Hg-CEMS系统中元素汞发生器的溯源和质控方法研究

参考借鉴美国IEMGTP元素汞溯源协议中规定的4个溯源传递层级以及4种常用的成熟溯源质控方法，研究了在中国现有技术条件下，各种质控方法针对Hg-CEMS中元素汞发生器User generator进行质控的适用性。通过对不同质控方法的测试，显示通过可吸附元素汞的活性炭吸附管采样分析（美国EPA 30B方法）和通过汞渗透源两种对元素汞发生器进行质控的方法在中国目前是可行且科学、可靠的。同时对建立和完善中国的元素汞溯源协议和元素汞发生器质控方法提出了建议。     

地面水中ppt量级汞的测定要领

汞在水中的化学不稳定性,以及极易被器皿所吸附,使之地面水中ppt量级汞的测定带来不少困难。一些读者因使用我们研制的高灵敏的WGY—S_1型数字荧光测汞仪,不断来函来访,讨论如何掌握超痕量汞的测定要领。为此,我们将几年来对于这一测定的研究和实验总结成文,期望进一步得到交流。     

活性炭负载催化剂去除燃煤烟气中单质汞的研究

以贵州凯里褐煤进行燃烧实验,研究采用CoCl2(负载量20%)改性的活性炭去除烟气中的单质汞。颗粒态汞占烟气总汞的87%,而单质汞占气态汞的80.4%。改性活性炭吸附了气态汞中97%的单质汞,而吸收液只吸收了3%的单质汞。可见改性活性炭也能有效地吸附煤燃烧实验中的烟气汞。实验结果表明,煤中汞的释放率为59.5%,1kg的改性活性炭可以吸附208t煤所产生的烟气中的气态单质汞。     

塞曼原子吸收光谱法测定固定污染源废气中的汞

用PMS 30B型汞采样器采集固定污染源废气,再用塞曼原子吸收汞分析仪测定样品中的汞,高、低浓度汞标准样品测定结果均在标准范围内,相对误差分别为0和4.3%。汞吸收管对高、低浓度含汞废气的穿透效率表明,当废气汞质量浓度达到mg/m3级别时,穿透率仅为1.3%。用该方法测定稳定工况固定污染源废气中的汞,6次测定结果的RSD为5.9%,方法检出限为1.04 ng,当采样体积为20 L时,检出限为0.05μg/m3。实际监测表明,钢铁企业、燃煤电厂、垃圾焚烧厂废气中汞为0.07μg/m3~1 031μg/m3。     

燃煤电厂排放总气态汞连续自动监测技术的选择

介绍了汞连续排放监测系统和汞吸附管采样系统的主要特点,比较了不同仪器的测定原理、样品处理技术、检出限和测定汞的形态,报道了美国环境保护署认证中心关于两个系统的认证结果.建议将汞连续排放监测系统与汞吸附管监测系统两种技术联合用于我国燃煤电厂排放总气态汞的自动监测.     

镀金石英砂吸附-AMA 254测汞仪测定大气中痕量汞的研究

采用镀金石英砂来富集大气中的气态总汞,AMA 254测汞仪测定。结果表明,不同采样时间下的单级吸附管的吸附效率均在90%以上,采样40min时的相对标准偏差为5%左右。与巯基棉吸附和吸收液吸收方法的对比显示,该方法具有吸收效果好、多次采样的精密度高、操作简便并且可以再生重复使用等优点。运用该法,对徐家汇等几个地点的大气总汞进行了测定。     

金膜吸附-冷原子吸收光谱法测定空气中的汞

采用新型金膜吸附-冷原子吸收光谱法测定空气中的汞，在0μg/L～100μg/L范围内线性良好，相关系数为0．9991。方法检出限为1．6 ng/m3，RSD为0．5％～2．7％，测定两种不同浓度的汞标准样品，相对误差为6．1％和3．2％。与两种现行国标方法（巯基棉富集和高锰酸钾溶液吸附法）比较，该方法所需试剂种类少，操作简便、吸附效率好，加标回收率高。     

汞的冷原子吸收测定方法的改进

汞的冷原子吸收测定方法的改进于文柱吴桂英吴海娟（黑龙江省齐齐哈尔市环境监测站，齐齐哈尔１６１００５）为消除硅胶吸附汞对测定带来影响，可首先使硅胶达到对汞的饱和吸附状态后再进行测定。在实际测定时由于每次测定条件基本不变，分析前用比０．１００μｇ高的汞溶...     

东平湖不同粒径底泥沉积物中汞的形态分布

对东平湖底泥沉积物中重金属汞的总量和形态及沉积物形貌进行了研究.从粒径分布与沿程分布分析了汞元素的形态分布特征.结果表明,东平湖底泥沉积物的主要粒径<63μm,且沉积物颗粒粒径越小,其表面的吸附物越多.不同粒级沉积物中汞的存在均以可氧化提取态形式为主,汞的形态分布与沉积物粒径的相关性可能受到原生矿物及因粒度效应产生吸附差异的综合影响.汞形态的沿程分布特征表明,湖南采样点受污染严重,潜在危害较大.     

大气中有机汞样品的吸附采集及其解吸方法研究

用1:1的BOSP和DEGS色谱填料作为混合吸附剂,研究了大气中有机汞样品的吸附采集及其解吸方法,选择了最佳实验条件。     

Improving data quality on low level mercury wastewater analysis

In order to compare treatability test results evaluating low-level mercury (Hg) removal from oil refinery wastewater, improvements in Hg analytical methods were conducted at two US EPA certified analytical labs. The revisions in the analytical protocols improved Hg recoveries and hence enabled more reliable data interpretation and comparison for the specific wastewater tested. Nevertheless, significant differences between results from the two laboratories were identified in a split-sample experiment.     

大气中不同形态汞的采集和分析方法

作为一种环境优先污染物,汞对人体和其它生物毒性很大。大气是全球汞生物地球化学循环的重要场所。不同形态的汞由于理化性质不同,迁移转化过程及其对生态环境的影响也不同,准确测定大气环境中各种形态的汞对于了解其在大气中的行为具有重要意义。1990年以来,大气汞的采集和分析方法技术已经取得了长足进步,一些自动测汞仪、低汞空白和高时间分辨率的采样及分析技术相继出现,使得准确测定大气中不同形态的痕量汞成为可能。文章就国内外近10多年来在这些方面所取得的研究进展进行了回顾和总结,主要介绍了气态总汞、颗粒态汞、活性气态汞、甲基汞等的采集和分析方法。     

燃煤电厂烟气中汞的采集与分析方法

汞的测试技术包括采样和分析两部分,其中汞含量的分析方法已经相对比较成熟,限制测试技术发展的诸多问题主要来源于取样过程。根据不同的取样方式,将现有测试技术分为湿式采样分析法、干式采样分析法以及在线分析技术3种,重点介绍了3种方法的采样原理、系统构成、过程的影响因素以及适用范围。最后针对CVAAS、CVAFS、AES 3种汞含量测定技术在Hg CEMS测试系统中的应用进行了对比介绍。     

Atmospheric-particulates-bound mercury Hg(p) study at five characteristic sampling sites in Taiwan

The main purpose for this study is to observe the seasonal and month variations for particulates-bound mercury Hg(p) in total suspended particulates (TSP) concentration, dry deposition at five characteristic sampling sites during years of 2009-2010 in central Taiwan. The results show that the highest and lowest monthly average particulates-bound mercury Hg(p) concentrations in TSP were occurred in Dec. and Oct. at Gao-mei (wetland), Chang-hua (downtown) and He-mei (residential) sampling site. In addition, the results show that the highest and lowest monthly average particulates-bound mercury Hg(p) dry deposition was occurred in Feb. and Oct. at Quan-xing (industrial) sampling site. This study reflected that the mean highest particulates-bound mercury Hg(p) concentrations in TSP and mean highest particulates-bound mercury Hg(p) dry deposition were occurred at Gao-mei (wetland) and Quan-xing (industrial). However, the mean lowest particulates-bound mercury Hg(p) concentrations in TSP and mean lowest particulates-bound mercury Hg(p) dry deposition were also occurred at Gao-mei (wetland). Regarding seasonal variation, the order of mean-particulates-bound mercury Hg(p) concentrations in TSP in winter and spring were Gao-mei (wetland) > Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential). Finally, the order of mean-particulates-bound mercury Hg(p) dry deposition in fall, spring and summer were Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential) > Gao-mei (wetland).     

Mercury contamination in human hair and some marine species from Sfax coasts of Tunisia: levels and risk assessment

The aim of this study was to measure the mercury (Hg) contents of three marine fish and common seafood species (Diplodus annularis, Sarpa salpa and Sepia officinalis) at two sampling sites in the gulf of Gabes, i.e. Sidi Mansour (polluted site) and Kerkennah (control site). These species are frequently consumed by the population living at the Sfax coasts of Tunisia, particularly by the families of fisherman. Additionally, the hair mercury levels of 55 volunteers (28 women, 27 men) were analysed and the daily total mercury intake through the fish and seafood diet was estimated. The key findings were: (1) the mercury contents of the examined fish and seafood species frequently exceeded the regulatory guideline value of 0.5 mg/kg, (2) no site-specific differences in hair mercury contents were found, (3) fish and seafood consumption is probably the major contributor of mercury exposure in this population, (4) the daily mercury intake through frequent consumption of D. annularis exceeds the US EPA reference dose. Further studies are necessary to evaluate the health risks associated with such high mercury exposure levels in order to allow optimal counseling and therapy of the concerned population and to avoid future impairment of human health, particularly children's health.     

Do national advisories serve local consumers: an assessment of mercury in economically important North Carolina fish

Consumption of marine fish provides both benefits (lean protein, omega-3 fatty acids and essential nutrients) and risks (main source of mercury (Hg) exposure for humans). Mercury is a potent neurotoxin and the source of more fish advisories nationwide than any other toxicant. Despite the widespread nature of Hg, it is unknown whether local Hg contamination reflects national and regional levels often used as bases to inform consumers of potential fish consumption risk. Thus, the objectives of our study were to examine Hg levels of six commonly consumed marine species harvested locally off the North Carolina coast and to compare our results to published regional (Monterey Bay Aquarium's Seafood Watch List) and national (Environmental Protection Agency, EPA, and Food and Drug Administration, FDA) Hg averages, action levels, and guidelines. We found significant differences in Hg concentrations among collected species, and we identified correlations between Hg concentration and fish length and trophic levels. Collected mahi mahi and triggerfish were below the EPA fish tissue action level (0.3ppm). Wahoo and grouper exceeded the EPA action level but were below the FDA action level (1.0ppm). King mackerel had the highest Hg concentration among targeted species, exceeding both EPA and FDA action levels. Further, our local results were not always consistent with calculated averages from EPA and FDA databases for the same species, and although many of our findings were consistent with Monterey Bay Aquarium's Seafood Watch List (southeast region), recommendations based on Hg levels would conflict with recommendations they provide based on sustainability. We find regional and national averages are not always reflective of local Hg contamination and suggest local data may be needed to accurately assess consumer risk.     

Sampling techniques for the assessment of anthropogenic vapour and particulate mercury in the Brazilian Amazon atmosphere

A system, based on annular gold-coated denuders, was optimized and used in the atmospheric sampling of mercury in urban and rural sites of the Alta Floresta, a region in the Brazilian Amazon. Results showed that vapour phase mercury (Hgv) is dominant in samples collected in both sites. However, particulate mercury (Hg) may sometimes be significant at the urban site, with values representing up to 77% of the total Hg collected during sampling, but may also be insignificant at the same site, depending on the gold commercialization activity and, probably, on the meteorological conditions during the sampling period. The presence of mercury in both the vapour and particulate phases in the atmosphere of the urban site can explain the high mercury concentrations found in urban dust reported for some cities in the Amazon, and also the relatively high Hg concentrations found in soils adjacent to the urban centre of Alta Floresta. It appears that the urban dust of "garimpo" areas in the Amazon can act as an efficient adsorber of Hgv emitted by gold dealer operations during the purification process. Mercury emissions from gold dealer shops in the Amazon have been considered as a human health risk through the inhalation of Hg vapour. However, although true for indoor sites, the significant contribution of particulate phase Hg shown in this study in outdoor urban sites calls for a re-evaluation of the risk assessment estimates performed up to now in urban centres in the Amazon.     

热分解-冷原子吸收法测定土壤中汞

采用热分解处理土壤样品,用冷原子吸收法测定样品中的汞,通过优化固体测汞仪的分析条件、确定校准曲线的线性范围和样品的称样量,使该方法在0.025 mg/kg~1.50 mg/kg范围内线性良好。当取样量为0.2 g时,方法检出限为0.000 9 mg/kg,有证标准物质的测定结果在保证值范围内,高、低浓度标准物质6次测定结果的RSD分别为4.6%和4.8%。用热分解法与国标法同时处理样品并测定,其测定结果无显著差别。