Spatial distribution of mercury in topsoil from five regions of China

The concentrations and distributions of mercury (Hg) in topsoil from four provinces and one municipality in China were investigated. A total of 1,254 samples were collected and analyzed. The average concentrations of Hg were 0.064 mg kg^?1 for Liaoning Province, 0.100 mg kg^?1 for Jiangsu Province, 0.110 mg kg^?1 for Zhejiang Province, 0.154 mg kg^?1 for Sichuan Province, and 0.098 mg kg^?1 for Chongqing Municipality. Although differences were found among the ranges of Hg concentrations, the average values for each region were similar with other published data. The concentrations of Hg in topsoil varied largely upon the sampling locations. More than 80 % of the soil samples from Liaoning Province, Jiangsu Province, Zhejiang Province, and Chongqing Municipality, were ranked Grade I by the China Environmental Quality Standard for Soils, which can be considered as not contaminated by Hg. The concentrations of Hg in 0.3–0.4 % of soils collected from Jiangsu Province, Zhejiang Province and Chongqing Municipality exceeded the limitation for Grade III, indicating the contamination of Hg in these sites. The sources and potential risks of Hg in these sites should be brought to attention and further investigated.     

丹寨汞金矿床卤素元素与古油藏关系探讨

丹寨汞金矿床是与古油藏共生的金属矿床 ,产在古油藏的边缘 ,矿区内发育大量的油气演化产物沥青、含烃有机包裹体等有机质 ,可见该矿床与古油藏有密切的地质关系。对矿区内卤素元素地球化学特征的研究结果表明 ,矿区内溴、碘的富集程度远比氟、氯高 ,这与古油藏油田卤水的形成演化有关。而且 ,油田卤水是该矿床成矿热液的主要来源。     

岩矿样品X射线荧光分析中多元素体系理论α系数的计算和应用

本文提出了岩矿样品X射线荧光分析中多元素体系的理论α系数的一种计算方法。假设试样由n个组分组成,其各组分平均含量为Cl(Cl=1,2,3,…k,……n),然后,假设某一组分的含量Cl相对于平均含量Cl有一微小变化量ΔC,并使每个组分相应变化一次,用基本参数法方程计算理论X射线相对强度;再按一定的数学模式计算相应的基本α系数,混合α系数和修正α系数。以实例计算了用于地质样品分析的各种理论α系数,应用于实际分析中结果令人满意。     

北京西北城区与清洁对照点夏季大气PM10的微观特征及粒度分布

应用高分辨率场发射扫描电镜(FESEM)和图像分析技术研究了北京西北城区和清洁对照点非取暖期(2001年夏季)大气单个颗粒物的形貌特征以及PM₁₀和PM_2.5的数量-粒度和体积-粒度分布.研究表明,烟尘集合体在2个采样点都普遍存在,具有区域性污染的特征;不规则状矿物颗粒物多见于市区PM₁₀样品中,而长条状石膏颗粒多出现在清洁对照点颗粒物样品中;在清洁对照点还观察到了生物质颗粒.PM₁₀的数量-粒度分布呈双峰分布,主峰为0.2～0.5μm,次峰为在1～2.5μm但PM₁₀的体积-粒度分布呈单峰分布,在1～2.5μm粒度范围内.综合分析得出,虽然粗颗粒,主要是矿物颗粒,在数量上对PM₁₀贡献很小,但是对总体积,因此对总质量的贡献可能很大但在PM_2.5中,烟尘集合体在数量和体积上均占优势.     

兰州市沙尘天气及其对空气质量的影响

利用1971~2000年和2001~2004年兰州市观测站资料,分析了兰州市沙尘天气的气候特征和2001~2004年沙尘天气特点及产生原因。研究表明,兰州市区的沙尘天气30年来呈明显减少趋势,但近几年明显增多。兰州市的沙尘天气以浮尘、扬沙天气为主。沙尘天气春季(3~5月)最多,4月占全年天数的24.2%。利用2002~2004年主要污染物浓度资料和2006年4月5~15日逐日的PM10浓度资料研究了沙尘天气对兰州市区主要污染物浓度的影响,结果表明,沙尘天气发生时,伴随的大风等气象条件有利于SO2和NO2的扩散,而强沙尘天气容易导致PM10日均浓度迅速升高。在分析的一次强沙尘天气个例中,兰州市区PM10日均浓度陡然升高到1.86 mg/m3,是前一日的10.4倍。     

6种矿质元素对青菜中硝酸盐含量的影响

通过盆栽试验 ,研究了B、K、Mn、Mg、Zn、Co对青菜中硝酸盐含量的影响。结果表明 :增施硼酸钠后第 2 0天 ,青菜硝酸盐含量比对照降低 1 4 84%～ 1 9 56 % ;增施K、Mn、Mg、Zn、Co也能降低青菜硝酸盐含量。每盆增施0 1gZnSO4 后第 1 0天 ,青菜中硝酸盐含量比对照减少 1 8 96 % ,每盆增施 0 1gK2 SO4 后第 2 0天 ,青菜中硝酸盐含量比对照减少 2 1 42 % ;矿质元素的施用量对青菜硝酸盐含量影响较大。     

长光路FTIR研究HCFC22大气光化学反应

用长光路ＦＴＩＲ技术模拟研究氟里昂替代物ＨＣＦＣ２２（ＣＨＣ１Ｆ２）在对流层中的光化学反应，氯原子作反应的引发剂．ＨＣＦＣ２２在对流层中的主要含氟光解产物为ＣＯＦ２，讨论了有关反应机理，并对ＨＣＦＣ２２的环境影响和工业应用前景进行了评价。     

磷酸三苯酯对斑马鱼早期生命阶段的神经毒性研究

磷酸三苯酯(triphenyl phosphate,TPP)作为多溴联苯醚类阻燃剂的替代产品,是一类生产和需求量均相当高的有机磷酸酯类阻燃剂,目前已在多种环境介质以及生物体内均有不同程度检出。由于结构和有机磷农药具有相似性,其对生物的神经毒性值得关注。本研究以斑马鱼为实验动物,研究了TPP(5~625%g·L-1)的胚胎发育毒性和行为毒性,并通过检测乙酰胆碱酯酶活性以及神经系统相关基因的转录水平,探讨其可能的毒性机制。研究发现,TPP可导致斑马鱼胚胎孵化时间延长,体长变短,心率变慢。同时,TPP暴露也可以影响斑马鱼幼鱼在持续光照和明暗周期刺激下的游泳行为,表现为低浓度增加而高浓度降低其游泳速度。而TPP暴露后幼鱼乙酰胆碱酯酶活性以及神经发育相关基因转录水平的变化可能是导致其行为毒性的原因。虽然实验中所设定的暴露浓度高于环境中一般浓度,但TPP在短期暴露中所表现出的胚胎和神经发育毒性表明TPP对于水生生物可能存在一定风险,需要进一步研究加以确认。     

Variations and sources of ambient formaldehyde for the 2008 Beijing Olympic games

As the host city of the 2008 Olympic games, Beijing implemented a series of air pollution control measures before and during the Olympic games. Ambient formaldehyde (HCHO) concentrations were measured using a fluorometric instrument based on a diffusion scrubber and the Hantzsch reaction; hydrocarbons were simultaneously measured using gas chromatography–mass spectrometry (GC–MS). Meteorological parameters, CO, O₃, and NO₂ concentrations were measured by standard commercial instrumentation. In four separate periods: (a) before the vehicle plate number control (3–19 July); (b) during the Olympic Games (8–24 August); (c) during the Paralympic Games (6–17 September) and (d) after the vehicle control was ceased (21–28 September), the average HCHO mixing ratios were 7.31 ± 2.67 ppbv, 5.54 ± 2.41 ppbv, 8.72 ± 2.48 ppbv, and 6.42 ± 2.79 ppbv, while the total non-methane hydrocarbons (NMHCs) measured were 30.41 ± 18.08 ppbv, 18.12 ± 9.38 ppbv, 30.50 ± 13.37 ppbv, and 33.33 ± 15.85 ppbv, respectively. Both HCHO and NMHC levels were the lowest during the Olympic games, and increased again during the Paralympic games even with the same vehicle control measures operative. Similar diurnal HCHO and O₃ patterns indicated that photo-oxidation of NMHCs may be the major source of HCHO. The diurnal profile of total NMHCs was very similar to that of NO₂ and CO: morning and evening peaks appeared in rush hours, indicating even after strict vehicle control, automobile emission may still be the dominant source of the HCHO precursors. The contributions of HCHO, alkanes, alkenes, and aromatics to OH loss rates were also calculated. HCHO contributed 22 ± 3% to the total VOCs and 24 ± 1% to the total OH loss rate. HCHO was not only important in term of abundance, but also important in chemical reactivity in the air.     

电化学氧化法处理模拟黄连素制药废水的研究

以RuO2/Ti为阳极,研究了电化学氧化法对黄连素制药废水的处理效果.通过比较在KCI与K2SO42种支持电解质体系中的处理效果,同时考察了电流强度、初始pH、电解质浓度和电极间距等因素对废水中黄连素及COD去除率的影响,明确了电化学原位生成活性氯是黄连素降解的主要原因;确定了电流强度、pH、电解质浓度和电极间距等最优...