硫酸盐还原条件下三氯乙烯的降解研究

三氯乙烯(TCE)是地下水和土壤中主要的有机污染物之一.以受TCE等氯代烃严重污染的地下泥样为材料,采用室内模拟的方法.研究硫酸盐初始质量浓度为100、500、2 500 mg/L时.硫酸盐对TCE降解的影响.结果表明.高浓度硫酸盐更有利于TCE的降解;在硫酸盐还原条件下,通过添加2-溴乙基磺酸钠抑制产甲烷菌.发现产甲烷菌在TCE的降解过程中起到很重要的作用;硫酸盐浓度变化与TCE降解趋势一致.     

光源和溶剂对十溴联苯醚光降解的影响

研究了不同光源和溶剂对十溴联苯醚(DecaBDE)光降解特性的影响,并对其降解产物进行了探讨.结果表明,在所试光源和溶剂条件下,DecaBDE均有一定程度的光降解,且都近似符合一级降解动力学.同一光源下,不同溶剂对DecaBDE降解表现出不同的影响.在太阳光照射下,DecaBDE降解速率为甲苯>甲醇>正己烷>正己烷/丙酮>甲醇/水>乙醇/水;在模拟光源照射下,DecaBDE降解速率为甲苯>甲醇>甲醇/水>乙醇/水>正己烷>正己烷/丙酮;在紫外光照射下,DecaBDE降解速率为甲苯>甲醇>正己烷/丙酮>正己烷>甲醇/水>乙醇/水.同一溶剂中,DecaBDE降解速率均为紫外光>太阳光>模拟光源.尽管光源和溶剂对DecaBDE降解速率产生了一定影响,但降解途径基本一致,均为DecaBDE经光解脱溴产生低溴联苯醚.     

Measuring atmospheric composition change

Scientific findings from the last decades have clearly highlighted the need for a more comprehensive approach to atmospheric change processes. In fact, observation of atmospheric composition variables has been an important activity of atmospheric research that has developed instrumental tools (advanced analytical techniques) and platforms (instrumented passenger aircrafts, ground-based in situ and remote sensing stations, earth observation satellite instruments) providing essential information on the composition of the atmosphere. The variability of the atmospheric system and the extreme complexity of the atmospheric cycles for short-lived gaseous and aerosol species have led to the development of complex models to interpret observations, test our theoretical understanding of atmospheric chemistry and predict future atmospheric composition. The validation of numerical models requires accurate information concerning the variability of atmospheric composition for targeted species via comparison with observations and measurements.In this paper, we provide an overview of recent advances in instrumentation and methodologies for measuring atmospheric composition changes from space, aircraft and the surface as well as recent improvements in laboratory techniques that permitted scientific advance in the field of atmospheric chemistry. Emphasis is given to the most promising and innovative technologies that will become operational in the near future to improve knowledge of atmospheric composition. Our current observation capacity, however, is not satisfactory to understand and predict future atmospheric composition changes, in relation to predicted climate warming. Based on the limitation of the current European observing system, we address the major gaps in a second part of the paper to explain why further developments in current observation strategies are still needed to strengthen and optimise an observing system not only capable of responding to the requirements of atmospheric services but also to newly open scientific questions.     

酸渣制备无水硫酸钠

采用炼油厂酸渣经水稀释后,添加含钠化合物进行中和反应,制备无水Na_2SO_4.最佳工艺条件为:将酸渣用水稀释20倍,按n(Na_2CO_3):n(SO_4~(2-))=1.10或n(NaOH):n(SO_4~(2-))=1.20的比例加入Na_2CO_3,溶液或NaOH溶液,油水分离去除油相后蒸发、干燥,在650℃下灼烧后溶解、过滤、蒸发、结晶,得到Na_2SO_4产品.NaCO_3法可将酸渣中约78%的SO_4~(2-)转化到产品Na_2SO_4中;NaOH法可将酸渣中约66%的SO_4~(2-)转化到产品Na_2SO_4中.制备的无水Na_2SO_4产品均达到GB/T6009-2003<工业无水硫酸钠>二类标准.     

Direct quantification of organic acids in aerosols by desorption electrospray ionization mass spectrometry

Desorption electrospray ionization mass spectrometry (DESI-MS) is a novel analytical technique for direct surface analysis under ambient conditions. In this work, we report the first application of DESI-MS to the analysis of organic acids in atmospheric aerosols. We took oxalic and oleic acids as two typical representatives of the particulate organic acids. Experimental parameters for DESI-MS were optimized to enhance the signal intensity. Calibrations for both acids showed great linearity over a concentration range of 5 orders of magnitude with correlation coefficients R²>0.99. The relative standard deviation (RSD) was less than 10% for oxalic acid and within 15% for oleic acid measurement. The detection limits for oxalic acid and oleic acid are about 1 pg mm^?2 with 5–10 s sampling time. Mass concentrations of organic acids in both laboratory-generated biomass burning and ambient aerosols were measured by DESI-MS and the results agree well with the ion chromatography (IC) and GC–MS values. This work demonstrates that DESI-MS is a promising method for rapid quantitative analysis of organic acids in atmospheric aerosols.     

On the Laws and Causes of Socio-economic Territorial Differentiation in Minority Areas in China

On the basis of applying quantitative and qualitative approaches as well as GIS technology, this paper established an index system to make a comprehensive evaluation on socioeconomic development of minority areas in China. The result showed that socio-economic development in minority area presents a series of characteristics that the north is high and the south is low, center-margin pattern is obvious and the areas with middle and lower development indices are distributed centrally and continuously. However, the causes of the socioeconomic characteristics mainly include natural conditions, economic development basic, population cultural quality, regional combination and development conditions of mineral and energy resources, informal institutional factors and distribution of major traffic lines.     

über die Notwendigkeit der wirkungsorientierten Analytik in einer umfassenden Wasserforschung

Ohne Zusammenfassung Verantwortliche Herausgeber: Jan Schwarzbauer · Peter Heininger · Evelyn Claus

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剩余污泥超声预处理后水解酸化特性

为探讨剩余污泥超声预处理后的水解酸化特性,考察了0.6 W/mL、5 min和1 W/mL、5 min 2种超声预处理条件下污泥水解酸化过程有机质、氮、磷的释放情况。实验结果表明,2种超声预处理均可促进污泥水解酸化,并且0.6 W/mL比1 W/mL的超声预处理更有利于SCOD的释放、VFAs的产生以及氮和磷的释放;水解酸化初期,超声预处理比未经超声预处理的污泥在有机质、氮、磷释放率上差异非常明显,随着水解酸化的进行,有机质和氮释放率差异仍很明显,而磷释放程度逐渐接近;经0.6 W/mL超声预处理,污泥水解酸化3 d后,SCOD释放率、VFAs浓度、TN释放率和NH4+-N释放率分别是未经处理污泥的1.85、2.63、1.85和1.41倍,而TP和PO43--P释放率较未经处理污泥仅分别多2.44和1.23个百分点。研究表明,控制适宜的声能密度、超声时间和水解酸化进程是超声预处理强化剩余污泥水解酸化效果的关键。     

Changes in the spatial patterns of human appropriation of net primary production (HANPP) in Europe 1990–2006

Understanding patterns, dynamics, and drivers of land use is crucial for improving our ability to cope with sustainability challenges. The human appropriation of net primary production (HANPP) framework provides a set of integrated socio-ecological indicators that quantify how land use alters energy flows in ecosystems via land conversions and biomass harvest. Thus, HANPP enables researchers to systematically and consistently assess the outcome of changes in land cover and land-use intensity across spatio-temporal scales. Yet, fine-scale HANPP assessments are so far missing, an information important to address site-specific ecological implications of land use. Here, we provide such an assessment for Europe at a 1-km scale for the years 1990, 2000, and 2006. The assessment was based on a consistent land-use/biomass flow dataset derived from statistical data, remote sensing maps, and a dynamic global vegetation model. We find that HANPP in Europe amounted to ~43 % of potential productivity, well above the global average of ~25 %, with little variation in the European average since 1990. HANPP was highest in Central Europe and lower in Northern and Southern Europe. At the regional level, distinct changes in land-use intensity were observed, most importantly the decline of cropland areas and yields following the breakdown of socialism in Eastern Europe and the subsequent recovery after 2000, or strong dynamics related to storm events that resulted in massive salvage loggings. In sum, however, these local dynamics cancelled each other out at the aggregate level. We conclude that this finding warrants further research into aspects of the scale-dependency of dynamics and stability of land use.