Using X-ray computed tomography and micro-Raman spectrometry to measure individual particle surface area, volume, and morphology towards investigating atmospheric heterogeneous reactions

Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography(XCT) and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional(3-D) rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy(FE-SEM) to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle.     

Impacts of Bakken Shale Oil Development on Regional Water Uses and Supply

The Bakken shale play in western North Dakota is one of the largest unconventional oilfields in the United States, but published research about impacts on the region's water resources is rare. In this study, besides examining North Dakota water management policies and activities, we also analyzed three datasets: the Bakken horizontal well completion data (2008‐2014), North Dakota permitted water consumption data (2000‐2014), and groundwater level and streamflow observations in western North Dakota (2000‐2014). We found from 2008 to 2014, the annual total industrial water uses for Bakken shale oil development ranged between 0.5 and 10% of statewide total consumptive water use. The percentage increases were between 3.0 and 40% within the Bakken oil production region. The increased population of temporary oilfield service workers contributed additional domestic water use, which was equivalent to ~15% of annual industrial water use for the shale oil development in the Bakken. Despite being in a semiarid region, the impact of Bakken development on regional water supply was limited because the water in the Bakken was adaptively managed and the region received on average over 20% more precipitation than normal during 2008‐2014. Of the 15 glaciofluvial aquifers under study, 12 have seen water levels increasing or unchanged and the water levels for the remaining 3 aquifers have decreased.     

镁-铝水滑石的制备及其脱色性能

以不同的Mg^2＋与Al^3＋摩尔比制备一系列的镁-铝水滑石，考察镁-铝水滑石对单一品种模拟分散染料废水的脱色效果。实验结果表明，以n（Mg^2＋）：n（Al^3＋）为3：1制得的镁-铝水滑石对模拟分散染料废水的脱色效果最好；脱色处理后的镁-铝水滑石再生后可重复使用，它对模拟分散染料废水的脱色效果与新的镁-铝水滑石的脱色效果几乎没有差别；在模拟分散染料废水pH为10～11、镁-铝水滑石的加入量为1.0g／L、反应2h的条件F，模拟分散染料废水的脱色率为98％。     

医疗废物高温蒸汽集中处置技术探讨

本文依据《关于医疗废物高温蒸汽集中处置要求》对医疗废物的高温蒸汽集中处置技术进行了探讨。     

长三角城市居民家庭直接能耗碳排放空间特征及影响因素研究

目前关于碳排放的研究主要以国家和行政省(自治区、直辖市)为研究对象,围绕城市尺度家庭层面碳排放的研究相对匮乏,而家庭是社会最基本的组成单位,针对相关的碳排放特征及影响问题亟待解决.本文以2007—2016年长三角地区26个地级市数据为样本,测算城市居民家庭直接能耗碳排放量.利用K均值聚类法、空间相关性检验及空间面板建模等方法,考察城市居民家庭直接能耗碳排放量的空间演变分布特征及影响因素.结果表明:①城市居民家庭直接碳排放量高的城市位于长三角中部偏东的位置,排放量低的城市集中在西部位置,中部地区的碳排放量增长速度普遍快于其他地区.②长三角地区城市居民家庭直接能耗碳排放的空间关联程度呈"N"字形趋势,处于高高集聚状态的区域集中在以苏州市等为核心的偏中部地区,处于低低集聚状态的区域集中在西部边缘地区.③前后5年的回归结果对比表明:户均人口数由不显著的正向影响因素转变为重要的抑制因素;户均私家车与每户拥有的城市道路面积联合效应的正向影响作用越来越强烈.研究结论可为城市在动态制定碳减排政策时提供理论依据.     

联邦德国自然灾害保险述评

灾害保险作为减轻灾害损失的重要手段,受到了国际社会的广泛关注。本文评述了德国的自然灾害保险发展体系及保险人、保险业及国家在灾害保险中的职能关系,可为我国开展灾害保险提供借鉴。     

包头市能源消费结构与能效分析

结合2001年~2007年统计数据,从能源消费量、能源种类、重点行业企业能源消费、能源消费结构等方面分析了包头市能源消费现状,并就单位GDP能耗、单位工业增加值能耗等能效指标,与同期全国部分省市及全区各盟市指标进行了对比分析,为包头市优化能源结构、改善环境质量、走新型工业化道路提供参考。     

以聚羟基脂肪酸酯为固体碳源去除地下水中的硝酸盐

研究了可降解聚合物聚羟基脂肪酸酯（PHA）作为固体碳源和生物膜载体去除地下水中硝酸盐的影响因素。结果表明,低温反硝化有较大影响,5℃和10℃时的反硝化速率分别只有30℃时的5%和13%。反硝化对进水pH有较强的适应性,在pH4.5-9.5条件下,反硝化速率介于11.2-15.8mg/（Loh）之间。pH为4.5-8.5时,出水亚硝酸盐的浓度相差不大。DO对以反硝化速率影响不大,当进水DO为0.9mg/L-5.0mg/L时,反硝化速率介于12.6-15.8mg/（Loh）之间,出水NO2-N浓度的最大值为0.15 mg/L。     

湖泊生态系统健康评估初探-以乌梁素海为例

在对湖泊生态系统健康评估的研究的基础上,选用乌梁素海物理化学指标（SD、DO、COD、NH3-N、BOD、TN、TP）数据及生物指标（浮游植物数量、浮游动物数量、底栖动物生物量、水生植物覆盖度、浮游植物叶绿素a）数据等12项指标,利用指标体系法计算乌梁素海生态健康综合指数,结果表明：乌梁素海生态系统综合健康指数总体上呈现明显递减趋势,表明其系统健康状况整体呈下降趋势。该结果客观地反映了乌梁素海近些年来的生态系统的健康状况,为乌梁素海的管理提供了科学依据,为湖泊生态安全调查奠定了基础。     

应用加载磁絮凝技术处理垃圾渗滤液试验研究

垃圾渗滤液是一种成分复杂多变的高浓度难处理有机废水.本研究采用加载磁絮凝技术对垃圾渗滤液进行预处理,并讨论了适宜的磁载体、凝聚剂和絮凝剂的加入量.