羟基磷灰石吸附水溶液中Cd~(2 )的影响因素的研究   总被引：6，自引：0，他引：6  

刘羽  胥焕岩  黄志良  罗惠华 《岩石矿物学杂志》2001,(4)

对羟基磷灰石 (Hap)固定水溶性Cd2 的影响因素进行了较为系统的实验研究。实验表明 :去除率与Cd2 初始浓度呈负相关 ,在Cd2 初始浓度 <10mg/L时 ,与作用时间、pH值、Hap用量呈正相关 ,温度对去除率的影响较小。通过正交实验确定了最佳吸附条件 :Hap用量为 5g/L ,pH值为 6 ,作用时间 5min。  相似文献   

原子吸收法连续测定铋及氧化铋中铜铅铁镉镍   总被引：7，自引：2，他引：7       下载免费PDF全文

张耀春 《岩矿测试》2003,22(1):70-72

HNO3分解样品后，直接用火焰原子吸收法测定铋及氧化铋中铜、铅、铁、锡、镍。方法的检出限分别为Cu 0．22μg／g，Pb1．5μg／g，Fe0．39μg／g，Cd0．11μg／g，Ni0．34μg／g。与国标方法进行比较，分析结果基本一致，精密度试验，各元素的RSD(n＝6)≤5．2％。  相似文献   

Duration of soil cadmium and lead pollution from shale-based alum production     

Bo Bergbck  Mats Eklund  Ulrik Lohm  John Svidn 《Journal of Geochemical Exploration》1997,58(2-3)

The scope of this study is to assess the present impact from an historical emission source, in order to provide information on the duration of this metal pollution problem.The present distribution of cadmium and lead, emitted from a Swedish alumworks between 1726–1840, was studied in soils, sediments and ground water. The soil data imply that cadmium has disappeared from the surface soils during the 150 to 250 years that have passed since the emissions ceased. Lead concentrations of the soil are elevated only within 200 m from the site of the works. Further away, the lead concentrations are almost at background level. A possible explanation for this pattern, is that lead dispersed in large particles has not yet fully disintegrated and leached down the soil profile, in contrast to the smaller particles deposited further away.The metal concentrations in the ground water wells are slightly higher than the Swedish average but probably governed by the pH of the water, rather than the occurrence of large amounts of metals. Elevated lead concentrations were found in a few sediment samples in the river mouth downstream from the works. These elevated concentrations coincided with the abundant occurrence of small particles of used shale, indicating their origin.Cadmium is not found, at present, in the soil around the alumworks in concentrations substantially above background levels. Consequently, it is likely that the cadmium deposited in the area, has leached through the upper layers of the soil profile on its way to the sea sediments. Likewise, the lead concentrations in the soil beyond 200 m from the alumworks are not above background levels which indicate that losses through leaching have occurred at a rate of 0.5 to 1.5% yr⁻¹.Finally, comparisons with other long-term perspective studies give an opportunity to discuss the rate for the disappearance of an environmental problem.  相似文献   

阳极溶出伏安法同时测定痕量锡和镉   总被引：4，自引：1，他引：4  

熊治强  郝恩坤 《岩矿测试》1996,15(1):77-79

在ＨＣｌ－ＮＨ＿４Ｃｌ底液中，电解时间６０ｓ、电镀时间５ｓ、除氧３０ｓ的条件下，Ｓｎ和Ｃｄ有稳定的溶出峰。Ｓｎ和Ｃｄ的检出限分别为６．５μｇ／Ｌ和３．０μｇ／Ｌ，测定范围分别为１０～２００μｇ／Ｌ和５～１８０μｇ／Ｌ。对含Ｓｎ和Ｃｄ为２０μｇ／Ｌ的试液测定１０份，ＲＳＤ分别为５．６１％和４．８３％。方法用于实际样品测定，结果与文献方法相符。  相似文献   

云南金顶超大型铅锌矿区水系沉积物中镉的形态分析     

李航  肖唐付  朱长生  何立斌  宁增平  李大华  双燕  谭显龙 《矿物岩石》2008,28(2):107-112

金顶矿区长期的矿业活动造成矿区水系沉积物严重污染.通过沉积物中Cd的化学形态分析发现:矿区沉积物中Cd元素形态主要以可还原态为主,其次为可氧化态Cd、残渣态Cd和弱酸提取态Cd.沉积物中Cd的形态特征受污染源的控制.当沉积物受氧化矿为主体的污染源控制时,镉的弱酸提取态和可还原态相对较高(占总金属量的90%以上),而当沉积物受硫化矿为主体污染源控制时.镉的弱酸提取态和可还原态相对较低(仅占总金属量的20%左右).池江水系沉积物中Cd的弱酸提取态占相当大比例(占金属总量的18.8%),在表生环境中极易释放出来并污染水体,对矿区乃至矿区下游流域生态环境构成直接的危害.  相似文献   

Cadmium and manganese distributions in the Hudson River estuary: interannual and seasonal variability     

Min Yang  Sergio A. Sa  udo-Wilhelmy 《Earth and Planetary Science Letters》1998,160(3-4):403-418

Surface waters collected along the salinity gradient of the Hudson River estuary in four cruises between 1995 and 1997 were size-fractionated into particulate (>0.45 μm), ‘dissolved' (<0.45 μm), colloidal (10 kDa, 0.45 μm) and low molecular weight (<10 kDa) phases. Dissolved Cd concentrations (range: 0.11–1.19 nM) in surface waters of the estuary appear to have decreased fourfold (from an average of 2.36 to 0.61 nM) over a 23-year period, since the initial analysis of samples collected in the 1970s by Klinkhammer and Bender [Estuar. Coastal Shelf Sci. 12 (1981) 629–643]. This interannual decline reflects improvement in sewage treatment and the elimination of industrial Cd sources to the Hudson River estuary. In contrast, dissolved Mn levels (range: 0.033–1.46 μM) have remained relatively constant over the same period of time, suggesting that anthropogenic sources have very limited impact on Mn concentrations in the estuary. The concentrations of both Cd and Mn appeared to strongly depend on the season and/or river discharge. The highest concentrations were detected under low freshwater discharge, implying that limited hydraulic flushing allows a build-up of metals in the water column. Although the decline in Cd levels within the estuary reflects a reduction in the magnitude of anthropogenic inputs, mass balance estimates indicated that current sources of Cd to the estuary include sewage discharges (in the lower estuary around Manhattan) and diagenetic remobilization from industrial Cd deposited in sediments nearly 2 decades ago (in the upper estuary near Foundry Cove). Moreover, under low river discharge, the sources considered in our model (sewage, riverine input, atmospheric deposition, and benthic fluxes) could account for no more than 60% of the Cd exported from the lower estuary to the ocean. This suggests that undefined sources such as ground water and inputs from other watersheds (e.g., Long Island Sound and Newark Bay) may potentially influence the water quality of the New York Harbor. The size-fractionated metal concentrations indicated that most of the traditionally defined ‘dissolved' Cd and Mn consisted of <10 kDa molecular weight species. High molecular weight colloidal species of Mn accounted for about 50% of the dissolved fraction at the riverine end-member and <5% at intermediate and high salinities. Colloidal Cd accounted for <6% of the dissolved phase throughout the estuary. Unlike the non-conservative excess (relative to ideal dilution of river water and seawater) of dissolved Mn observed along the estuary, high molecular weight colloidal Mn appeared to be removed at the head of the estuary. The small contribution of colloidal Cd and Mn to the ‘dissolved' phase suggests that remobilization from suspended particulate phases and/or from sediments occurs through the formation of small molecular weight species.  相似文献   

Effects of heavy metal ions on larval Penaeus chinensis and comparative study on their elimination methods     

Yuan Youxian  Gao Chengnian  Zhang Duxi 《海洋学报(英文版)》1993,12(2):285-293

In order to establish a new method to eliminate toxicities of heavy metal ions to larval penaeid shrimp, the effects of copper, zinc, lead and cadmium ions on larval metamorphosis of Penaeus chinensis at each stage were determined in detail, and two methods eliminating toxicities were compared. The results indicate that sensitivity of larvae to heavy metal ions decreases in the order of nauplii, protozoea, mysis and postlarvae. The phytoplankton food can reduce, by chetating, the toxicities of heavy metal ions. Both EDTA chelation and PHMA absorption can be used to eliminate the toxicities effectively and there is no significant difference between the two methods. EDTA is harmful to larval P. chinensis at high concentration but affects neither survival nor metamorphosis at below 10 mg/dm3. It is preliminarily observed that copper and zinc ions at low concentration are beneficial to the development of larvae after protozoea stage. It is suggested that it is unnecessary to e-liminate the effects of heavy  相似文献   

Cadmium and mercury in Seine Estuary flounders and mussels: the results of two decades of monitoring   总被引：1，自引：0，他引：1  

Nakhle  K.; Cossa  D.; Claisse  D.; Beliaeff  B.; Simon  S. 《ICES Journal of Marine Science》2007,64(5):929-938

  相似文献   

亚心形扁藻超氧化物歧化酶活性对镉和铜的应答   总被引：3，自引：0，他引：3  

李信书  唐学玺 《海洋湖沼通报》2007,(3):75-80

以亚心形扁藻为实验材料,对不同浓度重金属镉(Cd2 )和铜(Cu2 )作用下亚心形扁藻的超氧化物歧化酶(SOD)活性的变化和膜脂过氧化作用进行了探讨,以期了解藻类抗重金属的机制。结果表明:随着Cd2 和Cu2 浓度的增加亚心形扁藻的SOD的活性逐渐升高,但高浓度Cd2 可导致SOD活性活性下降。膜脂过氧化实验结果显示,半抑制浓度的重金属处理72hr后,膜脂过氧化产物丙二醛(MDA)显著提高。用72h半抑制浓度的重金属处理亚心形扁藻随时间的变化关系表明,在最初的12hr内SOD活性被两种重金属离子诱导迅速升高,然后逐渐趋于平稳。总之,SOD活性的变化与重金属的种类、浓度和处理时间有关。  相似文献   

重金属Cd2+胁迫对近江牡蛎超氧化物歧化酶活性的影响     

江天久  曾淼  牛涛 《热带海洋学报》2006,25(6):63-67

探讨了将近江牡蛎抗氧化酶防御体系参数作为海洋重金属污染生物监测指标的可行性。在实验室条件下,研究重金属Cd2 胁迫对近江牡蛎Crassostrea rivularis鳃和消化腺组织超氧化物歧化酶(SOD)活性的诱导作用。结果表明,Cd2 对近江牡蛎消化腺组织SOD活性诱导的剂量效应呈抛物线型,而对鳃组织SOD活性诱导曲线呈非抛物线型,由于二者结构和功能的不同,前者的SOD活性高于后者;低浓度Cd2 (0.1mg.L-1)对近江牡蛎鳃组织SOD活性表现为显著诱导,中(0.5mg.L-1)、高(1.5mg.L-1)浓度Cd2 对近江牡蛎鳃组织SOD活性诱导呈先升后降的变化趋势;低、中浓度Cd2 对近江牡蛎消化腺组织SOD活性均表现为显著诱导,高浓度Cd2 对近江牡蛎消化腺组织SOD活性诱导呈先升后降的变化趋势。研究表明,对于水体中单一因子的Cd2 污染物而言,近江牡蛎消化腺组织中的SOD活性对其有一定的指示意义,但将其作为指标应用到实际养殖水体尚须进一步研究。  相似文献