典型化工废渣污染土壤中汞的空间分布规律研究

为阐明氯碱厂废渣堆积遗留场地中汞的空间分布规律,在某典型场地设置313个表层（0.5 m）、79个深层（0.5～13.5 m）土壤采样点位及6个地下水采样点位,分析所有土壤样品的总汞浓度、表层土壤的理化性质及地下水总汞浓度.结果显示：（1）该场地土壤汞污染严重,313个表层土壤样点汞检出浓度为0.002～579.14 mg·kg^-1,平均为8.43 mg·kg^-1,高于《土壤环境质量农用地土壤污染风险管控标准（试行）》中的风险管控值(6 mg·kg^-1).反距离权重法（IDW）及自然邻域法（NNI）对该场地的汞水平浓度分布的插值更为准确.（2）79个深层点位土壤垂向检测结果显示,土壤上层区域（0.5、1.5、2.5 m）汞污染浓度更高,3个深度层的汞浓度平均值分别为7.3、5.5、3.1 mg·kg^-1,2.5 m以下7个深度层的汞浓度平均值仅为（1.02±0.15）mg·kg^-1;汞垂向富集因子为0.4～32,大多数（66%）采样点位汞的富集因子（EF）随着土壤深度增加显著下...     

Comparisons of particulate-bound mercury (PBM) compositions in soil and vegetation at a traffic site

This investigation analyzes the particulate-bound mercury (PBM) compositions in soil and vegetation at a traffic sampling site in Taichung, Taiwan, during a sampling period from October to December, 2015. A direct mercury analyzer (DMA-80) was used to measure the particulate-bound mercury (PBM). A T-test was conducted to determine the mean differences between the PBM composition in soil and that in vegetation at the site. The results indicate that 1) the mean particulate-bound mercury compositions in soil and vegetation were the lowest in November, when the (mean OR average) wind speed was the highest (4.1 m/s); 2) Particulate-bound mercury compositions (PBM) in both soil and vegetation correlated weakly with temperature, humidity and wind speed; 3) T-test statistical results denoted that the PBM compositions did not significantly differ between soil and vegetation in the three-month sampling period.     

鸭绿江口汞的污染状况及其防治对策

本文以对鸭绿江口水中、沉积物中以及１６种鱼鱼体中Ｈｇ含量的实测结果,阐明了鸭绿江口Ｈｇ的污染状况,在找出该江口Ｈｇ的主要污染源的基础之上,提出了三项Ｈｇ的污染防治对策,以其中的Ｈ２Ｓ除Ｈｇ的实验结果,阐述了该法技术经济上的可行性。     

宝鸡市街尘中As和Hg含量及其环境风险评价

利用原子荧光分光光度计对宝鸡市38个街尘样品进行分析测试,以研究街尘中As和Hg含量的水平及其空间分布特征,并与中国土壤及其他城市街尘中的含量进行对比.结果表明:宝鸡市街尘中w(As)为8.985～42.822 　μg/g,平均值为19.764 　μg/g,约为中国土壤元素背景值(11.2 　μg/g)的1.8倍,是其他城市街尘w(As)均值的2～4倍;w(Hg)为0.483～2.318 　μg/g,平均值为1.112 μg/g,约为中国土壤元素背景值(0.065 　μg/g)的17.1倍,为其他城市街尘w(Hg)均值的10倍.工业区街尘中w(As)相对较高,商业区街尘中w(Hg)相对较高.利用污染指数法和地积累指数法对宝鸡市街尘中As和Hg的环境风险进行评价,结果表明:宝鸡市街尘中As的污染指数平均值为1.765,地积累指数平均值为0.144,存在轻度的污染;Hg的污染指数平均值为17.106,地积累指数平均值为3.425,呈现出偏重污染.      

湘黔汞矿区土壤汞的化学形态及污染特征

以湘黔汞矿带内典型矿区土壤为对象,基于BCR三步法和氢化发生-等离子体发射光谱技术,研究了湘黔汞矿区土壤中汞的形态含量及污染特征.结果表明,矿区土壤中汞以残渣态为主,其次为有机-硫化态,酸交换态和铁锰氧化态所占比例较少,各形态汞的分配系数依次为：残渣态(85.77%)>>有机-硫化态(12.44%)>>Fe-Mn氧化态(0.93%)≈酸交换态(0.86%);土壤中各形态汞含量与砂粒含量正相关,与粘粒含量负相关,并随土壤pH升高而增加;各形态汞含量存在明显的空间分异,垂直空间上体现为表层土壤中的含量高于亚表层土壤,水平空间上表现为随着与污染源距离的增加而含量急剧降低,并因土地利用类型不同、区域不同而差异明显.人类活动引起的外源输入性汞污染对矿区土壤中汞的环境毒性和污染特征产生了重大影响.     

节肢动物体内的总汞和甲基汞含量研究

分析了汞污染区河流沿岸草本植物及节肢动物样品中的汞含量.结果表明,节肢动物飞蝗、中华蚱蜢总汞含量分别为0 .032～0 .402 mg·kg^-1、0 .023～0 .362 mg·kg^-1,高于非污染区1个数量级.飞蝗、中华蚱蜢甲基汞含量分别为0 .003～0 .031mg·kg^-1、0 .004～0 .015 mg·kg^-1,占总汞比例分别为3 .5%～49 .7%和2 .0%～44 .4%.飞蝗、中华蚱蜢体内（一级消费者）汞含量低于其食物草本植物,与未受污染地区不同;螳螂体内（二级消费者）汞明显累积.飞蝗体内总汞含量随着个体长度增长呈下降的趋势,在中华蚱蜢体内则先增长后下降,甲基汞随着个体长度增长呈上升趋势;节肢动物个体不同部位中汞含量明显不同,腹>胸>头.节肢动物体内汞和甲基汞可能导致野生鸟类、家禽、两栖类生态风险.     

北京市典型地区大气可吸入颗粒物中汞的浓度水平和粒径分布

在北京市近郊和远郊区采集大气中可吸入颗粒物样品,分析其汞的浓度水平.结果表明,近郊大气可吸入颗粒物中汞的浓度高于远郊区,分别为1.28±1.30ng·m-3和0.79±0.68ng·m-3,而且冬、春两季的浓度明显高于夏、秋两季.可吸入颗粒物中的汞主要分布在细粒子中,且细粒子富集汞的能力较粗粒子强.     

不同腐殖酸物质对土壤中汞的固定作用及植物吸收的影响

通过盆栽试验研究了不同腐殖酸物质对土壤有机结合态汞、全汞含量及土壤汞生物有效性的影响.结果表明,不同供试腐殖酸物质可以显著增加土壤中有机结合态汞和残留在土壤中汞的含量,降低土壤中汞的挥发量,从而有效降低土壤汞的生物有效性.与加入HgCl2但不施加腐殖酸物质的对照CK2相比,添加腐殖酸钠、提纯后的煤基腐殖酸、土壤腐殖酸、氨化风化煤、风化煤、褐煤、泥炭的处理中油菜对土壤中汞的吸收量分别降低了73.62%、71.11%、63.39%、40.05%、33.61%、22.26%、5.66%.     

ZnCl2法污泥含炭吸附剂对模拟烟气中气态汞的吸附

采用改进的ZnCl2学活化法制备污泥含炭吸附剂,利用EDS以及氮吸附等多种测试手段对所制得的污泥含炭吸附剂进行表征,并利用其处理模拟烟气汞污染物,实验结果表明,污泥含炭吸附剂对Hg^0吸附包括物理吸附作用和化学吸附作用,以物理吸附作用为主;随着Hg^0入口浓度的提高,污泥含炭吸附剂的Hg^0饱和吸附容量增大;随着吸附反应温度的升高污泥含炭吸附对Hg^0的吸附作用减弱;在吸附反应温度125℃,Hg^0入口浓度60．4μg／m3污泥含炭吸附剂和选定的活性炭对Hg^0吸附容量分别为81．2gg／g和53．8μg／g,污泥含炭吸附剂对Hg^0吸附作用好于选定的活性炭。     

Atmospheric mercury concentrations and speciation measured from 2004 to 2007 in Reno, Nevada, USA

Atmospheric elemental, reactive and particulate mercury (Hg) concentrations were measured north of downtown Reno, Nevada, USA from November 2004 to November 2007. Three-year mean and median concentrations for gaseous elemental Hg (Hg⁰) were 1.6 and 1.5 ng m⁻³ (respectively), similar to global mean Hg⁰ concentrations. The three-year mean reactive gaseous Hg (RGM) concentration (26 pg m⁻³) was higher than values reported for rural sites across the western United States. Well defined seasonal and daily patterns in Hg⁰ and RGM concentrations were observed, with the highest Hg⁰ concentrations measured in winter and early morning, and RGM concentrations being greatest in the summer and mid-afternoon. Elevated Hg⁰ concentrations in winter were associated with periods of cold, stagnant air; while a regularly observed early morning increase in concentration was due to local source and surface emissions. The observed afternoon increase and high summer values of RGM can be explained by in situ oxidation of gaseous Hg⁰ or mixing of RGM derived from the free troposphere to the surface. Because both of these processes are correlated with the same environmental conditions it is difficult to assess their overall contribution to the observed trends.