模拟酸雨对石刻的腐蚀

采用pH值分别为5.6,4.5和3.0的人工模拟酸雨,在实验室条件下对具有相同成分的石材进行降雨侵蚀实验,测定了不同pH值下的腐蚀速率.同时,运用XRD和SEM分析酸雨腐蚀的规律.结果表明:酸雨侵蚀首先发生在颗粒间隙处;pH值愈低,腐蚀愈严重;酸雨腐蚀后,石材表面碳酸钙流失严重,其它成分相对富集在表面,而且改变了其原来的形貌.     

利用MOBILE 6.2模型预测LPG出租车排放因子

针对MOBILE6．2预测天然气汽车排放因子的功能,分析了其在预测液化石油气（LPG）轻型汽车上的可行性。并根据LPG出租车汽车排放总量分析系统（VMAS）测试结果,得到所需参数,预测了实验车队的排放因子,与实测值的误差≤10％,表明MOBILE6．2预测LPG轻型汽车排放因子具有良好的适用性。     

辽宁省电力行业CO2减排措施的研究

通过采用调查与统计年鉴数据相结合的方法,计算出辽宁省电力行业CO2排放量,结果表明,辽宁省电力行业的CO2排放量为1．52亿t,占辽宁省CO2总排放量的43．80％。其中,大连电力行业的CO2排放量居辽宁省电力行业第1位,铁岭、抚顺和葫芦岛分别排在2、3、4位。并提出削减辽宁省电力行业CO2排放量的措施     

CFB锅炉多点排放二氧化硫污染预测

循环流化床锅炉（CFB）多点排放时,直接测量分析对环境的影响较为困难。为了确定其中SO2对环境的影响,通过对鼢在CFB锅炉生产过程中的生成、转化和大气中的扩散分析,建立了多点排放的SO2污染预测正态分布模型。模型结果表明,多点排放时大气SO2的浓度分布仍满足正态分布特征,并较好地反映了最大落地浓度及位置,这对于依据区域大气SO2总量控制,确保和提高设备与工艺系统的清洁生产能力提供了可行依据。     

Estimation of the impact of oil palm plantation establishment on greenhouse gas balance

Estimates of emissions indicate that if tropical grassland is rehabilitated by oil palm plantations, carbon fixation in plantation biomass and soil organic matter not only neutralises emissions caused by grassland conversion, but also results in the net removal of about 135 Mg carbon dioxide per hectare from the atmosphere. In contrast, the emission from forest conversion clearly exceeds the potential carbon fixation of oil palm plantings. Forest conversion on mineral soils to promote continued oil palm mono cropping causes a net release of approximately 650 Mg carbon dioxide equivalents per hectare, while the emission from peat forest conversion is even higher due to the decomposition of drained peat and the resulting emission of carbon oxide and nitrous oxide. The conversion of one hectare of forest on peat releases over 1,300 Mg carbon dioxide equivalents during the first 25-year cycle of oil palm growth. Depending on the peat depth, continuous decomposition augments the emission with each additional cycle at a magnitude of 800 Mg carbon dioxide equivalents per hectare. The creation of ‘flexibility mechanisms’ such as the clean development mechanism and emission trading in the Kyoto Protocol could incorporate plantations as carbon sinks in the effort to meet emission targets. Thus, for the oil palm industry, grassland rehabilitation is an option to preserve natural forest, avoid emissions and, if the sequestered carbon becomes tradable, an opportunity to generate additional revenue. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue.     

Emission modelling and validation of VOCs' source strengths in air-conditioned office premises

An emission model for indoor volatile organic compounds (VOCs) based on mass balance considerations has been presented and validated under steady state conditions. Comparison were made for the measured and predicted concentrations of 37 selected VOCs and TVOC through a case intervention study on the filters of the ventilation system in a new commercial air-conditioned office building. The intervention involved replacing media filters with electronic and carbon filtration. TVOC and 37 compounds selected for their health and comfort impact, representation of major chemical classes that occur in indoor air and their utility as markers of pollution sources were studied. The concentration levels predicted by the model were compared with actual measurements. Twenty-five target compounds and the TVOC were adequately described by the model where the measured concentrations were in agreement with the predicted concentrations. Modeling of the remaining 12 compounds was found to be affected by the emission rates that were occupant related.     

Characterisation and determination of profiles of polycyclic aromatic hydrocarbons in a traffic tunnel in Gothenburg, Sweden

The concentrations of semi-volatile polycyclic aromatic hydrocarbons (PAHs), hydrocarbons (HCs), particulate matter (PM 1, 2.5 and 10 μm) and total suspended particles (TSPs) were measured in a traffic tunnel in Gothenburg, Sweden. Emission factors (EFs) were also calculated. These variables are assumed to provide good estimates of average vehicle emissions, since all types of vehicle, using all types of fuel, pass through this tunnel. It was shown that the majority of particle-associated PAHs were found on particles with an aerodynamic diameter of <1 μm. The concentrations of PAHs were one order higher in magnitude in air samples from the tunnel than in air samples at two urban locations. However, the PAH profiles of air samples from the tunnel and the urban sites were similar. This was demonstrated using principal component analysis (PCA). Finally, and notably, there was no significant change in the total emissions when the proportion of heavy-duty vehicles (HDVs) increased from 8% to 24%. Previously, diesel vehicles had been found to release larger quantities of PAHs and related substances. Advances in fuel quality, and HDV motor and exhaust system design during the last decade may have contributed to this promising result. However, it was shown, using partial least squares regression to latent structures (PLS), that some of the parameters measured displayed correlations with the proportions of HDVs and light-duty vehicles (LDVs). Concentrations of total HCs, TSPs, dibenzothiopene, phenantrene, anthracene and monomethyl-derivatives of phenantrene and anthracene were all correlated to the proportion of HDVs. The concentrations of naphthalene, some mono- and dimethylnaphthalenes and most large PAHs (with 5–7 fused rings) were correlated to the proportion of LDVs.     

Mesoscale modeling of wintertime particulate matter episodes in eastern Washington, USA

The Spokane, Washington area is classified as a non-attainment area for the 24-h PM₁₀ standard due to a history of high particulate matter concentrations. A Eulerian regional air quality model (CALMET/CALGRID) has been used to characterize the emission, transport and dispersion of PM₁₀ and PM_2.5 in Spokane. Observations from a residential site (Rockwood, RW) and an industrial site (Crown Zellerbach, CZ), spanning July 1994–August 1996 were used to evaluate the current emission inventory. Two major tasks were devised to conduct the objectives of this investigation. First, a simple and efficient urban dispersion model (WYNDValley) was used to simulate important episodes characterized by the highest PM₁₀ and PM_2.5 concentrations. The selected episodes included four days with wet conditions for which no roads would have been emitting and seven days with dry conditions for which roads would emit. In the second step, a single road-emitting event was selected from the previous predicted results for further analysis using the Eulerian regional air quality model to examine the emission inventory. The urban and regional models predicted the observed concentration distributions reasonably well for the source emissions inventoried in Spokane. The mass concentrations of PM₁₀ were well predicted for the roads emitting case examined by both models indicating that the emission inventory based primarily upon area sources including roads is reasonably well characterized, at least at the RW site. The area sources around CZ are less well characterized, so that the PM₁₀ concentrations are underpredicted at CZ. The models appear unable to reach an equilibrium mass balance status at the beginning of the simulation, and the urban model seems unable to properly resolve the nocturnal boundary layer.     

Flattening the carbon extraction path in unilateral cost-effective action

Internalizing the global negative externality of carbon emissions requires the flattening of the extraction path of world fossil energy resources (=world carbon emissions). We consider governments with sign-unconstrained emission taxes at their disposal and seeking to prevent world emissions from exceeding some binding aggregate emission ceiling in the medium term. Such a ceiling policy can be carried out either in full cooperation or by a sub-global climate coalition. Unilateral action has to cope with carbon leakage and high costs, which makes a strong case for choosing a policy that implements the ceiling in a cost-effective way. In a two-country, two-period general equilibrium model with a non-renewable fossil-energy resource, we characterize the unilateral cost-effective ceiling policy and compare it with its fully cooperative counterpart. We show that with full cooperation there exists a cost-effective ceiling policy in which only first-period emissions are taxed at a rate that is uniform across countries. In contrast, the cost-effective ceiling policy of a sub-global climate coalition is characterized by emission regulation in both periods. The share of the total stock of energy resources owned by the sub-global climate coalition turns out to be a decisive determinant of the sign and magnitude of unilateral cost-effective taxes.     

长江经济带碳排放现状及未来碳减排

长江经济带是我国"三大支撑带"之一,其碳减排目标实现对我国生态文明建设具有重要意义。采用2005~2013年长江经济带(含9省2市)的能源消耗与经济社会数据,通过数理统计,得出各地历年碳排放量、人均碳排放、能源强度、产业结构多元水平的具体数值及变化率,结合运用弹性计算和矩阵分类法,发现长江经济带碳排放存在空间与结构差异。研究结果显示:(1)长江经济带碳排放及增长率、人均碳排放及增长率、能源强度都高于全国平均水平,能源强度下降率低于全国平均水平;把长江经济带分为东中西三段区域,碳排放总量、人均碳排放及能源强度下降率梯度下降,碳排放增长率、人均碳排放增长率、能源强度梯度上升。(2)工业化开始越早、重工业化主导向生产性服务业主导转变越快、越充分地区,经济低碳化水平越高;通过提升产业结构多元化速度有利于碳减排。(3)长江经济带各地实现碳减排措施应有不同,东段地区应着重降低人均碳排放,中西段地区应着重于降低能源强度。(4)未来碳减排应兼顾公平与效率,各地区碳减排目标分配应结合各地支付能力、碳汇能力、生产效率、能源结构等因素来安排。