直接测汞法和原子荧光法测定土壤中总汞的比对研究

采用DMA-80直接测汞技术,与国标方法原子荧光法对土壤中总汞的测定进行了方法比对研究。试验结果表明,直接测汞法的检出限优于原子荧光法,精密度和准确性能够满足土壤实际样品的测定,对30个实际样品分析结果的比对表明,方法间无显著差异,该方法快速、准确、无污染。     

南京市冬季大气颗粒态汞的分布特征

采集了南京市2012年冬季4个功能区的PM2．5、PM10、TSP样品,对不同粒径大气颗粒物中的颗粒态汞测试。结果表明,南京冬季大气颗粒物TSP中汞的质量浓度为49．26 pg/m3～257．14 pg/m3,平均质量浓度为161．27 pg/m3;PM10中汞的质量浓度为44．82 pg/m3～228．29 pg/m3,平均质量浓度为147．38 pg/m3;PM2．5中汞的质量浓度为35．98 pg/m3～178．58 pg/m3,平均质量浓度为104．10 pg/m3。不同功能区大气颗粒态汞质量浓度的分布趋势为：交通综合区＞旅游区＞住宿综合区＞商业区。大气颗粒态汞60％以上存在于可吸入肺的PM2．5中,细颗粒物富集汞的能力比粗颗粒物强。     

上海市公园绿地常见落叶树木叶片汞浓度时空特征及环境意义

植物叶片汞浓度与大气气态单质汞(GEM/Hg0)浓度的线性关系表明叶片汞浓度大小可用于指示植物生长区内GEM浓度的高低水平.通过分析上海市绿地公园(25座)中常见落叶树木樱花、水杉、法桐叶片汞浓度的时空变化特征,探究区域内GEM含量水平及分布特征.2017年5-10月对7座公园中这3种树木叶汞浓度进行连续监测,结果显示...     

兰州城区大气粒子态汞的污染状况

通过调查发现在市工业区，粒子态汞浓度高，冬，夏平均值为０．９１和１．００ｎｇ／ｍ＾３，最高达１．９２ｎｇ／ｍ＾３，冬夏季无显著性差异，秋季浓度低，交通频繁区和交通商业混合区冬季平均值０．４５ｎｇ／ｍ＾３，夏季０．４９ｎｇ／ｍ＾３在清洁区大部分在０．１０ｎｇ／ｍ＾３左右，最低０．０７０ｎｇ／ｍ＾３，显示夏季和城区粒子态汞浓度偏高的特征。工业区粒子态汞主要是由人为污染产生的气态汞吸附在同一污染源的粒尘     

Gold Mining: Is It Worth Its Weight?

Gold (Au) accounts for only 0.004 g/ton of the earth's crust and is the most desired element. With an average annual world production of approximately 2,500 tons, the current methods of Au mining in developing countries cause major environmental issues. These issues vary from deforestation to cyanide and mercury (Hg) contamination. This article presents several cases of environmental catastrophes caused by Au mining in different regions of the world (Africa, the Middle East, Eastern Europe, and South America). It discusses the currently available processes for the large-scale extraction of metallic Au grains and supports the need for an alternative sustainable process.     

Total and Methylmercury in Soft Tissues of White-Tailed Eagle (Haliaeetus albicilla) and Osprey (Pandion haliaetus) Collected in Poland

Mercury (Hg) contamination in piscivorous birds, especially methylmercury (MeHg), has been drawing much attention worldwide in regard to its bioaccumulation and biomagnification in food chains. In this study on Hg in the soft tissues of white-tailed eagles (n = 22) and ospreys (n = 2) from Poland, total Hg (THg) range was 0.15–47.6 while MeHg range was 0.11–8.05 mg kg⁻¹ dry weight. In both species, median THg and MeHg concentrations were lower in the muscle and brain than in the liver and kidney. Median nephric residues were just under 3 and 5 mgTHg kg⁻¹ or 0.9 and 3.7 mgMeHg kg⁻¹ for white-tailed eagle and osprey, respectively. In Norwegian data from the 1970s and in our results, MeHg in the muscle of white-tailed eagle was ~60 % THg (%MeHg = MeHg/THg × 100), lower than in other piscivorous birds. A clear similarity in THg tissue levels was found between Polish and German populations of white-tailed eagles.     

Electrochemical study of the fungicide acibenzolar-s-methyl and its voltammetric determination in environmental samples

The electrochemical behavior of new generation fungicide acibenzolar-s-methyl (S-methyl 1,2,3-benzothiadiazole-7-carbothioate, ASM) on the hanging mercury drop electrode (HMDE) was investigated using square wave adsorptive stripping voltammetry. This method of determination is based on the irreversible reduction of ASM at the HMDE. The well-defined ASM peak was observed at ?0.4 V (vs. Ag/AgCl) in BR buffer at pH 2.2. The reduction peak current was proportional to concentration of ASM from 1.0 × 10^?8 to 6.0 × 10^?8 mol L^?1 with detection and quantification limit 3.0 × 10^?9 and 1.0 × 10^?8 mol L^?1, respectively. The applicability of the developed method for analysis of spiked samples of tap water, river water, and soil is illustrated. The effect of adsorption on the mercury electrode was studied in detail using the AC impedance method. Possible interferences with other common pesticides and heavy metal ions were examined. Clarification of the electrode mechanism was made using cyclic voltammetry (CV) technique.     

Contamination of wild-grown edible mushrooms by heavy metals in a former mercury-mining area

The aim of this study was to evaluate the contamination of six edible wild species of mushrooms (Boletus pulverulentus, Cantharellus cibarius, Lactarius quietus, Macrolepiota procera, Russula xerampelina and Suillus grevillei) by heavy metals (Hg, Cd, Pb, Zn, Cu, Ni, Cr, Co, Mn and Fe). Mushroom samples were collected from sites contaminated by emissions from mining and processing of polymetallic ores in operation during the period 1969–1993 in Rudňany, southeast Slovakia. The four study sites spanned up to a 5-km distance from the emission source. The collected mushroom samples were analyzed using Flame Atomic Absorption Spectrophotometry and/or Flame Atomic Absorption Spectrophotometry with graphite furnace. Mercury, Cd and, in some samples, also Pb present the highest risks in terms of contamination of the food chain following subsequent consumption. The content of two metals in the dry matter (dm) of the mushrooms exceeded the limits set by the European Union (EU; Cd: 0.5 mg/kg dm, Pb: 1.0 mg/kg dm). The highest mean contents of the eight metals recorded for S. grevillei were 52.2, 2.15, 107, 104, 2.27, 2.49, 81.6 and 434 mg/kg dm for Hg, Pb, Zn, Cu, Ni, Cr, Mn and Fe, respectively. The highest content of Cd was recorded in M. procera (3.05 mg/kg dm) and that of Co in L. quietus (0.90 mg/kg dm). The calculated weekly intake for Hg, Pb and Cd shows that regular consumption of mushrooms from the studied area poses risks to human health.     

高压实新疆阿尔泰膨润土微观结构随吸力变化特征

采用压汞法(MIP)和扫描电镜(SEM)法,在自由和侧限状态下,试验研究了高压实新疆阿尔泰膨润土在不同吸力条件下的微观结构变化特征。吸力的控制采用了气相法和渗析(液相)法。研究结果表明:(1)低吸力范围内,自由膨胀和侧限条件下的高压实膨润土土水特征存在明显差异;(2)膨润土在自由和侧限状态下的水化过程中呈现出了截然不同的微结构变化特征。自由膨胀条件下,土的吸水膨胀量主要来自土中大孔隙的逐渐膨胀。侧限状态下,随着控制吸力的降低,膨润土的大孔隙逐渐被压缩,较小孔隙的数量不断增加,土中孔隙分布变得更加均匀。     

正交试验-硝酸微波消解-冷原子吸收法测定土壤中汞

应用硝酸微波消解土壤样品-冷原子吸收法测定土壤中的汞。通过正交试验,优化了土壤中汞的微波消解条件。并对干扰消除、方法精密度、加标回收、检出限进行了试验研究。在0～10μg／L范围内线性关系良好,方法测定下限为0．20μg／L,土壤中汞的检出限为0．005μg／g。该优化条件对汞含量为0．02—0．46μg／g的土壤样品,汞提取完全。建立了一种简便、成本低、干扰少、灵敏度高的方法。