地下空间在节能减排中的应用及展望

在能源短缺和环境污染的双重压力下,我国出台多项措施加大节能减排力度。总结概括了地下空间的几种类型,认为盐岩洞穴、废弃矿洞、废弃油井、枯竭油气层等地下空间经过技术改造,可以埋存CO2、固体垃圾、废弃核原料,储存油气,地热利用等,能创造可观的社会价值和环境保护效益,可作为节能减排的一种有效措施。以山东地区为例,调研分析了山东多处地下空间利用现状,给出了地下空间的三种发展方向。     

Ultrafine particle emission characteristics of diesel engine by on-board and test bench measurement

This study investigated the emission characteristics of ultrafine particles based on test bench and on-board measurements. The bench test results showed the ultrafine particle number concentration of the diesel engine to be in the range of (0.56-8.35) × 10⁸ cm^-3. The on-board measurement results illustrated that the ultrafine particles were strongly correlated with changes in real-world driving cycles. The particle number concentration was down to 2.0 × 10⁶ cm^-3 and 2.7 × 10⁷ cm^-3 under decelerating and idling operations and as high as 5.0 × 10⁸ cm^-3 under accelerating operation. It was also indicated that the particle number measured by the two methods increased with the growth of engine load at each engine speed in both cases. The particle number presented a "U" shaped distribution with changing speed at high engine load conditions, which implies that the particle number will reach its lowest level at medium engine speeds. The particle sizes of both measurements showed single mode distributions. The peak of particle size was located at about 50-80 nm in the accumulation mode particle range. Nucleation mode particles will significantly increase at low engine load operations like idling and decelerating caused by the high concentration of unburned organic compounds.     

Effects of WOx modification on the activity, adsorption and redox properties of CeO2 catalyst for NOx reduction with ammonia

A series of WO₃/CeO₂ (WOx/CeO₂) catalysts were synthesized by wet impregnation of ammonium metatungstate on a CeO₂ support. The resulting solid acid catalysts were characterized by X-ray diffraction (XRD), UV-Vis spectroscopy (UV-Vis), Raman spectroscopy (Raman), in-situ Fourier transform infrared spectroscopy (in-situ FT-IR) of ammonia adsorption, NH₃-TPD, H₂ temperature-programmed reduction (H₂-TPR), NH₃/NO oxidation and activity measurements for NOx reduction by NH₃ (NH₃-SCR). The results show that polytungstate (WOx) species are the main species of tungsten oxide on the surface of ceria. The addition of tungsten oxide enhances the Brönsted acidity of ceria catalysts remarkably and decreases the amount of surface oxygen on ceria, with strong interaction between CeO₂ and WOx. As a result, the N₂ selectivity of NH₃ oxidation and NH₃-SCR at high temperatures (> 300℃) is enhanced. Therefore, a wide working temperature window in which NOx conversion exceeds 80% (NOx conversion > 80%) from 200 to 450℃, is achieved over 10 wt.% WOx/CeO₂ catalyst. A tentative model of the NH₃-SCR reaction route on WOx/CeO₂ catalysts is presented.     

城市轨道交通浮置式减振措施的减振降噪效果

从分析轨道交通地下隧道振动传播特征出发,说明了地下振动的传播规律,并给出了不同埋深条件下地下振动影响范围的经验公式;结合地下振动激发频率特征的分析,对减振措施的减振效果的合理评价量进行了分析,指出采用Z计权减振效果评价量将获得与实际应用效果一致的降噪效果。结合两种浮置式减振措施减振降噪效果的实测,指出浮置板道床的减振效果应采用安装减振垫浮置板道床前后桥面的Z振级差来评价,而不宜采用轨面与桥梁直接的振级落差来评价。对橡胶减振垫以及钢弹簧浮置板的实测减振降噪效果进行了介绍。     

高速铁路车轮减振降噪优化方法

高速铁路车轮的振动辐射噪声在轮轨滚动辐射噪声中占有很大的比重,而且在1500Hz以上的频段内占主导,对列车车轮进行优化设计,通过改变车轮的形状,可以达到较好的减振降噪效果。本文对高速铁路车轮优化方法进行详细的分析评论,并提出相应的问题和改进的方向。     

我国钢铁生产企业氮氧化物减排形势研究

针对国家"十二五"氮氧化物减排的紧迫形势,介绍了我国钢铁企业排放氮氧化物污染现状,提出烧结工序烟气氮氧化物控制是钢铁生产企业氮氧化物减排的重点,在对相关技术优缺点进行分析的基础上,总结了存在的主要问题、困难和发展趋势,提出了钢铁行业氮氧化物减排的对策和建议,为我国氮氧化物污染控制提供支撑。     

建设用地扩张与碳排放效应的库兹涅茨曲线假说及验证

论文基于无锡市1996—2008年的土地利用和能源消耗数据,分析了无锡市13 a间建设用地扩张及碳排放特征,并构建了建设用地比例与碳排放强度之间的库兹涅茨曲线模型,对无锡市建设用地扩张与碳排放效应之间的相关关系进行了实证研究,尝试验证库兹涅茨曲线在建设用地扩张与碳排放强度之间的存在性。结果表明:①建设用地总量在1996—2008年间迅速增长,绝对增长量44 032.97 hm²,且除了农村居民点逐渐下降以外,其余地类均呈逐年增长态势,无锡市1996—2008年间的碳排放基本上也呈现逐年增长趋势,绝对增长量1 936.38×10⁴ t;②建设用地总量与碳排放强度之间呈倒U型曲线关系,即随着建设用地扩张至拐点后,碳排放强度则逐渐下降,且拐点位于建设用地比例1.91%附近,但是目前仅仅刚开始出现拐点的迹象,表明目前无锡市建设用地扩张还未完全达到集约及精明增长的标准,建设用地扩张对碳排放而言仍然具有较强的推动作用,但是可以预见,随着产业结构调整和能源技术的提高,碳排放强度会逐渐进入下降的阶段;③城市用地与碳排放强度之间为三次曲线关系,建制镇用地、农村居民点用地与碳排放强度之间分别为正相关和负相关线性关系,其他建设用地与碳排放强度之间则存在一种不明显的库兹涅茨曲线关系。建设用地地类组成的不同会导致不同形态的库兹涅茨曲线,由于城市用地和建制镇用地对碳排放具有明显的驱动作用,其比例的提高亦会促使库兹涅茨曲线更加陡峭,并延缓库兹涅茨曲线拐点的到来。     

基于遥感资料的中国东部地区植被VOCs排放强度研究

本研究充分基于遥感资料获取中国东部地区叶面积指数和叶生物量的最新信息,并广泛调研了植被VOCs排放因子的最新研究进展,以2008—2010年的植被和气象的平均状态为背景,基于MEGAN排放模型,研究了中国东部地区植被VOCs(BVOCs)排放的时空分布特征.结果表明,我国东部地区BVOCs年排放总量为11.3×106t(以C计,下同),其中异戊二烯(ISOP)、单萜烯(MON)和其它VOC(OVOC)质量分数(下同),分别为44.9%、31.5%、23.6%.BVOCs排放呈现明显的季节变化特征,春、夏、秋、冬4个季节分别占全年的11.2%、71.8%、14.1%和3.0%.空间分布上,排放高值区主要分布于大小兴安岭、长白山脉、秦岭大巴山脉、东南丘陵、海南等植被茂密的区域,年均排放强度一般在1500～6000kg·km-·2a-1之间,福建、广东、江西、浙江、湖南、湖北等省份BVOCs的排放总量与平均排放强度均较高.本研究所得到的高时空分辨率的BVOCs排放清单,可以为区域环境与气候的数值模拟研究提供基础.     

Ammonium-dependent regulation of aerobic methane-consuming bacteria in landfill cover soil by leachate irrigation

The impacts of landfill leachate irrigation on methane oxidation activities and methane-consuming bacteria populations were studied by incubation of landfill cover soils with leachate and (NH₄)₂SO₄ solution at different ammonium concentrations. The community structures and abundances of methane-oxidizing bacteria (MOB) and ammonia-oxidizing bacteria (AOB) were examined by PCRDGGE and real-time PCR. Compared with the pure (NH₄)₂SO₄ solution, leachate addition was found to have a positive effect on methane oxidation activity. In terms of the irrigation amount, ammonium in leachate was responsible for the actual inhibition of leachate. The extent of inhibitory effect mainly depended on its ammonium concentration. The suppression of the predominant methaneconsuming bacteria, type I MOB, was responsible for the decreased methane oxidation activity by ammonium inhibition. Methaneconsuming bacteria responded diversely in abundance to ammonium. The abundance of type I MOB decreased by fivefold; type II MOB showed stimulation response of fivefold magnification upon the first addition but lessened to be lower than the original level after the second addition; the amount of AOB was stimulated to increase for 20-30 times gradually. Accumulated nitrate from nitrification strengthened the ammonium inhibition on type I and type II MOB, as a result, repetitive irrigation was unfavorable for methane oxidation.     

零价铁还原和吸附去除水中污染物的研究进展

近年来,零价铁以其低毒、廉价、易操作且对环境不会产生二次污染等优点,在水污染治理中受到重视。文章介绍了零价铁处理污水的机理,对利用零价铁的还原和吸附作用去除污水中的氯代有机物、硝基芳香族化合物、偶氮染料、重金属、高氯酸盐、硝酸盐等的研究情况进行了综述,指出了零价铁废水处理技术的研究方向。