郑州市土壤与绿色植物中汞的分布特征

汞污染具有生物积累性,因而得到社会广泛关注。研究监测和评估了郑州市城区土壤和绿色植物叶片中汞浓度、分布、污染水平等。研究发现郑州市主城区土壤总汞浓度为0. 150～0. 958 mg/kg,平均浓度为0. 448 mg/kg;郑州市主城区绿色植物叶片总汞浓度为0. 017～0. 249 mg/kg,平均浓度为0. 107 mg/kg;土壤和叶片中汞浓度按功能区排序为交通枢纽区工业区商业区行政区高教区住宅区。采用地累积指数法对郑州市80个土壤样品的汞污染水平进行评估,结果显示60%受到轻度污染,35%受到偏中度污染,5%受到中度污染。研究较为全面地分析了土壤汞污染的现状及浓度,为郑州市土壤汞污染防治提供参考。     

270年以来大气汞的沉降—自然释汞源与人为释汞源之冰芯记录

水生生态系统的汞污染及其引发的甲基汞在生物体内聚集是全球重要的环境问题。汞污染的主要机理是大气汞的迁移,研究冰川中总汞的质量浓度,能很好地揭示大气汞沉降的历史记录。对怀俄明州(Wyoming)弗里蒙特冰川上游(the UpperFremont Glacier,UFG)冰芯的研究,显示了近270年自然源与人为源的大气汞释放。     

空气环境中汞污染物分析测试的技术进展

阐述了我国空气环境中汞污染的现状,介绍了几种空气环境中汞污染分析测试技术。     

美培育出清除汞污染的细菌

科技日报消息受到汞污染的环境对人和许多生物都有害,但一项新研究显示,用转基因技术培育的一种细菌,不仅可在含高浓度汞的环境中存活,还能清除汞,减少污染。     

两次金汞齐—冷原子吸收光谱法测定大气中的痕量气态总汞

本文作者在已有仪器的基础上进行简单改装，建立了两次金汞齐—冷原子吸收光谱法测定大气中的微量气态总汞的方法。研究表明，这种方法最低检出限为０．０５ｎｇ；１００μｌ饱和汞蒸气连续测定结果表明其相对标准偏差＜１．４１％。在０～２．０ｎｇ汞量范围内标准工作曲线线性关系良好。运用该法，对贵州省万山汞矿、丹寨汞矿、清镇汞污染农田、省农科院和中国科学院地球化学研究所等地大气气态总汞进行了测定。这种分析方法还可以运用到其它环境样品微量汞的测定。     

烟气汞在线监测现状及仪器性能评估初探

针对近年来燃煤烟气汞污染控制技术的进步，概述烟气汞分析方法，综述烟气汞在线设备及技术的发展现状。通过将电厂排放废气中汞的手工检测和在线监测结果比对，对国内外汞在线仪器进行性能评估。     

安徽某燃煤电厂周边土壤汞分布特征及风险评价

结合当地气象条件,采集了安徽某燃煤电厂周边地区的土壤,采用冷原子吸收法测定其汞含量,应用地统计学和地理信息系统方法分析了电厂周边表层土壤汞含量的空间分布特性,分析了土壤中汞与理化性质之间的相关性,并进行了风险评价。结果表明,电厂周边表层土壤汞含量范围为0.015~0.076 mg/kg,平均值为0.029 mg/kg,虽未超过国家允许的标准,但与当地背景值及安徽省土壤汞含量相比均有一定程度的增加;土壤汞含量的总体分布特征为除距排放源1~2 km的环形区域受影响最大外,污染程度随着与电厂距离的增大而递减,汞含量空间分布受主导风向影响呈现明显的条带分布。相比于单因子污染指数法和地累积指数法,潜在生态危害指数评价法能更好地反映燃煤电厂周围土壤中汞的污染水平和生态风险程度。土壤汞含量与土壤理化性质之间存在不同程度的相关性。     

基于实测的燃煤电厂烟气中汞排放水平浅析

简述汞污染和控制问题成为环境问题的新热点和前沿研究领域,介绍中国燃煤电厂烟气汞监测试点的基本情况。分析江苏省7家燃煤电厂煤中汞及烟气中汞排放水平,提出利用现有的除尘、脱硫、脱硝设施,能满足《火电厂大气污染物排放标准》中汞的排放限值要求。     

关于水质、底质总汞消解及汞蒸气防护的问题

汞是一种重金属、剧毒,易升华,在100℃以上的温度时,任何形式的汞盐都会挥发,即使用强酸和强氧化剂也难以完全固定。 一、水和底质总汞的消解 水中的汞主要以无机盐形式存在,通常用硫酸-过硫酸钾冷消解,其测定的空白值很低,回收率>95％,是较为理想的方法,用于海水和清洁的地面水域。由于冷消解是在常温下24小时,故汞不易挥发。还有KMnO_4-硫酸热消解法,用于受有机污染过的水域,能有效地将有机汞转化为无机汞。其测定的空白值比硫酸-过硫酸钾法高几倍,且回收率不好约50％～80％,     

基于燃煤电厂超低排放的汞分布特性研究

为掌握超低排放改造后烟气处理装置对汞分布的影响,选择6台有代表性的超低排放火电机组进行现场测试。通过对火电机组入炉煤、炉渣、飞灰、脱硫石膏、末端烟气等样品的测试,得出不同燃烧产物中汞的分布:底渣和湿除出水的汞含量极微;电除尘底灰中的汞所占比重相对较大,平均汞含量占燃烧产物中总汞的比例可达57.97%。依据质量平衡原理,计算出不同超低排放改造工艺路线对汞的协同脱除效率为87.26%~95.60%,并分析了不同污染控制设备对汞排放的影响。     

Mercury contamination-what we have learned since Minamata

Atmospheric cycling of mercury and other pollutants has become a major concern as industrialized countries have eliminated point discharges, sometimes by relocating the industries to underdeveloped and developing countries where point sources have become problems. Such circumventions may be to no avail in the long run as pollution continues to elevate levels of methylmercury in fish in waterways that are remote from direct contamination as well as where the source can be readily identified. Much has been learned about the cycling of mercury in the environment since human disabilities and deaths at Minamata, Japan, initially drew attention to the problem of methylmercury poisoning from the consumption of contaminated seafood in the 1950s. In that instance, methylmercury produced industrially concentrated to toxic levels in fish. As this manufacturing process was not used outside Japan, concern did not become immediate in other developed nations until the 1960s when it was established that mercury was not only biomethylated by microorganisms but also biomagnified through the food chain. Point sources to the waterways may have been eliminated too late to return the levels in fish to background because of the geochemical cycling of mercury through the environment. Despite decreases in domestic, industrial and agricultural point source releases over the last two decades, large quantities from non-point sources such as fossil fuel combustion, smelters, and incinerators are still being released. Much of this mercury is transported from the atmosphere to aquatic ecosystems and stored in sediments until it is again released to the water and atmosphere.     

北京市大气气态汞变化特征

采用Tekran 2537X大气汞分析仪在线测量北京市城区大气中气态元素汞(GEM,简称大气汞) 浓度,研究大气汞浓度随不同气象条件的变化特征。通过分析2016年10月—2017年9月大气汞监测数据发现,该监测点全年大气汞浓度为0.48～16.25 ng/m³,均值为(3.41±1.79)ng/m³。春季、夏季、秋季和冬季大气汞浓度均值依次为2.93 、2.95、4.27、3.37 ng/m³,其中,秋季大气汞浓度明显高于其他季节 。秋季大气汞浓度显著偏高可能由不利的大气扩散条件导致。大气汞夜间浓度显著高于白天浓度。同时,将大气汞与SO₂、CO及PM_2.5进行相关性分析,发现大气汞浓度变化趋势与SO₂、CO和PM_2.5呈显著正相关。结合风向和风速进行污染来源分析,得到该点位大气汞在西南和东北方向上受人为排放源影响较大。污染源类型分析表明,冬季大气汞与CO同源性强,主要来自本地供暖用煤。     

Exposure Assessment to Mercury Vapor in Chloralkali Industry

The aim of the study was to develop a sampling method aimed at individual sampling of mercury vapor and subsequent individualexposure assessment of the worker. Hopcalite available fromInowrocawskie Zakady Chemiczne (in Poland) was founduseful for mercury vapor sampling in active and passive individual samplers. However the sampling rate determined forpassive sampler in steady-state laboratory chamber cannot be usedunder fluctuating conditions of mercury vapor concentration andair movement typical for field measurement. In order to check comparativeness of passive and active sampling methods, sampleswere taken in the same time and individual samplers fixed toworker's clothes were used. Mercury vapor concentration wasmeasured at two chloralkali industries in Poland and the resultswere presented. Excessive exposure in both industries wasconfirmed by finding elevated mercury concentration in urinesamples from the workers.     

Total mercury status in an urban water body,Mithi River,Mumbai and analysis of the relation between total mercury and other pollution parameters

Mercury is a heavy metal which has garnered attention recently in India. Minamata Convention on mercury was established on October 2013 and was joined by India on September 30, 2014. India is seen as a major mercury pollution source after China according to many studies in the past. Various mercury pollution sites that are currently recognized in India are Kodai Lake, Kodaikanal, Tamil Nadu, and Thane Creek, Mumbai. Since 1992, chlor-alkali plants have been regulated to eliminate mercury cell process of manufacturing. Also, medical and health care facilities are discarding mercury-containing equipment and processes. Various anthropogenic sources of mercury to the atmosphere include combustion of fossil fuels, processing and mining of primary metal ores, cement manufacturing units, chlor-alkali plants, and use of mercury in various products like paints, electric switches, and relays. The hazard associated with mercury pollution becomes extremely serious when we consider its ability to be transported over long-range distances. Various atmospheric transport models suggest India and other Asian countries to be a major source of long-range transport of mercury to North America. Considering the hazards of mercury and its widespread presence in our life, a study on mercury pollution in an urban water body is conducted. This study deals with Mithi River located in Mumbai Metropolitan Region (19.0760° N, 72.8777° E) to study the total mercury in water and derive its relationship with other pollution parameters.     

贵州东部某燃煤电厂汞排放对周边环境空气及土壤的影响

结合当地气象条件,测定贵州省东部某燃煤电厂下风向环境空气汞浓度分布情况,同时测定该燃煤电厂周边表层土壤中汞含量,并对其污染程度进行评价,探讨了土壤汞与理化性质间的相关性。结果表明,该燃煤电厂下风向环境空气汞浓度远高于北半球大气气态总汞背景值,空气汞浓度在2.7 km范围内随距离的增大而增大,在2.7~5.0 km范围内汞浓度随距离的增大而减小。电厂周边表层土壤汞含量是贵州省A层土壤Hg背景值的8.5倍,存在中度到重度程度的污染,土壤Hg与土壤pH呈正相关性,但与土壤有机质未表现出相关性。     

Mercury in small Illinois fishes: historical perspectives and current issues

Documenting long-term trends in mercury deposition and/or accumulation is important in setting regulatory benchmarks, modeling contaminant transfer and flux, measuring success of environmental controls, and even assigning responsibility for pollution. We conducted a study to compare mercury concentrations in small fishes from “high-mercury” and “low-mercury” regions of Illinois, as well as to examine historic patterns of mercury availability using preserved fishes. Mercury concentrations were greater in four species of small fishes collected from a stream in a “high-mercury” region than in those same taxa collected from a stream in a “low-mercury” area in Illinois. Mercury concentrations in blackstripe topminnows (Fundulus notatus) declined dramatically between 1900 and 1961/2006 in the “high-mercury” stream, presumably due reductions in mercury releases from local and regional sources. Preserved fish had an apparent increase in mercury concentrations for up to 12 months, which is consistent with changes in mass and loss of proteins observed in other studies, and we recommend that recent samples be preserved for at least 12 months before comparison with older fluid-preserved material. Based on our results, further studies of mercury in small fishes in Illinois streams appear warranted.     

基于重心模型的湖南省雾霾时空分布特征及其驱动机制分析

作为长江经济带的重要组成部分,随着工业化的发展、机动车保有量的不断增多,湖南省仍面临较大的雾霾污染风险。选取2015—2020年湖南省14个地级城市的大气污染物数据,采用GIS重心模型分析了湖南省雾霾污染的时空分布特征,并利用双变量分析法分析了其影响因素。结果显示:在年际变化上,2015—2020年湖南省各市州的雾霾污染程度总体呈波动下降,其中大部分市州的年际雾霾污染指数最高值出现在2016年。在季节变化上,由春季至秋季,湖南省雾霾污染重心向西南方向偏移;而在冬季,污染重心往西北方向偏移。综合能源消耗量、地区生产总值、交通运输和邮政业生产总值、城镇率、人口数量与湖南省雾霾污染呈显著正相关,而森林覆盖率与雾霾污染呈显著负相关。     

南京某燃煤电厂汞的排放特点及分布特征

选择南京某燃煤电厂330 MW机组，对煤、炉渣、粉煤灰、烟尘、石灰石、石膏和烟气中的汞取样测量，探讨煤中汞在燃烧过程中的变化情况，并进一步分析汞的排放特点及分布特征。指出，煤经燃煤锅炉炉内高温燃烧后，炉渣中的汞对环境影响不明显；粉煤灰、烟尘中的汞存在富集现象，且随着粒径变细，富集程度加剧；燃煤锅炉燃烧后，随石膏排放的汞占比较大，应采取相应的防治措施。