废水中铜的纳米金共振散射光谱分析

在HAc-NaAc介质中,二价铜被抗坏血酸还原成亚铜离子,并与新铜试剂生成黄色的络合物,该络合物对纳米金在580nm处的共振散射光有较强的吸收,导致其共振散射强度降低,其共振散射强度降低值ΔI与铜的浓度成线性关系,据此建立一种测定痕量铜的共振散射光谱分析方法。在选定条件下,铜含量在0.02～2.54μg/mL范围内与ΔI值呈良好的线性关系,其回归方程为ΔI580nm=87.2C+2.2,相关系数R为0.9983,检出限为0.001μg/mL,用于废水中铜的测定,结果满意。     

高温高压吸附后焦煤的孔隙结构变化特性

为研究高温高压气体吸附试验中焦煤基质膨胀后孔隙结构变化特性,首先开展了软、硬焦煤在不同吸附平衡温度(30℃、40℃、50℃)下的高温高压吸附试验,然后利用压汞法测试吸附试验前、后煤样的孔隙结构,研究了不同吸附平衡温度下的软、硬焦煤吸附性能及高温高压吸附试验对软、硬煤孔隙结构的影响.结果表明:在相同温度和压力下,硬煤瓦斯吸附量及吸附常数a均小于相应的软煤;随吸附平衡温度升高,同一煤样的瓦斯吸附量减少;高温高压吸附试验后,煤样含有大量的半封闭型的微孔和小孔,孔隙连通性变差,煤中孔隙向着更加致密的方向发展,有利于瓦斯的储存.     

基于实测的燃煤电厂汞排放特性分析与研究

选取我国6个有代表性的燃煤电厂进行现场实测,依据现场监测的汞排放浓度数据计算得出每个燃煤电厂汞的脱除率和汞平均排放因子,从而得出这6个燃煤电厂汞排放特性,为将来我国汞排放控制提供支持和依据.6个燃煤电厂的汞排放浓度为4.72～14.54μg/m3,汞脱除效率为20.89%～70.63%,汞排放因子为14.09～56.0...     

在线大气汞分析仪渗透管标定方法研究

为了实现在线大气汞分析仪的自动标定,本文选用商用的汞渗透管,自主设计了渗透恒温装置(控温精度为0.1℃),搭建了大气汞分析仪的标定模块,利用该模块建立了3种标定方法.与本实验组研发的在线大气汞分析仪联用对3种方法进行对比研究.①稀释气法:与经典的渗透管动态配气法相同,通过改变稀释气体流量(1-5 L,精度为20 mL)...     

湘江株潭长段江水(枯水期）和沉积物中汞的分布和形态

湘江株潭长段江水中(枯水期)的总汞含量为(1.881 ±1.854)μg·L-1,以颗粒态汞为主.总汞和溶解态汞最大值都出现在霞湾,霞湾-湘潭段衰减快,此后缓慢衰减一直到洞庭湖.沉积物中总汞平均含量为0.846 mg·kg-1,处于高的污染水平,沉积物总汞的最大值也出现在霞湾,达到3.268 mg·kg-1.远远超过国...     

全面建立汞污染防治体系

关于拟定一项具有全球法律约束力的汞文书政府间谈判委员会第一次会议(INC1)已于2010年6月在瑞典召开,公约谈判已经进入实质性阶段.     

Biosorption of mercury by Macrocystis pyrifera and Undaria pinnatifida: Influence of zinc, cadmium and nickel

The article investigated the adsorption of Hg(II) on Macrocystis pyrifera and Undaria pinnatifida in monometallic system and in the presence of Zn(II), Cd(II) and Ni(II).     

Mercury removals by existing pollutants control devices of four coal-fired power plants in China

The mercury removals by existing pollution control devices in four coal-fired power plants of China were carried out based on a measurement method with the aluminum matrix sorbent.     

Catalytic oxidation of gas-phase elemental mercury by nano-Fe2O3

Heterogeneous oxidation of gas-phase Hg0 by nano-Fe2O3 was investigated on a fixed bed reactor, and the e ects of oxygen concentration, bed temperature, water vapour concentration and particle size have been discussed. The results showed that Hg0 could be oxidized by active oxygen atom on the surface of nano-Fe2O3 as well as lattice oxygen in nano-Fe2O3. Among the factors that a ect Hg0 oxidation by nano-Fe2O3, bed temperature plays an important role. More than 40% of total mercury was oxidized at 300°C, however, the test temperature at 400°C could cause sintering of nano-catalyst, which led to a lower e ciency of Hg0 oxidation. The increase of oxygen concentration could promote mercury oxidation and led to higher Hg0 oxidation e ciency. No obvious mercury oxidation was detected in the pure N2 atmosphere, which indicates that oxygen is required in the gas stream for mercury oxidation. The presence of water vapour showed di erent e ects on mercury oxidation depending on its concentration. The lower content of water vapour could promote mercury oxidation, while the higher content of water vapour inhibits mercury oxidation.     

Atmospheric mercury over the marine boundary layer observed during the third China Arctic Research Expedition

TGM measurements on board ships have proved to provide valuable complementary information to measurements by a ground based monitoring network. During the third China Arctic Research Expedition (from July 11 to September 24, 2008), TGM concentrations over the marine boundary layer along the cruise path were in-situ measured using an automatic mercury vapor analyzer. Here we firstly reported the results in Japan Sea, North Western Pacific Ocean and Bering Sea, where there are rare reports. The value ranged between 0.30 and 6.02 ng/m³ with an average of (1.52 ± 0.68) ng/m³, being slightly lower than the background value of Northern Hemisphere (1.7 ng/m³). Notably TGM showed considerably spatial and temporal variation. Geographically, the average value of TGM in Bering Sea was higher than those observed in Japan Sea and North Western Pacific Ocean. In the north of Japan Sea TGM levels were found to be lower than 0.5 ng/m³ during forward cruise and displayed obviously diurnal cycle, indicating potential oxidation of gaseous mercury in the atmosphere. The pronounced episode was recorded as well. Enhanced levels of TGM were observed in the coastal regions of southern Japan Sea during backward cruise due primarily to air masses transported from the adjacent mainland reflecting the contribution from anthropogenic sources. When ship returned back and passed through Kamchatka Peninsula TGM increased by the potential contamination from volcano emissions.