Heavy metal contamination in western Xiamen Bay sediments and its vicinity, China

Concentrations of selected heavy metals (Cu, Pb, Zn, Cd, Cr, Ni and Fe) in surface sediments from nine sites in western Xiamen Bay and its vicinity were studied in order to understand current metal contamination due to urbanization and economic development in Xiamen, China. The sediment samples were collected in December 2004 and July 2005 respectively in order to examine temporal variations. In this study, we found that heavy metal concentrations in surface sediments sampled in the western Xiamen Bay and adjacent Maluan Bay and Yuandang Lagoon varied from 19 to 97mg kg(-1) for Cu, 45 to 60mg kg(-1) for Pb, 65 to 223mg kg(-1) for Zn, 0.11 to 1.01mg kg(-1) for Cd, 37 to 134mg kg(-1) for Cr, 25 to 65mg kg(-1) for Ni and 3.08 to 4.81% for Fe. Although all metal concentrations in sediments meets Chinese National Standard Criteria for Marine Sediment Quality, both metal enrichment factors (EF) and geoaccumulation index (I(geo)) show that Pb contamination exists in the entire study area and contamination of other metals are also present in some locations depending on the sources, of which sewage outlets and commercial ports are the main sources of contaminants to the area. This study shows that using the sediment quality standard criteria only to assess sediments cannot properly reflect sediment contamination. A multiple approaches should be applied for the sediment quality assessment.     

运用STOMP数值模拟器进行多空介质中尿素水解以及方解石沉淀数值模拟

遍布于美国能源部所辖野外场地的地下放射性核素和痕量金属污染对美国能源部的长期监管职能提出了最严峻的挑战。目前较有前景的一个原地固化污染物方法是利用尿素酶催化尿素水解,进而推动方解石沉淀及与之共同沉淀。运用STOMP数值模拟器实施一系列反应性溶质数值模拟来研究系统中水流、运移、反应与反应导致的介质性质变化之间的紧密的非线性耦合,并在研究中系统性增加反应系统的复杂度和物理-化学的非均质性以考察模拟效果。通过调整反应速率表达式中尿素酶浓度和沉淀反应常数,对尿素水解和方解石沉淀速率进行了敏感度分析。结果显示:尿素水解速率是矿物沉淀总量的决定性因素,沉淀物的空间分布既取决于水解速率也取决于沉淀速率;在一维水流柱6个空隙体积的时间段模拟中,观察到了5%的最大空隙度减少;当二维模拟中考虑一个低渗透性包裹体时,被改变的流场重新对生成的沉淀组成物进行了分布,形成了扭曲的反应锋面。模拟结果也显示沉淀在低渗透性区域边界上形成,这说明位于这个区域里面的污染物可能被囊裹而从流线中被隔离起来。     

模拟CO_2埋藏的煤储层元素迁移实验研究

采用高压超临界CO2地球化学反应器对CO2在煤储层中的地质埋藏进行模拟,利用电感耦合等离子体发射光谱仪(ICP-OES)以及电感耦合等离子体质谱(ICP-MS)分别对淋滤液和煤样中的10种微量元素进行测试,对煤中微量元素在CO2的地质埋藏过程中的迁移进行了实验研究。结果表明:在CO2的地质埋藏过程中对煤的有机组成和无机矿物等均具有改造作用,从而影响到煤中微量元素的赋存和迁移特征,Cr、Zn、Cu等元素迁移能力相对较强,而Co、Ba、V等元素相对较弱;元素迁移能力大小顺序为:CrZnCuNiCdMnCoBaV。     

豫北地区油气资源远景预测

利用卫星影像,结合布格重力异常、钻井、天然地震等资料进行综合地质解译。对豫北地区油气资源预测与分布进行了探讨。线性构造主要由NNE、NENNW、EW、SN向组成,环状影像主要有色调不同的各种圆形、长条形及不规则形等。对东明、汤阴、济源、中牟等断陷的地质构造格局和含油气远景提出评价。     

APPLICATION OF PATTERN RECOGNITION TO SPECIATION DATA OF HEAVY METALS IN SUSPENDED PARTICULATES OF URBAN AIR

In order to get a better knowledge of the air pollution levels of the urban air of Barcelona,twelvesamples from three stations of the air-monitoring control network were analysed.Each control station isrepresentative of a different environmental situation.Thus the station at Plaa Molina responds to asimple domestic and urban traffic situation;the station at Poble Nou to the influence of medium andsmall industries,mainly metallurgical;and the station at Montcada to a zone in which there existimportant industries,a cement factory,two highways and railroads.The total content of unsedimentable particles,three inorganic anions(chlorides,sulphates andnitrates)and six heavy metals(Fe,Pb,Cu,Mn,Cr and Cd)were determined on all the samples obtainedduring the same period of time.The use of an analytical scheme of sequential extraction has alsopermitted the subdivision of the total content of each metal into the following four fractions:(1)solubleor exchangeable;(2)associated with carbonates and/or with iron and manganese oxides;(3)bound toorganic matter;and(4)residual.The use of principal component analysis applied to the data as a whole showed the associations andcorrelations between the various parameters as well as between the different above mentioned fractions.The predominant presence of Cd in the‘soluble or exchangeable’fraction is confirmed,while the othermetals are mainly associated with the‘carbonates and/or Fe and Mn oxides’and‘bound to organicmatter’fractions.Hierarchical cluster analysis applied to the twelve samples showed clearly the presence of threedifferent classes closely related to the origin(station)of the samples.Thus it becomes feasible to proposefor each station a possible profile of the content in terms of the different parameters considered.     

Organochlorines and dioxin-like compounds in green-lipped mussels Perna viridis from Hong Kong mariculture zones

Concentrations of persistent organic pollutants including polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and dioxin-like compounds were measured in green-lipped mussels, Perna viridis, collected from seven mariculture zones in Hong Kong between September and October in 2002 in order to evaluate the status, spatial distribution and potential sources of pollution in these areas. Concentrations ranged from 300 to 4400 ng/g lipid weight for total OCs and 170–1000 ng/g lipid weight for total PCBs (based on 28 congeners). Relatively smaller DDT concentrations in mussels compared with previous studies suggest reduced discharges of DDTs from nearby regions into Hong Kong waters. Detection of a mixture of HCH isomers in the mussels indicated that Hong Kong waters were predominantly contaminated by technical HCHs rather than lindane. Mussel samples from all sampling locations elicited significant dioxin-like activity in the H4IIE-luc bioassay. The greatest magnitude of dioxin-like response (39 pg TEQ/g wet wt.) was detected in mussels from Ma Wan in the western waters of Hong Kong, which is strongly influenced by the Pearl River discharge. Human health risk assessment was undertaken to evaluate potential risks associated with the consumption of the green-lipped mussels. Risk quotient (RQ) for dioxin-like compounds was greater than unity suggesting that adverse health effects may be associated with high mussel consumption.     

Solar Stokes Spectrum Observation at Yunnan Astronomical Observatory

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Heavy metal pollution in sediments of a typical mariculture zone in South China

The heavy metal inventory and the ecological risk of the estuarine sediments in Hailing Bay, an important maricultural zone along the southern coast of China, were investigated. Results show that the surface sediments were mainly polluted by As (2.17-20.34 mg/kg), Ni (1.37-42.50mg/kg), Cu (1.21-58.84 mg/kg) and Zn (11.69-219.22 mg/kg). Furthermore, the aquafarming zone was significantly more polluted than the non-aquafarming zone, and cluster analysis suggested additional sources of heavy metal input in the aquafarming zone. As, Cr, Cu, Ni, Pb and Zn were mainly present in the non-bioavailable residual form in the surface sediments, whereas Cd was predominantly in the highly mobile acid soluble and reducible fractions. The ecological risk of the polluted sediments stemmed mainly from Cd, and from As, Cu and Pb to less degrees. The highest potential risks occurred near the aquaculture base, indicating the need to control heavy metal inputs from aquafarming activities.     

Distribution and controlling factors of phytoplankton assemblages in a semi-enclosed bay during spring and summer

The phytoplankton assemblages' patterns and their correlation to environmental factors were studied in Bohai Bay during spring and summer. Two zones, the northern (NWA) and southern (SWA) water area, were identified by cluster analysis based on their physical and chemical properties. Principal component analysis (PCA) showed that more phytoplankton species was found in the SWA with low nutrient concentration, while high phytoplankton abundance occurred in the NWA with high nutrient concentration. The seasonal variability in phytoplankton can be explained by water temperature, nutrient, and hydrodynamic conditions (includes mixing during spring and stratification during summer). Results of redundancy analysis (RDA) showed that silicate (SiO(4)) and soluble reactive phosphorus (SRP) were the most important environmental factors influencing the phytoplankton distribution during spring and summer, respectively. Hydrodynamics condition plays a key role in controlling variation of the environmental factors, which determined phytoplankton distribution in Bohai Bay.