Photocatalytic removal of nitrogen oxides via titanium dioxide

We studied the removal of nitrogen oxides pollutants via TiO₂ Degussa P25 powder by photocatalysis. Parameters such as mass of catalyst, geometric irradiated surface, catalyst morphology, and thermal treatment were tested to explain the photocatalytic concentration decrease of nitrogen oxides. According to our working conditions, the conversion rates increased until an optimal value of the TiO₂ weight, 35% of NO concentration and around 20% of NOx, was decomposed by the photocatalysis. The NOx removal increased proportionally with the irradiated geometric surface. The structural transformation of anatase to rutile performed by thermal treatment involved the decrease of the photocatalytic activity.     

SO2长期吸入对大鼠肺组织基因表达谱的影响

采用Affymetrix的基因芯片(RAE230A)技术,研究了SO2长期动态吸入(14mg/m3,1h/d,共30d)后大鼠肺组织基因表达谱的改变.结果表明,与对照组(CK)相比,SO2长期吸入后大鼠肺组织表达上调的基因有173个,其中包括79个已知基因和94个新基因,而表达下调的基因有85个,其中包括46个已知基因和39个新基因.表明:(1)长期吸入SO2的大鼠肺基因表达谱与其CK相比,表达有差异的基因涉及到脂肪酸代谢、免疫、炎症、氧化应激、原癌基因、肿瘤抑制基因和细胞外基质等,表明低剂量长期吸入SO2在体内的机理非常复杂;(2)SO2高剂量短期吸入与低剂量长期吸入后,大鼠肺组织基因表达谱的改变很不一致,表明二者在体内的作用机理不同;(3)SO2可引起多种基因的表达发生改变,这意味着多种基因的表达是易变的、不稳定的,在肺组织中可能存在着SO2诱发的表达不稳定型基因组.表1参19     

二氧化硫与1—己烯的光化学反应动力学

利用ＧＣ／ＭＳ方法研究了ＳＯ２与１－己烯在无氧和有氧体系中光化学反应动力学，确定了ＳＯ２与１－己烯光化学反应的级数，给出了２９３－３３３Ｋ温度范围内总的反应速度常数Ｋ，以及Ｋ与温度的关系、反应的活化能和指前因子。另外，对反应物己醛和２－己酮的生成反应速度常数及其活化能也进行了计算和讨论。     

TiO2光催化剂的超临界CO2萃取法制备及其降解甲基橙的活性

用超临界二氧化碳萃取TiO2醇凝胶制备纳米二氧化钛粉体，对萃取工艺条件进行了讨论，并用XRD，FT-IR，BET和DRS对上述粉体进行表征．以光催化降解甲基橙为模型反应，结果表明，与超临界二氧化碳干燥所得的粒子比较，该工艺干燥的TiO2粉体粒径小，比表面积大，光催化活性较高。     

Ancillary benefits of reduced air pollution in the US from moderate greenhouse gas mitigation policies in the electricity sector

Actions to slow atmospheric accumulation of greenhouse gases also would reduce conventional air pollutants yielding “ancillary” benefits that tend to accrue locally and in the near-term. Using a detailed electricity model linked to an integrated assessment framework to value changes in human health, we find a tax of $25 per metric ton of carbon emissions would yield NO_x-related health benefits of about $8 per metric ton of carbon reduced in the year 2010 (1997 dollars). Additional savings of $4–$7 accrue from reduced investment in NO_x and SO₂ abatement in order to comply with emission caps. Total ancillary benefits of a $25 carbon tax are $12–$14, which appear to justify the costs of a $25 tax, although marginal benefits are less than marginal costs. At a tax of $75, greater total benefits are achieved but the value per ton of carbon reductions remains roughly constant at about $12.     

中国能源消费导致的CO2排放量的差异特征分析

运用一种不产生残差的方法——对数平均迪氏指数法LMDI(logarithmicmeanDivisiaindex),对中国部分省份、区域能源消费导致的二氧化碳排放量进行了分解分析。将二氧化碳排放总量的变化分解成五个主要影响因素,即化石燃料的排放系数、能源消费结构、能源强度、人均GDP和人口总数。研究表明我国各省(地区)的二氧化碳排放量在1996年后呈现零(或负)增长趋势,主要影响因素是能源强度的提高;各省(地区)的二氧化碳排放量地区差异显著。因此,要在全国实现二氧化碳排放量的总体减排,应从提高能源利用效率,调整产业结构,消除地区发展的不平衡,逐步改善能源消费结构等方面考虑。     

Dichlorvos degradation studied by 31P-NMR

We studied the hydrolysis and TiO₂ photocatalysis of the pesticide dichlorvos at pH 2.6–9 using phosphorus-31 nuclear magnetic resonance (³¹P NMR). We found that the hydrolysis of dichlorvos led to the formation of dimethyl phosphate at pH 5.6–9. On the other hand, TiO₂ photocatalysis decomposed dichlorvos into dimethyl phosphate, which further reacted to form monomethyl phosphate at pH 2.6 and 9. Monomethylphosphate was hydrolysed into phosphate at pH 2.6. ³¹P NMR is therefore a promising tool to study the degradation of organophosphorus pesticides.     

锦州市大气污染现状及控制措施

利用大气污染源和环境质量监测等资料，计算分析了锦州市区大气污染现状。结果表明：在锦州市区空气污染以煤烟类为主，汽车尾气成为大气污染源之一。PM10和SO2超过二级标准的天数将近95％出现在采暖期。提出了可行的具体措施，指出采用以集中供热、推广使用天然气、小型锅炉改造工程和控制汽车尾气为主要措施，廉顾绿化，制定市区大气污染治理方案比较合理。     

Accounting for time in Mitigating Global Warming through land-use change and forestry

Many proposed activities formitigating global warming in the land-use change and forestry(LUCF) sector differ from measures to avoid fossilfuel emissions because carbon (C) may be held out ofthe atmosphere only temporarily. In addition, thetiming of the effects is usually different. Many LUCFactivities alter C fluxes to and from the atmosphereseveral decades into the future, whereas fossil fuelemissions avoidance has immediate effects. Non-CO₂ greenhouse gases (GHGs), which are animportant part of emissions from deforestation inlow-latitude regions, also pose complications forcomparisons between fossil fuel and LUCF, since themechanism generally used to compare these gases(global warming potentials) assumes simultaneousemissions. A common numeraire is needed to expressglobal warming mitigation benefits of different kindsof projects, such as fossil fuel emissions reduction,C sequestration in forest plantations, avoideddeforestation by creating protected areas and throughpolicy changes to slow rates of land-use changes suchas clearing. Megagram (Mg)-year (also known as`ton-year') accounting provides a mechanism forexpressing the benefits of activities such as these ona consistent basis. One can calculate the atmosphericload of each GHG that will be present in each year,expressed as C in the form of CO₂ and itsinstantaneous impact equivalent contributed by othergases. The atmospheric load of CO₂-equivalent Cpresent over a time horizon is a possible indicator ofthe climatic impact of the emission that placed thisload in the atmosphere. Conversely, this index alsoprovides a measure of the benefit of notproducing the emission. One accounting methodcompares sequestered CO₂ in trees with theCO₂ that would be in the atmosphere had thesequestration project not been undertaken, whileanother method (used in this paper) compares theatmospheric load of C (or equivalent in non-CO₂GHGs) in both project and no-project scenarios.Time preference, expressed by means of a discount rateon C, can be applied to Mg-year equivalencecalculations to allow societal decisions regarding thevalue of time to be integrated into the system forcalculating global warming impacts and benefits. Giving a high value to time, either by raising thediscount rate or by shortening the time horizon,increases the value attributed to temporarysequestration (such as many forest plantationprojects). A high value for time also favorsmitigation measures that have rapid effects (such asslowing deforestation rates) as compared to measuresthat only affect emissions years in the future (suchas creating protected areas in countries with largeareas of remaining forest). Decisions on temporalissues will guide mitigation efforts towards optionsthat may or may not be desirable on the basis ofsocial and environmental effects in spheres other thanglobal warming. How sustainable development criteriaare incorporated into the approval and creditingsystems for activities under the Kyoto Protocol willdetermine the overall environmental and social impactsof pending decisions on temporal issues.     

MgAlFe复合氧化物氧化吸附SO_2的性质

MgAlFe水滑石在 6 0 0℃以上焙烧后脱去表面水和层间水形成MgAlFe复合氧化物 通过对MgAlFe复合氧化物BET、XRD表征和测定它的吸附硫容 ,发现它对SO2 有优良的氧化吸附性能 吸附SO2 后MgO和尖晶石相消失 ,形成硫酸盐晶相 用氢气对饱和吸附SO2 后的MgAlFe复合氧化物进行还原再生 ,发现它经过 10次吸附还原循环后 ,MgO和尖晶石的晶相依然存在 ,是一种可循环利用脱除SO2 的环境催化材料