Quantification of the risk associated with high levels of mercury pollution at Temirtau, Kazakhstan     

Huiwen HSIAO Susanne M. Ullrich Trevor W. Tanton 《中国地球化学学报》2006,25(B08):233-233

This research aims to establish the risks of hurnan exposure to modeling approach. The study site was located on the River Nura 1990s, an acetaldehyde production plant located in the industrial high environmental mercury levels, based on a quantitative risk in central Kazakhstan. From the 1950s until its closure in the mid city of Temirtau released mercury-containing wastewater into the river. River sediments are highly contaminated with mercury up to a distance of 25 km and beyond. In addition, a local power station released an estimated 6 million tonnes of fly-ash into the water and the mercury has become quite tightly associated with the ash deposits. River water, fish and agricultural land in the floodplain are also contaminated with mercury, yet the risks posed to the local population have not been evaluated to date. In June and July 2005, we took samples of soil, interior and exterior dust, drinking water, and food from individual households, communal areas and markets. Additionally, water and sediment samples and fish were taken from the river. Interviews were conducted with householders to establish their age and body weight, general living conditions and sources of irrigation and drinking water. A food frequency questionnaire （FFQ） was designed to investigate the frequencies of consumption of several common regional food items, including fish from the fiver and/or local market. Human hair samples were also collected to estimate the mercury bioburden and to enable the validity of the modeling approach to be established. The paper expands on the main pathways of contamination and looks at linkages between exposure pathways and mercury concentrations found in human hair. Uncertainties inherent in risk analysis as well as their influence on the relative importance of different exposure routes are also discussed.  相似文献   

Changes to cadmium associations in canal sediments on drying and oxidation     

Samantha R. Cook John M. Chamock Andrew Parker 《中国地球化学学报》2006,25(B08):247-247

The mainly 19th Century canal system in the UK, largely managed by British Waterways, has been increasingly brought back into operation over the last few decades, and is now widely used for both leisure, and, increasingly, transport. Both initial and routine dredging of the canal sediment is carried out and these sediments are generally disposed of to land. Because many of the canals were connected with primary industries, their sediments can locally be significantly contaminated with heavy metals, and the behaviour of these metals under differing redox conditions, when introduced into a new environment （i.e., on land） is of importance for environmental risk-assessment purposes. Canal sediments are often rich in sulfidic mineral phases, and we have attempted to quantify the influence of these sulfidic phases on the release and retention of metals in dredged canal sediments, using a combination of traditional chemical techniques （e.g. sequential extraction） and X-ray absorption spectroscopy （XAS）. Sediment samples have been collected from urban fresh-water canals, one in the British Midlands and one in Northern France. It appears from XAS that Cd is largely associated with oxygen in air-dried sediment, and with sulphur in vacuum-dried sediment.  相似文献   

亚利桑那州的巨型干裂缝     

Raymond  C．Harris  于小芳 《水文地质工程地质技术方法动态》2006,(6):33-35

自1998年以来，亚利桑那州地质调查局就收到许多州周边大范围多个分散地点出现新裂缝的有关报告。此前90年代中期，报告的大部分裂缝均是人们所熟悉的类型，即开采地下水造成地面塌陷引发的地裂缝。然而，这些新裂缝大部分被证明具有不同的诱因——富含粘土的土壤或沉积物的干燥或被烘干。通过绘制这些被报道裂缝的地图及观察其航空照片，结果显示，这些“巨型干裂缝（GDC）”要比预先想象的普遍的多，并且比由开采地下水引起的地裂缝广泛的多。通过绘制亚利桑那州这些巨型干裂缝的地图，最近完成的一项研究证明了勘测的结果。这篇文章概述了那篇报道。  相似文献   

Heavy metal contamination in the sediment of the Second Songhua River   总被引：1，自引：0，他引：1  

Chunye LIN Mengchang HE Baixing YAN Xiangchun QUAN Yuxiang ZHOU Wei GUO Zhifeng YANG 《中国地球化学学报》2006,25(B08):118-119

The Second Songhua River was subjected to a large amount of untreated effluent from petrochemical industries in Jilin City in the 1960s to the 1970s. The objectives of this study were to investigate the mercury and other heavy metal contamination in the sediment of the river. The river bottom sediment was sampled from the river segment between Jilin City to Haerbin City in 2005. Total concentrations of Hg, Cd, Cu, Cr, Pb, Zn, Ni, As, Sc, and major cations （A1, Fe, Mg, Ca, K, Na） in the sediment were measured by atomic fluorescence spectrometer, ICP-MS, and ICP-OES, respectively, following digestion with various acids. We found the concentrations of most elements in the uncontaminated sediment were significantly correlated to those of Sc.  相似文献   

Early diagenesis of nurtrients （C, N, P and Si） stored in sediments of two reservoirs in southwestern China     

Yuchun WANG Jun ZHU Congqiang LIU 《中国地球化学学报》2006,25(B08):161-162

Damming is a common anthropogenic intervention along the course of rivers, which is defined as ＂artificial-lake effect＂, both in China and across the world. Today as many as 48000 dams and/or reservoirs are in operation in the Changjiang River （Yangtze River） drainage area, and more are being constructed. While damming is well known to affect riverbome nutrient loads, and thus the riverine ecosystems owing to removal of carbon fixation, and removal of particles in reservoir sediments, there is limited information on the detailed early diagenesis of sediments in reservoirs including the regeneration processes of nutrients deposited in sediments and exchange flux across the sediment-water interface, which is important for mass balance of riverbome nutrients. In the present study, two large-size reservoirs, Wujiangdu Reservoir （WJDR） and Dongfeng Reservoir （DFR）, located on the main steam of the Wujiang River and with uniformity hydrography and discrepancy biogeochemical activity （e. g. primary production）, were selected for a comparative study on the detailed processes of nutrient regeneration. Water, pore water and sediment were sampled from these two reservoirs and dissolved organic carbon （DOC）, NH4^＋, NO3^-, PO4^3-, dissolved silica （DSi） in the overlying water and pore water, and total organic matter in sediments were determined. The results of correlation analysis suggested that in these two reservoirs, processes of nutrient regeneration near the sediment-water interface were significantly different. As a result of rapid decomposition of algae-derived ＂labile＂ organic matter in upper sediments, nutrient regeneration processes and upward fluxes in WJDR are dramatically stronger than those of DFR. NH4^＋ upward flux from sediment in WJDR was about 17 times higher than that in DFR. PO4^3- flux in WJDR is about 13 times above that in DFR. DOC flux in WJDR is larger that in DFR by 5 times, and DSi by 1 time.  相似文献   

Influence of humic acid on bioavailability of heavy metals in sediments     

Wenhong FAN Jun CHEN 《中国地球化学学报》2006,25(B08):261-261

The mimetic ocean environment and chemical method were used to research the bioavailability effect of humic acid on five heavy metals in sediment, including Cd, Cu, Zn, Pb and Ni. The sediment was separated into four containers with artificial seawater, and each of them had different concentrations of humic acid. The values of concentrations covered the whole range found in natural sediment （0.1%-10%）. According to the 48 hours LC50 of clam and distribution coefficient, metals were added in artificial seawater, and their speciation was determined at first and then after two days＇ incubation. It was found the bioavailability of heavy metals was reduced in the presence of humic acid. The obvious negative effect on Zn was observed, but the influence on Cd was not remarkable. In addition, the contents of Pb and Ni increased obviously in organic phase, and they are correlative with the concentrations of humic acid.  相似文献   

珠江口伶仃洋海底表层沉积物重金属污染及潜在生态危害评价     

石要红  梁开夏真 《南海地质研究》2006,(1):52-59

对珠江口伶仃洋海底表层沉积物中重金属的分布规律进行了研究，并利用瑞典科学家Lars Hakanson的潜在生态危害指数法对重金属的生态危害程度进行了评价。研究结果表明，珠江口伶仃洋西岸附近的海底表层沉积物的重金属含量大于伶仃洋东岸附近的海底表层沉积物的重金属含量，重金属Zn、Cu、Cr、Cd、As和Hg的含量总体上表现为由西北向东南逐渐减小。生态危害评价结果显示，研究区内除4个站位为生态危害中等外，其余47个站位为生态危害轻微，海底表层沉积物重金属的污染程度顺序为Cd〉Hg〉Cu〉As〉Pb〉Cr〉Zn．  相似文献   

河北西北部熔积岩特征及其地质意义   总被引：1，自引：0，他引：1  

白志达徐德斌  孙善平 《岩石矿物学杂志》2006,25(6):487-492

熔积岩是火山碎屑岩的一种特殊类型，由熔浆和未固结的湿沉积物两种组分掺杂混合而成。熔积岩的形成主要受炽热熔浆与未固结的湿沉积物接触时引起的淬碎或蒸汽爆炸作用以及寄主沉积物流体化作用控制，通常分布于熔岩流底部或前缘，也可分布于超浅成侵人体周围。据熔浆碎屑物的结构特征，冀西北熔积岩可分为流状和块状两种类型。流状熔积岩多是熔浆与细粒沉积物混合的结果，块状熔积岩大多与粗粒沉积物相关。正确鉴别熔积岩对确定沉积作用与岩浆作用的时序、研究盆地发展演化历史具有重要意义。  相似文献   

水成相沉积物细颗粒石英光释光综合生长曲线的建立与应用   总被引：1，自引：0，他引：1  

杨传成  陈杰  张克旗  刘进峰  王昌盛  雷生学 《地震地质》2007,29(2):402-411

选择中国不同地区的冲洪积相等水成相沉积物样品,根据其简单多片再生法(SMAR)测量数据建立了细颗粒石英光释光信号的综合生长曲线(Standardised growth curves,SGC)。对未知年龄的水成相沉积物细颗粒石英样品,通过测量其天然光释光信号和试验剂量响应信号,并利用上述SGC方程可计算出其等效剂量值。将此值与简单多片再生法(SMAR)测量结果相比较,统计得出对于天然等效剂量为12~65Gy的样品,其误差可达19%;对于天然剂量>65Gy的样品,其误差更大;对于等效剂量<12Gy的样品,最大误差也达25%。实验表明,应用这个SGC估计未知年龄样品的等效剂量值范围,再对样品采用简单多片再生法(或单片再生法)进一步测量,可大大节省测量时间  相似文献   

土壤及河流沉积物中Hg、As、Sb的同时测定     

汪志国  鲁安怀 《矿物岩石地球化学通报》2007,26(2):141-143

Hg、As、Sb是土壤和河流沉积物的常规测定项目。本文采用新型三通道原子荧光分析仪,建立了同时测定土壤和河流沉积物中这三种元素的新方法。通过优化仪器工作条件,选择合适的样品处置方法,得到Hg、As、Sb的检出限分别为0.03mg/kg、0.009mg/kg和0.03mg/kg,精密度分别为3.5%、7.8%和5.5%,准确度分别为95%～103%、91%～107%(加标回收率)和±6.4%。与现有测定方法相比,本方法的样品消化完全,实验简便,分析速度和准确度高,能充分满足分析要求。  相似文献