燃煤电厂脱硫工艺及工艺选择要素探讨

针对我国燃煤电厂SO2排放及污染现状和目前国内外燃煤电厂普遍采用的几种典型脱硫工艺的比较,对脱硫工艺及其工艺选择的主要影响因素进行了概述。根据脱硫工艺的选择要素,从应用条件、技术、经济和环境等方面进行分析,并结合我国的实际情况,提出了燃煤电厂脱硫工艺的技术路线。     

生物质燃烧输送对青藏高原气溶胶光学辐射特性的影响研究

利用青藏高原拉萨(Lhasa)和珠峰(QOMS＿CAS)站点地基CE-318太阳光度计观测数据,研究了2012年4月2日至4月5日一次生物质燃烧输送对青藏高原气溶胶光学和辐射特性的影响;并结合卫星遥感产品以及后向轨迹模式分析了本次生物质燃烧输送的可能来源。结果表明：本次气溶胶污染期间Lhasa和QOMS＿CAS站点的主要气溶胶类型变为生物质燃烧气溶胶,气溶胶粒子的消光性增大(气溶胶光学厚度(AOD)增大,Lhasa和QOMS＿CAS站点AOD最大值分别为0.4和0.29),尺度减小(消光波长指数(EAE)>1.5),吸收性增大(吸收波长指数(AAE)>1.3),细模态粒子体积浓度增大,而细模态粒子峰值半径减小。气溶胶辐射强迫表明此次输送过程使得Lhasa和QOMS＿CAS站点的气溶胶对大气顶和地表的降温作用增强,对大气的增温作用也增强。生物质燃烧输送的可能来源为南亚的印度东北部,尼泊尔与不丹地区。     

Measurements of CO,HCN, and C2H6 Total Columns in Smoke Plumes Transported from the 2010 Russian Boreal Forest Fires to the Canadian High Arctic

In August 2010, simultaneous enhancements of aerosol optical depth and total columns of carbon monoxide (CO), hydrogen cyanide (HCN), and ethane (C₂H₆) were observed at the Polar Environment Atmospheric Research Laboratory (PEARL, 80.05°N, ?86.42°W, 0.61 km above sea level, Eureka, Nunavut, Canada). Moderate Resolution Imaging Spectroradiometer (MODIS) hot spots, Ozone Monitoring Instrument (OMI) aerosol index maps, and Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) back-trajectories were used to attribute these enhancements to an intense boreal fire event occurring in Russia. A ground-based Fourier Transform InfraRed (FTIR) spectrometer at PEARL provided vertically integrated measurements of trace gases transported in smoke plumes. We derived HCN and C₂H₆ equivalent emission ratios with respect to CO of 0.0054?±?0.0022 and 0.0108?±?0.0036, respectively, and converted them into equivalent emission factors of 0.66?±?0.27 g kg^?1 and 1.47?±?0.50 g kg^?1 (in grams of gas per kilogram of dry biomass burnt, with one-sigma uncertainties). These emission factors add new observations to the relatively sparse datasets available and can be used to improve the simulation of biomass burning fire emissions in chemical transport models. These emission factors for the boreal forest are in agreement with the mean values recently reported in a compilation study.     

全漏失钻孔预送冲洗液时间的确定

在岩心钻探施工中,全漏钻孔的预送冲洗液时间问题往往困扰着机台施工人员,为此提出了预送冲洗液的两种计算方法。     

Resin diterpenoids as tracers for biomass combustion aerosols

Diterpenoids present in atmospheric particles produced by slash burns were analyzed by capillary gas chromatography-mass spectrometry. This suite of compounds, originating in the resinous higher plants which were combusted, was comprised of reaction intermediates in the thermal transformation sequence of components such as abietic acid and dehydroabietin to retene. This sequence parallels the diagenetic alteration/decomposition processes noted in sedimentary records. Since global transport of combustion aerosols has been well documented, it is likely that the thermally-altered diterpenoids elucidated in this study can be deposited directly to sedimentary sinks.     

Recent,slow and aseismic movement of an overthrust observed in the Abel sink hole (Saint-Vallier-de-Thiey,Alpes-Maritimes,France)

Abstract

The main galleries of the Abel sink hole near Grasse (Alpes Maritimes, France) are developed along a main thrust fault. The study of speleothems clear y proves movement of this fault. The fractures indicate a north-south movement, they are not fossilised by new calcite. A large rock placed under the fault plane rotated during the movement. The soda straws fixed to the rock are curved. This allows an estimation of the movement speed. © Elsevier, Paris     

淮安一次雾霾过程的污染物变化特征及来源分析

2012年6月9-11日淮安及周边地区出现了一次严重雾霾天气,PM2.5、NOx、CO、SO2等大气污染物浓度急剧升高.本文综合利用地面空气污染监测资料、气象观测资料,分析了该次雾霾过程中污染物的变化特征和影响因素,并对污染物的来源进行了探讨.结果发现：在这次连续雾霾过程中,SO2的质量浓度都在0.049 mg/m3以下;NOx、PM2.5、CO的质量浓度与能见度呈反相关,并在整个雾霾过程中出现两个峰值,均出现在能见度低于1 000m的雾过程中;在雾霾天气过程中,中低层一直维持一个逆温层结,其中四个时次中逆温层底在975 hPa,逆温层顶在925 hPa附近,这种稳定的大气垂直结构不利于大气湍流、水汽的垂直交换以及污染物的垂直扩散,为雾霾的长时间维持创造了良好的热力条件.整个雾霾过程中,近地层始终维持偏东风向,能见度在风速下降的时候随之下降,在风速增大的时候随之增大.应用轨迹模式分析表明,有利的天气条件和大面积秸秆燃烧的结合是造成这次淮河下游连续雾霾过程发生的主要原因.     

Influence of South Asian Biomass Burning on Ozone and Aerosol Concentrations Over the Tibetan Plateau

In this work, the influence of South Asian biomass burning emissions on O₃ and PM_2.5 concentrations over the Tibetan Plateau (TP) is investigated by using the regional climate chemistry transport model WRF-Chem. The simulation is validated by comparing meteorological fields and pollutant concentrations against in situ observations and gridded datasets, providing a clear perspective on the spatiotemporal variations of O₃ and PM_2.5 concentrations across the Indian subcontinent, including the Tibetan Plateau. Further sensitivity simulations and analyses show that emissions from South Asian biomass burning mainly affect local O₃ concentrations. For example, contribution ratios were up to 20% in the Indo-Gangetic Plain during the pre-monsoon season but below 1% over the TP throughout the year 2016. In contrast, South Asian biomass burning emissions contributed more than 60% of PM_2.5 concentration over the TP during the pre-monsoon season via significant contribution of primary PM_2.5 components (black carbon and organic carbon) in western India that were lofted to the TP by westerly winds. Therefore, it is suggested that cutting emissions from South Asian biomass burning is necessary to alleviate aerosol pollution over the TP, especially during the pre-monsoon season.     

Research on the February 18, 1996 earthquake in the caves of Saint-Paul-de-Fenouillet area, (eastern Pyrenees,France)

Abstract

Eight caves have been investigated near Saint-Paul- de-Fenouillet after the earthquake of 5.2 magnitude of February 1996 which occurred in the eastern Pyrenees (France) and caused moderate damage at the ground surface. The earthquake has been associated with the movement of an E-W fault. The caves had not been visited since the earthquake. Some damage, mainly collapses of soda straws and small rocks, could be attributed to this earthquake. The most interesting cave in the epicentral area is the Paradet cave which is situated on a recently activated fault plane. In this cave, soda straw falls could be attributed to the earthquake, but other more ancient damage was also observed. Analysis of the azimuth of fallen speleothems, which are natural pendulums, may indicate the directions, and an estimation of their mechanical properties gives the threshold of the seismic ground motion amplitude responsible for their collapse, thus supplying information to calibrate damage due to past earthquakes. A statistical study indicates that the main direction of the collapsed soda straws is E–W. Numerical simulations confirm that soda straws are relatively strong objects that may break under certain conditions during earthquakes. © Elsevier, Paris     

Airborne measurements of savanna fire emissions and the regional distributio of pyrogenic pollutants over Western Africa

We measured CO₂, CO, CH₄, H₂, and NO₂ in air masses polluted by savanna fires over Côte d'Ivoire, western Africa. Elevated concentrations of these trace gases were found in fire plumes and also in extensive haze layers. Trace gas mixing ratios ranged as high as 605 ppmv for CO₂, 14.8 ppmv for CO, 2.7 ppmv for CH₄, 4.2 ppmv for H₂, and 25 ppbv for NO₂. We compare our emission ratios to those obtained in previous field and laboratory studies. The emission ratios, expressed as an average and as a range or as an average only, were: dCO/dCO₂ 5.3×10^–2 (3–18×10^–2); dCH₄/dCO 5.3×10^–2; dH₂/dCO 2.4×10^–1 and dNO₂/dCO₂ 1.8×10^–4 (1.5–2.2×10^–4). The values found match those found during similar measurements, though our results point to rather vigorous burning in the savanna of western Africa.