无机硒测定过程中的盐效应及其解决方法     

姚庆祯  张经 《中国海洋大学学报(自然科学版)》2003,33(5):795-800

在无机硒的测定过程中 ,Se(VI)还原为 Se(IV)的过程中存在严重的基质效应 ,本文采用加入浓的Na Cl溶液来消除基质效应 ,取得较好结果。方法的检出限为 0 .0 9nmol/ L,对 Se(VI)含量为 0 .89nmol/ L和 3.42 nmol/ L的样品分析精密度为 5.4%和 3.3% ,回收率在 95%～ 1 0 5%范围内变动。在不同介质中工作曲线斜率的变动范围 <5%。  相似文献   

Iron speciation and biogeochemistry in different nearshore waters     

M. ztürk  N. Bizsel 《Marine Chemistry》2003,83(3-4):145

Different environmental conditions in various nearshore waters dynamically determine the speciation of iron, its solubility, removal and hence bioavailability to phytoplankton. The iron speciation, the impact of phytoplankton blooms and the effects of organic matter on iron speciation and transformation were studied in four different coastal systems: the Trondheim Fjord, Norway, which is a coastal system that is open to a vast riverine impact; Hopevågen, Norway, a pristine coastal basin, which has negligible river and anthropogenic impact; zmir Bay, Turkey, a Mediterranean embayment with heavily polluted eutrophic inner–middle section, and the oligotrophic outer section. In this paper, we compare iron speciation in these different coastal systems. While colloidal iron (ColFe) was the predominant species especially in the Trondheim Fjord and to some degree also in Hopavågen, Chelex labile iron (ClxLFe) and hydrophobic organic-iron complex (HpOFe) were predominate species in both the inner–middle and the outer section of zmir Bay. The impact of phytoplankton blooms on the ClxLFe was significant especially in the Trondheim Fjord, in the inner–middle section of zmir Bay and in Hopevågen.  相似文献   

Size fractionation of phosphorus (dissolved, colloidal and particulate) in two tributaries to Lake Lugano     

Sabine Hilger  Laura Sigg  Alberto Barbieri 《Aquatic Sciences - Research Across Boundaries》1999,61(4):337-353

  相似文献   

Natural and Enhanced Concentrations of Trace Metals in Sediments of Cleveland Bay, Great Barrier Reef Lagoon, Australia   总被引：1，自引：0，他引：1  

G.B Doherty  G.J Brunskill  M.J Ridd 《Marine pollution bulletin》2000,41(7-12):337-344

Natural variation in concentrations of Cd, Co, Cu, Ni, Pb, and Zn in sediments of Cleveland Bay can be modelled by linear regression by using the concentration of Al recovered by strong acid digestion as an independent variable. Samples that exceed the upper 95% prediction interval of regression models are classified as enhanced. Enhancement of trace metals occurs in the intertidal zone and near-shore sediments of western Cleveland Bay, in sites that are characterized by high accumulation rates of fine grained terrigenous sediment. There is a strong positive relationship between increasing enhancement of Cu and Pb and the recovery of these metals by weak HCl digestion, which suggests that for these metals the modelled enhancement is environmentally meaningful. In contrast, at least 60%, and generally greater than 80% of Cd is recovered by weak HCl digestion irrespective of modelled enhancement, and suggests that the statistically modelled enhancement of Cd may be more meaningful than weak HCl soluble concentrations.  相似文献   

Relation of asid-volatile sulfide and clay content of sediment to the bioavailability of zinc and cadmium: laboratory plus field experiment     

HAN Jianbo  WANG Juying  MA Deyi  QUAN Xie 《海洋学报(英文版)》2005,24(5):61-67

Organic matter and iron and maganese oxides have been considered as the major affecting factors for metals in anoxic or oxidized sediment. In recent research, clay and sulfide are found as major factors in oxic or oxidized sediments that might affect bioavailability of metals. To test this hypothesis, the influence of sulfide, measured as acid-volatile sulfide （AVS）, and clay content on the bioavailability of zinc and cadmium in sediments was examined. Laboratory simulative experiment and field verification experiment were conducted, showing that the bioavailability of zinc and cadmium is strongly correlated to AVS and clay content in sediments. Taking into account both AVS and clay parameters in sediments together can better indicate the bioavailability of zinc and cadmium rather than considering one of them alone.  相似文献   

长江口深水航道治理工程：一期工程Se标段施工简介     

徐鸿  侯书东 《海岸工程》2000,19(1):36-42

长江口水航道治理工程,是我国建国以来最大的水上基础设施项目,也是世界上罕见的河口航道治理工程,它采用双导堤、丁坝结合疏浚的工程措施,分期将原依靠疏浚维护的７ｍ航首对１２．５ｍ。全工程各类堤坝总长约１３３ｋｍ,航槽疏浚土方近２．５亿ｍ＾３,计划总工期８年左右,工程总投资约主１５５亿人民币,其中一期工程工期为３年,约３２．５亿元开工以来工程顺利。  相似文献   

武汉东湖沉积物中重金属生物有效性研究   总被引：6，自引：0，他引：6  

郑利  徐小清  金利娜 《湖泊科学》2003,15(4):319-325

沉积物中的酸挥发性硫化物(AVS)是预测厌氧沉积物中重金属生物有效性的重要参数,SEM/AVS大于1时沉积物中重金属具有潜在生物毒性,小于1时则无生物有效性. 本文研究了东湖三个不同污染负荷的站点的同步提取金属SEM(Cu, Zn, Pb, Cd, Ni, Co, Ag, Cr)和SEM/AVS的深度分布,研究表明东湖沉积物中主要重金属是Zn, Cr和Cu,约占SEM总量的90%. I站、II站沉积物中AVS是重金属生物有效性的主控因子之一,对重金属的深度分布影响较大,重金属不具有生物有效性;III站沉积物中AVS对重金属的深度分布影响较小,重金属具有潜在的生物毒性. 相关分析表明,I站、II站沉积物中Cr、Ni、Ag、Cd与AVS在P<0.05有显著性相关,AVS对这些金属的深度分布具有更强的控制作用;虽然两站沉积物中Cr的含量差别不大,东湖I站沉积物中Cr/AVS比值(0.02)显著高于II站(0.003),沉积物中Cr与硫化物的结合主要是受还原反应的影响.  相似文献   

太湖流域滆湖底泥重金属赋存特征及其生物有效性   总被引：1，自引：0，他引：1  

包先明  晁建颖  尹洪斌 《湖泊科学》2016,28(5):1010-1017

为了探讨太湖流域滆湖底泥重金属(Cd、Cr、Cu、Zn、Ni和Pb)的赋存特征及其生物有效性,对底泥重金属总量、形态以及生物富集量进行了分析.结果表明,6种重金属含量的空间分布表现为北部湖区最高,其次为南部湖区,中部湖区最低,重金属Ni、Cu、Zn和Pb含量显著高于沉积物背景值,分别是背景值的4.77、3.89、2.96和2.76倍,重金属总量与沉积物中的黏土成分含量具有显著相关性.采用三级四部提取法对重金属形态进行分析表明,6种重金属的生物有效态(弱酸结合态、可还原态和可氧化态之和)含量顺序为CdCuZnPbNiCr,其中Cd、Cu、Zn和Pb的生物有效态含量分别占总量的84.15%、78.47%、76.50%和64.29%.Cu和Zn在铜锈环棱螺中富集含量要显著高于其他金属元素.相关性分析表明,6种重金属中仅Cr和Pb的生物富集量与有效态含量具有显著相关性,这表明,重金属在生物体内的富集不仅与有效态含量有关,还与底泥重金属总量有关.因此,评价滆湖重金属的生态风险时需要综合考虑重金属的总量及生物有效态含量.  相似文献   

Study of chemical forms of phosphorus and their bioavailability in the sediments     

ZHENG Airong  SHEN Haiwei  Li Wenquan 《海洋学报(英文版)》2004,23(3)

Chemical forms of phosphorus in the sediments of the Daya Bay, the Zhujiang River estuary, and the Xiamen Bay are measured with extraction solutions of MgCl2, NaOH, and HC1. Their availabilities to Chlorella sp. and Isochrysis galbana are estimated by using sediments as the sole source of P in the bioassays. The results show that the contents of total phosphorus (TP) in these sediments are 449.3, 650.1 and 643.9 mg/kg, respectively. The contents of nonapatite inorganic P (NAIP) extracted with MgCl2 and NaOH from 3 sediments are 168.8, 146.6 and 118.1 mg/kg,respectively, and account for 18.3% ～32.6% of TP. The phosphorus extracted with HCl solution is greater than that extracted with NaOH solution and the lowest extracted P is MgCl2-extractable P. The greatest relative growth rates of Chlorella sp. and Isochrysis galbana cultured with sediments are in the range of 4.3% ～26.9%. The increasing biomasses of these algae correspond to NAIP andAAPP (the estimated algal-available particulate P). AAPP accounts for 42.4% ～78.2% of NAIP, 21.1% ～ 27.1% of total inorganic P, and 11.8% ～ 20.3% of TP, respectively.  相似文献   

沉积物中磷的存在形态及其生物可利用性研究   总被引：12，自引：0，他引：12  

郑爱榕  沈海维  李文权 《海洋学报》2004,26(4):49-57

用MgCl₂,NaOH和HCl对大亚湾的大鹏澳、南海的珠江口、厦门湾的胡里山沉积物进行了逐级提取和总磷分析,并以这3种沉积物为惟一磷源培养小球藻和球等鞭金藻,估算了藻类对沉积物中磷的可利用量.结果表明,3种沉积物总磷含量分别为449.3,650.1和643.9mg/kg;MgCl₂和NaOH提取的生物可利用的非磷灰石无机磷分别为168.8,146.6和118.1mg/kg.非磷灰石无机磷占总磷的18.3%～32.6%.3种提取剂对3种沉积物提取的磷是HCl提取相最大,NaOH提取相次之,MgCl₂提取相最小.小球藻和球等鞭金藻在3种沉积物中的最大相对生长率为4.3%～26.9%,两种藻在3种沉积物中的生长与非磷灰石无机磷和藻类可利用的颗粒磷量相对应.颗粒磷占非磷灰石无机磷的42.4%～78.2%,占沉积物中总无机磷的21.1%～27.1%,占总磷的11.8%～20.3%.  相似文献