Flow analysis of PCDD/Fs for Tarragona Province, Spain

The present study was intended to establish an inventory of PCDD/F emissions in Tarragona Province (Catalonia, NE Spain), as a preliminary phase in the development of a flow analysis of PCDD/Fs in this Province. In 1999, global PCDD/F emissions reached a value of 2.24 g I-TEQ/y, which means a density of 3.8 micrograms I-TEQ/inhabitant/y. The low amount of PCDD/Fs emitted to air by the only municipal solid waste incinerator in the Province (approximately 0.04% of the total) has been one of the most notable results. As a reflection of uncertainties in the estimates for individual sources, the 90th percentiles of PCDD/F releases for 1999 ranged up to 4.1 g I-TEQ/y.     

天津市高架点源对城区空气质量影响分析

从典型高架点源到城市众多高架源的污染进行综合分析，阐述了高架点源的污染分布特征和对城市空气质量的影响，高架点源对天津市污染物排放贡献率为45％，但对城市空气质量影响为12％。     

国家标准GB／T3840—91中城市大气污染物总量控制A—P值法的应用

本文叙述了在大气总悬浮微粒物实行总量控制时使用GB/T384-91中A-P值方法的经验,给出了一些计算公式及参数,同时还介绍了使用上述国家标准时对求算允许排放总量的主要参数土地面积进行人口订正的经验公式和确定经验系数的方法.     

提高柴油质量减少汽车排气污染

柴油机车应用于道路运输具有许多优点，但环境保护要求减少排气污染、颗粒排放污染至关重要，为此，强化柴油燃料规格是其主要的驱动力。本文介绍了美国，西欧和亚太地区柴油质量现状和趋势，分析了我国柴油燃料质量及其改进意见。     

北京市轻型汽车尾气排放检测结果分析

对北京市566辆在用轻型车排放尾气进行了BASM检测，对不同厂牌的化油器车、化油器改造车和电喷车排放的HC、CO和NO平均浓度进行了比较，结果表明，化油器改造车3种污染物平均浓度比化油器车低50％左右，电喷车3种污染物平均浓度可比化油器车低80％左右。同时对几种车型的劣化规律进行了分析，发现化油器车的劣化关系离散性大，而另外两种技术的车辆的劣化关系呈收敛性，说明化油器车的污染物排放和保养关系密切，电喷车劣化规律明显优于化油器车和化油器改造车。实验结果为I／M实施提供了科学依据。     

中国农业土壤N2O排放量估算

采用针对农业土壤痕量气体排放估算开发的、基于N2O的产生、传输和消耗机理的反硝化分解模型(DNDC模型),在建立的有关中国气候、农业土壤和农业生产的分县数据库基础上,估计了我国目前农业土壤N2O的排放量,并分析了气候变化和农业耕作措施对全国N2O排放的影响.结果表明,中国农田土壤的N2O排放总量为0.31(0.18-0.44)Tg(N)·a-1,化肥使用量的变化对N2O排放量的影响最大.     

全球N_2O年释放总量及各类源相对贡献率初步分析

根据国际上最近确定的全球N2 O各释放源及其释放量估算值 ,推算了全球N2 O年释放总量及各类源的相对贡献率。得出全球N2 O年释放总量约 1 4 .7TgN2 O -N ,其中自然源和人为源分别占 57%和 4 3 %。年释放总量中N的生物地球化学过程约贡献92 %、非生物作用过程仅贡献 8% ;与土壤有关的释放源约贡献 70 %、农业土壤贡献2 0 %。控制土壤尤其是农业土壤和热带森林土壤的N2 O释放量是控制全球大气N2 O浓度上升的关键     

绿色机动车—燃料电池汽车

简要叙述了燃料电池汽车的技术特点，主要有：能量转化效率高，ＣＯ２排放量比内燃机汽车低，基本不产生有毒气体，不要充电。在此基础上较详细地介绍了世界各国的燃料电池汽车研究现状，并针对上海市机动车污染严重的现状，提出了发展燃料电池汽车及其相关产业的建议。     

The role of CH4 and N2O emission reductions in the cost-effective control of the greenhouse gas emissions from Finland

The reduction of carbon dioxide (CO₂) emissions may be quite expensive and it is necessary to consider reduction measures for other anthropogenic greenhouse gases, such as methane (CH₄) and nitrous oxide (N₂O) as well. Their contribution to the total GHG emission from Finland is about 15–20%. In Finland most of the CH₄ emissions are due to waste management, agriculture and burning processes. N₂O emissions originate from burning processes, agriculture, industry and atmospheric deposition of nitrogen. The cost-effective reduction of the Finnish GHG emissions has been studied with the EFOM-ENV model, which is a quasi-dynamic linear energy system optimisation model. The target function to be minimised is the total discounted cost for the modelled system. In this study the model has been expanded to cover all well-known anthropogenic CO₂, CH₄ and N₂O sources and reduction measures. The results indicate it is economic to reduce the emissions of CO₂, CH₄ and N₂O in Finland. It is profitable to exploit the economic reduction potential of CH₄ and N₂O, because then the abatement of CO₂ emissions does not need to be as extensive as when the reduction is aimed only at CO₂ emissions. The inclusion of CH₄ and N₂O decreases the annual reduction costs about 20% in the year 2010.     

Origins of black carbon from anthropogenic emissions and open biomass burning transported to Xishuangbanna, Southwest China

Black carbon (BC) has importance regarding aerosol composition, radiative balance, and human exposure. This study adopted a backward-trajectory approach to quantify the origins of BC from anthropogenic emissions ($\mathrm{B}{\mathrm{C}}_{\text{An}}$) and open biomass burning ($\mathrm{B}{\mathrm{C}}_{\text{BB}}$) transported to Xishuangbanna in 2017. Haze months, between haze and clean months, and clean months in Xishuangbanna were defined according to daily PM_2.5 concentrations of >75, 35–75, and <35 µg/m³, respectively. Results showed that the transport efficiency density (TED) of BC transported to Xishuangbanna was controlled by the prevailing winds in different seasons. The yearly contributions to the effective emission intensity of $\mathrm{B}{\mathrm{C}}_{\text{An}}$ and $\mathrm{B}{\mathrm{C}}_{\text{BB}}$ transported to Xishuangbanna were 52% and 48%, respectively. However, when haze occurred in Xishuangbanna, the average $\mathrm{B}{\mathrm{C}}_{\text{An}}$ and $\mathrm{B}{\mathrm{C}}_{\text{BB}}$ contributions were 23% and 77%, respectively. This suggests that open biomass burning (BB) becomes the dominant source in haze months. Myanmar, India, and Laos were the dominant source regions of BC transported to Xishuangbanna during haze months, accounting for 59%, 18%, and 13% of the total, respectively. Furthermore, India was identified as the most important source regions of $\mathrm{B}{\mathrm{C}}_{\text{An}}$ transported to Xishuangbanna in haze months, accounting for 14%. The two countries making the greatest contributions to $\mathrm{B}{\mathrm{C}}_{\text{BB}}$ transported to Xishuangbanna were Myanmar and Laos in haze months, accounting for 55% and 13%, respectively. BC emissions from Xishuangbanna had minimal effects on the results of the present study. It is suggested that open BB in Myanmar and Laos, and anthropogenic emissions in India were responsible for poor air quality in Xishuangbanna.