Species of Trace Metals, Organic Residues and Humic Substances in Sediments From the Taiwan Erhjin River and Coastal Areas

Total organic carbon, humic substances, and the species of trace metals (including Cu, Zn, Pb, Cd, Cr, Mn and Fe) in six and seven phases, such as bioexchangeable (P1), skeletal (carbonates, P2), easily reducible (Fe and Mn oxides, P3), moderately reducible (crystalline Mn oxides, P4), organic matters with sulphides (P5), and detritus with minerals (P6) as well as organic with humic substances (PB4) and organic residues (PB6), were analyzed in sediments from the Taiwan Erhjin coastal (including river and estuarine) area, where places we found the copper pollution. Results indicate that higher percentages of P1 and P2 for copper, zinc, lead, cadmium and manganese in samples collected in March and September of 1990 were much higher than those in P3-P6. High percentages of chromium and iron in samples respectively collected in March and September of 1990 were found in P6. for the seven phase analysis, higher percentages of copper species in PB4 and PB6 as well as iron species in PB7 were observed. On the other hand, purified humic acid with the high contents of manganese and iron in humic acid as well as purified fulvic acids were generally found at the upstream stations; and low values at coastal stations. However, extremely high copper (as high as 1750μg g^-1, dry weight in fulvic acid and 820μg g^-1 in humic acid) and lead (821μg g^-1 in humic acid) concentrations with relatively high manganese and iron concentrations were observed in humic substances from the station near the copper recycling area. Comparing the results obtained from the Antarctic Ocean sediments with those from the Taiwan Erhjin Chi coastal sediments, the human impacts on the latter are evaluated.     

The potential leaching and mobilization of trace elements from FGD-gypsum of a coal-fired power plant under water re-circulation conditions

Experimental and geochemical modelling studies were carried out to identify mineral and solid phases containing major, minor, and trace elements and the mechanism of the retention of these elements in Flue Gas Desulphurisation (FGD)-gypsum samples from a coal-fired power plant under filtered water recirculation to the scrubber and forced oxidation conditions. The role of the pH and related environmental factors on the mobility of Li, Ni, Zn, As, Se, Mo, and U from FGD-gypsums for a comprehensive assessment of element leaching behaviour were also carried out. Results show that the extraction rate of the studied elements generally increases with decreasing the pH value of the FGD-gypsum leachates. The increase of the mobility of elements such as U, Se, and As in the FGD-gypsum entails the modification of their aqueous speciation in the leachates; UO₂SO₄, H₂Se, and HAsO₂ are the aqueous complexes with the highest activities under acidic conditions. The speciation of Zn, Li, and Ni is not affected in spite of pH changes; these elements occur as free cations and associated to SO₄² in the FGD-gypsum leachates. The mobility of Cu and Mo decreases by decreasing the pH of the FGD-gypsum leachates, which might be associated to the precipitation of CuSe₂ and MoSe₂, respectively. Time-of-Flight mass spectrometry of the solid phase combined with geochemical modelling of the aqueous phase has proved useful in understanding the mobility and geochemical behaviour of elements and their partitioning into FGD-gypsum samples.     

The potential leaching and mobilization of trace elements from FGD-gypsum of a coal-fired power plant under water re-circulation conditions

Experimental and geochemical modelling studies were carried out to identify mineral and solid phases containing major, minor, and trace elements and the mechanism of the retention of these elements in Flue Gas Desulphurisation (FGD)-gypsum samples from a coal-fired power plant under filtered water recirculation to the scrubber and forced oxidation conditions. The role of the pH and related environmental factors on the mobility of Li, Ni, Zn, As, Se, Mo, and U from FGD-gypsums for a comprehensive assessment of element leaching behaviour were also carried out. Results show that the extraction rate of the studied elements generally increases with decreasing the pH value of the FGD-gypsum leachates. The increase of the mobility of elements such as U, Se, and As in the FGD-gypsum entails the modification of their aqueous speciation in the leachates; UO₂SO₄, H₂Se, and HAsO₂ are the aqueous complexes with the highest activities under acidic conditions. The speciation of Zn, Li, and Ni is not affected in spite of pH changes; these elements occur as free cations and associated to SO₄ ² in the FGD-gypsum leachates. The mobility of Cu and Mo decreases by decreasing the pH of the FGD-gypsum leachates, which might be associated to the precipitation of CuSe₂ and MoSe₂, respectively. Time-of-Flight mass spectrometry of the solid phase combined with geochemical modelling of the aqueous phase has proved useful in understanding the mobility and geochemical behaviour of elements and their partitioning into FGD-gypsum samples.     

Application of fish index of biological integrity (FIBI) in the Sanmenxia Wetland with water quality implications

Long-term changes of fish biotic integrity in the Sanmenxia Wetland,North China,since the 1950 s were assessed using the fish index of biological integrity（FIBI）. The water and sediment quality was evaluated by the water quality index（WQI） and sediment pollution index（SPI）. The results showed that FIBI continuously decreased from 46 to 20 during the past 5 decades,which indicated that the fish community state shifted from fair to very poor conditions,and damming by itself did not affect the fish biotic integrity. At the same time,WQI fell from 83 to 44.1,and SPI increased from 0.99 to 2.14 since the 1960 s,resulting from fast regional socio-economic development and insufficient wastewater treatment. Correlation analysis suggested that water quality significantly affected biotic integrity（r = 0.867,p 〈 0.05） through direct effects on the fish community. As a representative example of many wetlands in North China,our study clearly demonstrated that the biological integrity was degraded,induced both by water quality deterioration and sediment pollution,further driven by the contradiction between rapid development of regional economy and lagging development of sewage treatment facilities,which were thought to be the main factor responsible for the degradation of biological integrity.     

Investigation of trace element atmospheric pollution by nuclear analytical techniques at a global scale: harmonized approaches supported by the IAEA

In the framework of the IAEA programmes, Member States involved in air pollution studies using nuclear analytical techniques have harmonized their methodologies. Participants characterising chemical composition of size fractionated airborne particulate matter based their methodology on a common type of air sampler, centralised data collection and evaluation, and the same kind of data processing. Institutions involved in biomonitoring air pollution identified appropriate organisms to be applied at a regional scale, and harmonized procedures for sample preparation and analysis, as well as data processing and presentation. Both metrology approaches have been validated and disseminated in many Member States.     

Comparison of trace element concentrations in livers of diseased, emaciated and non-diseased southern sea otters from the California coast

Infectious diseases have been implicated as a cause of high rates of adult mortality in southern sea otters. Exposure to environmental contaminants can compromise the immuno-competence of animals, predisposing them to infectious diseases. In addition to organic pollutants, certain trace elements can modulate the immune system in marine mammals. Nevertheless, reports of occurrence of trace elements, including toxic heavy metals, in sea otters are not available. In this study, concentrations of 20 trace elements (V, Cr, Mn, Co, Cu, Zn, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb, and Bi) were measured in livers of southern sea otters found dead along the central California coast (n = 80) from 1992 to 2002. Hepatic concentrations of trace elements were compared among sea otters that died from infectious diseases (n = 27), those that died from non-infectious causes (n = 26), and otters that died in emaciated condition with no evidence of another cause of death (n = 27). Concentrations of essential elements in sea otters varied within an order of magnitude, whereas concentrations of non-essential elements varied by two to five orders of magnitude. Hepatic concentrations of Cu and Cd were 10- to 100-fold higher in the sea otters in this study than concentrations reported for any other marine mammal species. Concentrations of Mn, Co, Zn, and Cd were elevated in the diseased and emaciated sea otters relative to the non-diseased sea otters. Elevated concentrations of essential elements such as Mn, Zn, and Co in the diseased/emaciated sea otters suggest that induction of synthesis of metallothionein and superoxide dismutase (SOD) enzyme is occurring in these animals, as a means of protecting the cells from oxidative stress-related injuries. Trace element profiles in diseased and emaciated sea otters suggest that oxidative stress mediates the perturbation of essential-element concentrations. Elevated concentrations of toxic metals such as Cd, in addition to several other organic pollutants, may contribute to oxidative stress-meditated effects in sea otters.     

Monitoring of Gin Drinkers' Bay landfill,Hong Kong: II. Gas contents,soil properties,and vegetation performance on the side slope

This second part of the study concerned the plant cover, gas contents, and soil properties of the side slope area of the landfill, which is not protected against gas infiltration. Five different sites on the slope and a control site outside the landfill were chosen, and pipes were installed in the region. Gas contents were tested, and plant cover recorded by quadrat analysis Over 20 species of grasses, herbs, and vines were present on the slope The relative adaptabilities of the species were ranked according to the abundance of the plants Plant cover was found to be negatively correlated with landfill gas contents. The landfill soil had elevated contents of nitrogen, organic carbon, and extractable metals Total nitrogen, ammonia nitrogen, and extractable lead were further identified to be negatively correlated while available phosphate was positively correlated with plant cover     

人发中微量钴的分光光度测定

本文应用显色剂5-(2＇-噻唑偶氮)-2,4-二氨基甲苯(简称2,4-TADAT)测定了人发中的钴,方法操作方便、选择性好,获得满意结果.     

Thermodynamic analysis of the role of chlorine and sulfur environments during combustion and incineration processes

 In order to control the emission of trace metals from combustion and incineration systems, sorbents and filters are sometimes used. However, the effectiveness of these methods is greatly affected by the volatility of the metals and the way in which they speciate during combustion, and afterwards during condensation, and physical or chemical sorption. Although there has been a lot of research into the mechanisms by which trace metals speciate and subsequently appear in submicron particles, the details of these mechanisms are not yet thoroughly understood. In this study, a chemical equilibrium approach was used to qualitatively determine the speciation of lead, cadmium, and chromium in Cl and S environments. The reaction conditions of sorbents were also tested numerically in order to understand the reaction behavior of metals with sorbents. This article reports the influence of different concentrations of Cl and SO₂ on Pb, Cd, and Cr speciation, as representatives of other trace elements. The partitioning behavior of metals during combustion was also examined for Cl and S. The results obtained indicate that most metals exist in the vapor phase, even at low temperatures, when chlorine is present. However, the addition of SO₂ enhances the formation of the condensed phase, except at extremely high temperatures. This observation was not significant for Cd or Cr. The higher the concentration of Cl the higher the retention of trace metals in the vapor phase, even at low temperatures. Results from comparisons of the reactivities of mixed metals with Cl indicate that the presence of Fe limits the reactivity of most trace metals with Cl except at higher concentrations. In the presence of Fe, alkali metals are the first to react with Cl. If Fe is not present, most trace metals react with Cl, and the activity increases with higher concentrations. On the other hand, the partitioning characteristics of S show that its presence generally means that metals remain in the condensed phase. Sulfur is more reactive with alkali metals than with other trace metals. Received: June 6, 2001 / Accepted: April 30, 2002     

ICP-MS法测定地下水中痕量元素的条件选择

采用氦气碰撞模式和内标法抑制ICP-MS测试地下水中痕量元素的多原子离子干扰和基体效应。探讨He流量、内标元素、宏量离子等因素对测定的影响,结果表明:187Re、208Pb响应值与He流量呈线性下降模型,其他离子为指数下降模型,He流量为2. 5 m L/min～3. 0 m L/min时满足地下水质量分级测定要求;内标元素的响应因子随质量浓度的增大而降低,16. 0μg/L以上时趋于稳定;酸度显著影响测定误差,选用较大质量数的内标元素和保持样品酸度的一致可提高测定的准确度。