＡＲＭ、ｘｆｄ％、ｘＡＲＭ／ｘ和ｘＡＲＭ／ＳＩＲＭ与重金属Ｃｕ、Ｚｎ、Ｐｂ、Ｃｒ具有极为相似的垂向变化特征,反映了细晶粒亚铁磁性太物对重金属的吸附作用,以及沉积物粒度组成对重金属含量的影响。根据上述相关性,建立了利用磁性参数推断重金属含量的影响,根据上述相关性,建立了利用磁性参数推断重金属含量的线顺归模型。不同柱样基于磁性参数ｘＡＲＭ的层位对比表明,不同部位沉积物中的重金属记录可以对比,但其含量却存在较大的差异,反映了重金属空间分布的复杂性,本项研究表明,作为一种辅助手段,磁性测量可以在分分辨率的重金属污染研究中发挥重要作用。     

长江口海域有害重金属转移机理——Ⅱ.粘土矿物对重金属吸附作用的热力学和动力学的实验室模拟研究

关于控制水体中重金属含量的因素,六十年代以来文献陆续有所报导.在海水体系中粘土矿物对重金属的固定作用的研究,较早期的有Chester(1965)的伊利石吸附海水中钴和锌的研究.近五年来又见有Rermers[1]、Murray[2]、Meyers[3]、O'conner[4]、Weijden[5]以及Robin[6]等进一步分别探讨了粘土矿物对重金属吸附作用的影响因素、吸附能力及吸附动力学等问题,其中有的还提出了吸附作用的模式.     

江苏王港潮滩重金属Pb、Zn和Cu的累积规律

对15年来江苏王港潮滩重金属Pb、Zn和Cu积累规律研究表明,王港潮滩WG05点位现代平均沉积速率为4.13 cm/a。王港潮间带重金属垂直方向的含量具有趋同性,从表层向下逐步降低,具有明显的表聚和亚表聚特征,王港潮滩Fe与Li的相关系数非常显著,超过了0.90,这些潮滩重金属来自岩石风化的可能性较大;Pb、Cu、Al则与铁元素呈负相关,表明王港潮滩沉积物中的重金属Pb、Cu的含量受人为因素的影响较大。归一化后,Cu、Zn的归一化值在15年内相当稳定,其中Cu的波动范围在0.4~2之间,Zn在1.5~2.6之间狭小的范围内波动;这说明王港潮滩的Cu、Zn积累主要来自于地壳风化,受物源和沉积环境等自然因素控制较大,受人类活动影响较小。而Pb归一化以后在4个柱状样中都表现出随时间的变化发生了较大的波动。Pb、Cu为该区域的主要污染因子。     

渤海湾及其附近海域沉积物中Cu,Pb,Zn,Cd环境背景值的研究

根据渤海湾及其毗邻河口区10柱岩芯样细颗粒（＜0．063mm）（GF 1983－1985年采集）中重金属含量特点，结合^216Pb年代学编年资料，用未受人类影响沉积层中元素含量，藉统计学方法获得渤海湾岩芯样中Cu，Pb，Zn，Cd的分布类型，并根据各区重金属的含量水平，用t检验法获得了渤海湾Cu，Pb，Zn，Cd的环境背景值。     

源解析受体模型在伶仃洋沉积物重金属污染研究中的应用

源解析受体模型是在大气气溶胶粒子来源及酸雨成因研究中建立与发展起来的。首次将该模型移植到水环境的沉积物重金属污染研究中，经验证处理后，解析了伶仃洋沉积物中重金属的地理区域源，并定量计算了这些区域源对特征污染元素的贡献率。     

连云港近岸海域沉积物中重金属污染来源及生态评价

采用等离子体发射光谱法、冷原子吸收法、原子荧光光谱法及灼烧法测定了连云港海州湾近岸表层沉积物中重金属和有机质的含量,利用主成分分析法(Principal Component Analysis,PCA)研究了沉积物中重金属的来源,发现前3个主成分的贡献率分别为54.21%、19.04%、16.37%,表明重金属主要有3个来源:工业和生活污水排放、农业灌溉水的排放、有机质降解。以PCA计算结果为基础应用海洋沉积物污染指数(Marine sediment pollution index,MSPI)和平均沉积物质量标准商数(Mean sediment quality guideline quotient,SQG-Q)评价了沉积物中重金属的污染状况及对生物的潜在影响。结果发现,海州湾近岸海区沉积物质量污染严重(MSPI值在60到80之间),排污口海区的沉积物污染最为严重(MSPI值大于80),连云港近岸海域沉积物对生物的负影响潜力为中度水平(0.1SQG-Q1)。     

长江口北支表层沉积物重矿物分布和磁学特征

分析了长江口北支表层沉积物的重矿物分布,结合磁参数和粒度特征,探讨其在各沉积动力分区的分布特点及控制因素.研究表明:研究区重矿物以角闪石和绿帘石组合为主,其次为云母类和磁铁矿等.其中浅滩和潮流脊处水动力较强,沉积物颗粒较粗,重矿物以片状矿物-稳定矿物组合占优势,磁性参数相对较低;汉道和潮汐通道处水动力相对较弱,沉积物以...     

重金属镉、铅、铜和镍在非洲鲫鱼体内的积累、分布和排出

海洋生物对重金属有相当强的累积能力,它们对海洋中重金属的分布和迁移过程中起着重要的作用。许多学者在这方面进行了研究,但试验材料主要是无脊椎动物。Wright,Heit等曾对鱼体中若干重金属含量进行过测定分析。瑞典人首先使用狗鱼Esox lucius作为河口淡水和半咸水汞污染的指示生物。Dix等也建议用鲬Platycephalus bussensis作为海洋汞污染的指示生物。然而由于室内饲养困难等原因,对鱼类进行实验室内     

深圳福田白骨壤红树林Cu,Pb,Zn,Cd的累积及分布

于1994年3月，采用样方法分析、探讨深圳福田自然保护区车公庙林区白骨壤红树林重金属Cu，Ph，Zn，Cd元素的累积及分布。结果表明：该林地表层土壤（0—3cm深），Cu，Ph，Zn，Cd的含量分别为383．28．7，1140，0136×10－6，储量分别为5285.40，3960.60,15732.00,18.77mg／m2、植物体各部位Cu，Pb,Zn，Cd含量范围分别为1.81-13.8，0.402－3．51，3．42－69.5，0.013－0295×10-6对表层土壤加权平均富集系数为Cd＞Zn＞Cu＞Pb.该群落Cu，Pb，Zn，Cd现存累积量分别为53．70,19．27，187.89,0.72mg／m2；年净存留累积量分别为4063.91，1318.14，16358.62，60．21μg／m2；林地残留物相应元素的储量分别为2091.18，1958.66,5046.60,19.30μg／m2。该林区不同群落叶层Cu，Pb,Zn，Cd现存累积量为白骨壤林＞桐花树林＞秋茄林。     

长江口海域悬浮颗粒物中铜、铅、镉的化学形态及分布特征研究

研究了重金属Cu,Pb,Cd在长江口及其邻近海域悬浮颗粒中各化学形态间的含量,及其在长江内河段—河海混合界面—海区间的各形态间的迁移转化特征。结果表明,长江口海域中重金属以非残渣相为主要存在形式,其中铁锰氧化物为重要的清除载体;以铁锰氧化物和碳酸盐形式存在的重金属含量受水环境盐度和pH控制;通过多元回归计算求得重金属与pH值、盐度(X_s)、悬浮体(X_(s.s))的多元一次方程。     

深圳大鹏湾、珠江口海水有害重金属分布特征

本文利用“深圳—珠海近岸海洋地质环境调查及地质灾害防治的调查研究”项目海水样品有害重金属测试数据,分析了深圳大鹏湾、珠江口海水有害重金属的分布特点,并与沉积物中的有害重金属含量进行综合比较,最后根据国家标准进行了水质评价。结果表明,研究区有害重金属含量、比例以及分布特征不尽相同,深圳大鹏湾超标有害重金属主要是Cr^＋6、Cu、Pb,珠江口则主要是Pb、Cr^6＋,其中以Pb是超标最为严重,其来源不仅与地球化学本底值有关,也与人类活动直接联系。