Annual ambient atmospheric mercury speciation measurement from Longjing,a rural site in Taiwan

The main purpose of this study was to monitor ambient air particulates and mercury species [RGM, Hg(p), GEM and total mercury] concentrations and dry depositions over rural area at Longjing in central Taiwan during October 2014 to September 2015. In addition, passive air sampler and knife-edge surrogate surface samplers were used to collect the ambient air mercury species concentrations and dry depositions, respectively, in this study. Moreover, direct mercury analyzer was directly used to detect the mercury Hg(p) and RGM concentrations. The result indicated that: (1) The average highest RGM, Hg(p), GEM and total mercury concentrations, and dry depositions were observed in January, prevailing dust storm occurred in winter season was the possible major reason responsible for the above findings. (2) The highest average RGM, Hg(p), GEM and total mercury concentrations, dry depositions and velocities were occurred in winter. This is because that China is the largest atmospheric mercury (Hg) emitter in the world. Its Hg emissions and environmental impacts need to be evaluated. (3) The results indicated that the total mercury ratios of Kaohsiung to that of this study were 5.61. This is because that Kaohsiung has the largest industry density (~60 %) in Taiwan. (4) the USA showed average lower mercury species concentrations when compared to those of the other world countries. The average ratios of China/USA values were 89, 76 and 160 for total mercury, RGM and Hg(p), respectively, during the years of 2000–2012.     

封闭垃圾填埋场通过地表向大气释放汞的测定

利用动力学通量箱及自动测汞仪联用技术,于2004年3月中旬对贵阳市的一座封闭生活垃圾填埋场汞通过地表向大气释放的过程进行了研究。3个采样点的汞释放通量日均值分别为559.1、88.2、53.6ng·m-2·h-1,汞释放通量强度与表层基质中的汞含量密切相关,该测定值高于世界背景地区通量的1~2个数量级,说明封闭垃圾填埋场也是大气汞的潜在来源。汞释放通量呈现明显的昼夜变化规律,白天较高并在午间前后达到最大,而夜间降至最低。气相因子中光照强度与汞的释放过程相关性最高,其次分别是气温、相对湿度、地温和风速。氧化态汞的光致还原作用是可能垃圾填埋场Hg0生成的主要途径,降雨初期能促进地表汞的释放。     

汞的环境光化学

作为一种全球污染物,汞在水体、底泥、土壤、大气等介质中以各种不同形态存在.各种汞形态具有不同的理化特性及毒性.汞形态的转化对于汞的迁移、毒性、食物链富集放大效应等具有重要影响.光照在汞的形态转化中起着重要作用,主要涉及光氧化、光还原、甲基汞的光降解以及无机汞的光化学甲基化等四个方面.本文对不同环境介质中汞的光化学转化过...     

A 1955�C2004 record of Hg contamination in Dianshan Lake sediments, Shanghai

Measuring Hg levels of water sediments is one of the primary routes to assess the trend of the contamination. Little work has been carried out in the Yangtze Delta to track the trend of mercury contamination caused by Shanghai, which is one of the fastest growing economies in the world today. The mercury concentration in the sedimentary cores from Dianshan Lake, Shanghai is studied here. Results show that mercury transported to Dianshan Lake from emissions of coal combustion and non-coal sources in the Yangtze Delta was greater after 1979. We found also that before 1979 mercury levels changed less with time than after 1979. Before 1967 Hg levels were more variable than in the 1970s. Moreover, the mercury dissolved in river water and bound to particles of water that flow past downtown Shanghai is different from that observed in Dianshan Lake, which is located in upper Shanghai. This indicates that atmospheric Hg deposition is probably the main source of mercury in Dianshan Lake. These results are important for the establishment of environmental protections and pollution treatment proposals for mercury in similar areas of the world, as well as in Shanghai.     

Distribution,fractionation and risk assessment of mercury in surficial sediments of Nansi Lake,China

Nansi Lake is composed of four sub-lakes from north to south: Nanyang Lake, Dushan Lake, Zhaoyang Lake and Weishan Lake. An environmental pollution investigation was carried out to determine the fractionation, and pollution assessments of mercury (Hg) in surficial sediments from Nansi Lake. Results showed that the mean concentration of Hg was 3.1 times higher than its background value (0.015 mg kg^?1), and the high concentration of Hg which even reached up to five times than the background value in the part of Dushan Lake and Weishan Lake, which indicated that there are obvious spatial differences. The content of Hg was positively correlated with that of total organic carbon, and negatively correlated with that of pH and SiO₂ in surface sediments. An improved Tessier sequential extraction procedure was used to study the fractions of Hg in sediments. The results indicated that Hg existed primarily in the fraction of residual, which accounts for 58.4% of total mercury (THg), and the percentage of extractable Hg was only 1.93% of total mercury. High concentrations of mercury of non-residual phase were found in part lake area from the Nanyang Lake and the Weishan Lake, which indicating a higher potential ecological risk relative to the other lake areas. Based on the values of enrichment factor and geo-accumulation index, most part of Dushan Lake and Nanyang Lake and Weishan Lake were in a moderate pollution. And based on the fractionation of mercury, risk assessment code of Hg exhibited low risks to the environment in Nansi Lake.     

Urban sediment contamination in a former Hg mining district,Idrija, Slovenia

Road sediments from gully pots of the drainage system and stream sediments from local streams were investigated for the first time in the urban area of Idrija town, the central part of the second largest and strongly contaminated Hg mining district in the world. Hg concentrations in road sediments were lower than in stream sediments. They ranged from 16 to 110 mg/kg (Md = 29 mg/kg) for <0.125 mm particles and from 7 to 125 mg/kg (Md = 35 mg/kg) for <0.04 mm particles, while Hg concentrations in stream sediments ranged from 10 to 610 mg/kg (Md = 95 mg/kg) for <0.125 particles and from 10 to 440 mg/kg (Md = 105 mg/kg) for <0.04 mm particles. High Hg loadings in stream sediments were successfully linked with identified mercury sources (rocks containing mercury ore, areas of former ore roasting sites, ore residue dumps), because they are located in the drainage areas of streams, from which the sediments were collected. Links between Hg loadings in road sediments and identified mercury sources were not recognized. Solid phases of Hg were determined by thermo-desorption technique and are similar for both types of sediments. Results show the occurrence of three different forms: elemental mercury, mercury bound to matrix components and cinnabar. Approximately 50 % of Hg in samples consist of non-cinnabar fractions. This is important, since they are potentially bioavailable. An interesting new discovery according to previous research of environmental media from Idrija area by solid-phase Hg thermo-desorption technique is that elemental mercury was determined in almost all investigated sediments in minor amounts (Md = 3 %).     

High mercury bioaccumulation in Pacific salmons from the Sea of Okhotsk and the Bering Sea

Mercury (Hg) accumulation in fishes is a serious threat for food security because mercury induces dieseases. Here we studied the total mercury content in four species of Pacific salmon (pink, chum, sockeye and chinook), caught in the Sea of Okhotsk, the Bering Sea, and the Kuril oceanic waters. Results show that the lowest concentration of mercury was found in the pink salmon, and the highest was 5–6 times higher in sockeye. Hg concentrations exceed several times those in other species of Pacific salmon from the North Pacific     

广州市蔬菜地土壤-蔬菜中重金属Hg的含量及变化趋势

测定了95份土壤样品、94份水样以及292份蔬菜样品中汞的含量,探讨了广州市蔬菜地土壤-蔬菜中重金属Hg污染状况.发现蔬菜中的Hg含量与土壤中的Hg含量较为密切.广州市土壤、蔬菜中Hg的含量水平均比过去大幅度降低.蔬菜中Hg含量与其它城市比较,污染情况较轻,处于其它城市的中低水平.     

招远市区土壤及常见绿化植物汞污染特征

为查明长期黄金开采冶炼对城市汞污染的影响,以"金都"招远为研究对象,于2011年4月,采集了招远市区常见绿化植物柏树、落叶松、冬青的茎叶样品30份,并同步采集相应表层土壤样品34份。采用冷原子吸收法测定样品总汞含量,分析了土壤的理化性质。结果表明,招远市区表层土壤中汞含量范围为0.002~0.815 mg·kg-1,平均值为0.149 mg·kg-1。土壤汞含量与有机质呈极显著正相关,与p H、粗颗粒比例呈显著正相关关系,而与阳离子交换量、黏粒比例呈显著负相关。不同城市区域相比,处于金矿区污染源下风向、且与矿区距离较近的梦芝区土壤汞含量要显著高于其它区域。常见绿化植物茎叶汞含量范围为0.021~0.782 mg·kg-1,不同植物中的汞含量没有显著差异,但同种植物中茎、叶中汞含量存在极显著正相关。植物中的汞在各城市区域没有显著差异,与土壤汞含量也不存在显著相关性。研究结果显示,招远市区土壤和植物受周边金矿开采和黄金冶炼的影响,存在一定程度汞污染。     

Histochemical demonstration of mercury in the intestine,nephridia and epidermis of the marine polychaete Nereis virens exposed to inorganic mercury

Marine polychaetes Nereis virens (Sars) were exposed to 9 ppb Hg as mercuric chloride in the aquarium water. Concentrations of mercury in the water and in the worms were monitored using radiolabelled mercury. After 11 d, the average mercury concentration in the nereids was 8.41 ppm Hg and the bioconcentration factor was calculated to be 930. Accumulations of mercury in the tissues were made visible for light and electron microscopy by autometallographic silver enhancement. Mercury was demonstrated in the intestine, nephridia, epidermis and cuticula. In the intestine, mercury was found to be located predominantly in the apical part of the epithelial cells. In the nephridia, mercury deposits were apparent in the peritoneal cells of the nephridial tubules. Silver-enhanced mercury was also observed at the epicuticula, in the collagen fibres of the endocuticula and in the epidermal basal cells. Intracellularly, the observed mercury accumulations were localised predominantly in lysosomes. Extracellularly, mercury was observed in the basal laminae of the intestine and the epidermis, and also in the intestinal peritrophic membrane. How N. virens copes with mercury toxicity is discussed.     

植被在大气汞收支中作用的研究进展与展望

在汞的生物地球化学循环中,对于"源"和"汇"的认识还存在许多不确定性。大气汞收支不平衡的问题使得植被在汞循环中的作用日益凸现;开展植被在大气汞收支中作用的研究有助于为全球汞减排政策的制定提供参考。本文首先概述了植被中汞的来源和影响因素及其与大气汞的源汇关系;进而重点论述了植被参与大气汞收支的主要方式:凋落物沉降、生物质燃烧和植被表面与大气汞的动态交换,并阐述了植被在大气汞污染监测中的应用;最后在总结我国相关研究的基础上展望了未来的发展方向。     

Bioconcentration factors of mercury by Parasol Mushroom (Macrolepiota procera)

To examine bioconcentration factors (BCFs) of mercury by Parasol Mushroom (Macrolepiota procera) roughly similarly sized (a cap diameter) fruiting bodies of this fungus and underlying soil (0–10 cm) samples were collected at 15 sites in Poland between 1995 and 2003. The total mercury content of the individual caps and stipes of Parasol Mushroom ranged from 0.05 to 22 mg Hg/kg dry matter (d.m.) and from 0.05 to 20 mg Hg/kg d.m., while the means were from 1.1 to 8.4 mg Hg/kg d.m. and from 0.83 to 6.8 mg Hg/kg d.m., respectively. The caps generally contained higher concentrations of mercury when compared to stipes, and the means of the cap to stipe mercury concentration quotient ranged from 1.3 to 4.6. The range of mercury concentration in topsoil samples collected at the sites where the fruiting bodies were collected was from 0.01 to 0.54 mg/g d.m. (means ranged from 0.022 to 0.36 mg/g d.m.). The BCFs factors for total mercury varied from 0.52 to 470 for individual caps and 0.52 to 360 for stipes, while average values, depending on the site, were from 16 to 220 and from 7.6 to 130 for caps and stipes, respectively.     

Ambient air particulates and particulate-bound mercury Hg(p) concentrations: dry deposition study over a Traffic,Airport, Park (T.A.P.) areas during years of 2011–2012

The main purpose of this study was to monitor ambient air particles and particulate-bound mercury Hg(p) in total suspended particulate (TSP) concentrations and dry deposition at the Hung Kuang (Traffic), Taichung airport and Westing Park sampling sites during the daytime and nighttime, from 2011 to 2012. In addition, the calculated/measured dry deposition flux ratios of ambient air particles and particulate-bound mercury Hg(p) were also studied with Baklanov & Sorensen and the Williams models. For a particle size of 10 μm, the Baklanov & Sorensen model yielded better predictions of dry deposition of ambient air particulates and particulate-bound mercury Hg(p) at the Hung Kuang (Traffic), Taichung airport and Westing Park sampling site during the daytime and nighttime sampling periods. However, for particulates with sizes 20–23 μm, the results obtained in the study reveal that the Williams model provided better prediction results for ambient air particulates and particulate-bound mercury Hg(p) at all sampling sites in this study.

     

Atmospheric mercury emissions from polluted gold mining areas (Venezuela)

Soil, waste rock and mud from mercury-gold amalgamation mining areas of El Callao (Venezuela) are highly enriched in Hg (0.5–500 μg g⁻¹) relative to natural background concentrations (<0.1 μg g⁻¹). Mercury fluxes to the atmosphere from twelve polluted sites of this area were measured in situ (6 a.m. to 8 p.m.) using a Plexiglas flux chamber connected to a portable mercury analyzer (model RA-915+; Lumex, St. Petersburg, Russia). Mercury fluxes ranged between 0.65 and 420.1 μg m⁻² h⁻¹, and the average flux range during the diurnal hours␣was 9.1–239.2 μg m⁻² h⁻¹. These flux values are five orders of magnitude higher than both reported world background Hg fluxes (1–69 ng m⁻² h⁻¹) and the regional values, which are in the range 2–10 ng m⁻² h⁻¹. The flux results obtained in this study are, however, similar to those measured at Hg polluted sites such as chloro-alkali plants or polymetallic ore mining districts (>100,000 ng m⁻² h⁻¹). The results from this study also show that Hg emissions from the soil are influenced by solar radiation, soil temperature and soil Hg concentration. Our data suggest that solar radiation may be the dominant factor affecting Hg° emission since the major species of mercury in polluted soil is Hg° (85–97% of total Hg). The simple release of Hg° vapor is probably the dominant process occurring with incident light in the field. The apparent activation energy for mercury emission indicates that the volatilization of mercury mainly occurred as a result of the vaporization of elemental mercury in soil. The degree of Hg emission differed significantly among the soil sites studied, which may be due to variations in soil texture, organic matter content and soil compaction.     

Principal biogeochemical factors affecting the speciation and transport of mercury through the terrestrial environment

It is increasingly becoming known that mercury transport and speciation in the terrestrial environment play major roles in methyl-mercury bioaccumulation potential in surface water. This review discusses the principal biogeochemical reactions affecting the transport and speciation of mercury in the terrestrial watershed. The issues presented are mercury-ligand formation, mercury adsorption/desorption, and elemental mercury reduction and volatilization. In terrestrial environments, OH-, Cl- and S- ions have the largest influence on ligand formation. Under oxidized surface soil conditions Hg(OH)2, HgCl2, HgOH+, HgS, and Hg0 are the predominant inorganic mercury forms. In reduced environments, common mercury forms are HgSH+, HgOHSH, and HgClSH. Many of these mercury forms are further bound to organic and inorganic ligands. Mercury adsorption to mineral and organic surfaces is mainly dictated by two factors: pH and dissolved ions. An increase in Cl- concentration and a decrease in pH can, together or separately, decrease mercury adsorption. Clay and organic soils have the highest capability of adsorbing mercury. Important parameters that increase abiotic inorganic mercury reduction are availability of electron donors, low redox potential, and sunlight intensity. Primary factors that increase volatilization are soil permeability and temperature. A decrease in mercury adsorption and an increase in soil moisture will also increase volatilization. The effect of climate on biogeochemical reactions in the terrestrial watershed indicates mercury speciation and transport to receiving water will vary on a regional basis.     

Research progress on occurrence forms and microbial transformation of mercury北大核心CSCD

汞是一种高毒性且具有持久性的重金属污染物,汞污染的治理与修复在近几十年一直是国内外研究热点.了解微生物对汞赋存形态的转化作用,对汞污染的治理与修复具有重要意义.总结汞的不同赋存形态、毒性及对应的常用分析方法,其中甲基汞(methyl mercury,MeHg)是毒性最强的汞形态之一.环境中汞的化学形态能发生转化,尤其以微生物驱动的汞的甲基化、MeHg的去甲基化和汞的氧化还原最为常见.依据汞转化类型将汞转化相关微生物分为汞甲基化、MeHg去甲基化、汞还原、汞氧化等类群,将对应的汞转化作用机制分为基于hgcAB基因的汞甲基化、基于mer操纵子基因的MeHg去甲基化和Hg2+还原、胞内过氧化氢酶介导的Hg0氧化.微生物汞转化过程不仅受到pH和温度的显著影响,而且还受到汞的赋存形态和游离汞的浓度、微生物种/群结构与功能、矿物种类、中间体和次生产物及其交互作用的影响,基于此,提出正确客观表征汞的微生物转化过程需要综合分析微生物组和矿物组的变化规律及其交互作用的综合效应.针对酸性矿山废水(AMD)极端环境微生物汞转化研究的不足,未来的工作将聚焦结合多组学手段、同步辐射谱学和密度泛函理论(DFT)计算等分析技术研究汞赋存形态的微生物转化过程,分析和阐明汞转化中间体的键合作用方式和转化机制,从而为AMD汞污染的预防、治理和修复提供依据.(图2表2参107)     

Total mercury in marine species from the French coast of the Eastern English Channel

Mercury (Hg) in fish can present a potential risk to wildlife and human consumers. Mercury levels were determined in 12 fish species and 2 invertebrate species from the French coast of the Eastern English Channel collected in June and November 2012. Total mercury concentrations in the muscle tissues ranged between 0.04 and 1.63 µg g^-1 (d.w.). Dab and sandeel displayed a significant positive correlation between Hg concentrations and fish length. Seasonal differences in Hg concentrations were observed for dab and shrimp. The lesser weever showed significantly higher concentrations of Hg (0.97 ± 0.34 µg g^-1 d. w.) than all other species. Gobies and sprat, which had the smallest size, showed significantly lower concentrations than herring, whiting, pout and sardine. Among the considered species, flatfish such as dab, flounder, plaice and sole displayed intermediate levels of Hg. In the present study, the fish age expressed as specimen length seems to be one of the major factors governing Hg contents in muscle tissues. Finally, mercury concentrations in commercial fish from the Eastern English Channel were below the levels fixed by the European Union for total mercury in edible parts of fish products.     

一种新的真空冷原子吸收法测定汞

本文建立了真空冷原子吸收光谱技术测定汞的一种方法。在负压下用ＮａＢＨ４将酸性溶液中Ｈｇ（Ⅱ）离子还原成为金属汞。在室温下使用真空泵将基态汞原子直接吸入到真空石英炉内。本法给出了改善的灵敏度,检出限（３σ）是０．０６ｎｇ。重复１０次测定０．５ｎｇ汞,方法的相对标准偏差是３．０％,将本法应用到测定水系沉积物标准样品中汞的含量,分析结果是令人满意的。     

Glutathione-functionalized melamine sponge,a mimic of a natural antidote,as a quick responsive adsorbent for efficient removal of Hg(II) from aqueous solutions

Minamata disease is caused by methylmercury, which is produced by microorganisms from inorganic mercury ions, Hg(II), in the aquatic environment. Adsorption is a feasible method to remove Hg(II) from waters, but there are some drawbacks when using conventional adsorbents, for example, tedious solid–liquid separation, slow response, and excessive residual levels of mercury. In this work, a novel spongy adsorbent has been developed for Hg(II) removal via surface functionalization of melamine formaldehyde sponge by glutathione. This material mimics a natural antidote that removes trace heavy metals in the human body. Results show that the functionalized sponge displays a 99.99% removal efficiency for low concentrations of Hg(II) of 10 mg/L. As a consequence, the residual Hg concentration is lower than 0.005 mg/L, which is slightly below the standard for total mercury in drinking water, of 0.006 mg/L, formulated by the World Health Organization, and much lower that the discharge regulation standard, of 0.01 mg/L, set by the ministry of environmental protection of China. Adsorption kinetic studies indicate that the functionalized sponge has a fast response. Indeed, the adsorption equilibrium can be reached within 10 min, and about 80% of total adsorption capacities are reached in 1 min. Moreover, the maximum adsorption capacity of the glutathione-functionalized sponge is as high as 240.02 mg/g, as shown by adsorption isotherm. Overall our findings disclose the great potential of the developed sponge adsorbent for rapid and efficient removal of Hg(II) from water.