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.     

简述二噁英降解方法的研究进展

二噁英是一类剧毒的持久性有机污染物和一级致癌物质。脱氯降解是降低二噁英毒性的有效途径之一。本文首先介绍了二噁英的种类、来源和危害,其次对二噁英的降解方法包括光降解、光-Fenton降解、生物降解、热降解、化学降解脱氯作了简要评述,比较了各种降解方法的优劣。     

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.     

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。     

Following Old Paths or Shaping New Ones in Natura 2000 Implementation? Mapping Path Dependency in Instrument Choice

This article reviews the influence of two specific European Union (EU) laws, the Birds and Habitats Directives, on the choice of national policy instruments by Member States. Both Directives leave the choice for policy instruments to manage the sites designated under the Directives to the Member States. Using path dependency as a leading concept, this article analyses the continuity or changes in policy instruments due to the implementation of the Directives in 15 countries. This article shows that the tendency to use existing instruments to implement EU policy is limited, as in almost all countries new instruments were developed. Yet, states do tend to choose instruments from their predominant policy instrument mix and preferred implementation style to address the management requirements of the Directives. Additionally, in Central and Eastern European countries where the implementation of EU policy coincided with a process of transition to a market economy, new instruments were introduced outside the existing implementation style. The introduction of new policy instruments is the result of historical turns, domestic pressure and a shift to new modes of governance. National case studies are needed to shed more light on the interaction between EU policy and domestic factors during the process of instrument choice.     

生态田处理油田污水的探索与实践

生态田污水处理技术具有低投资、低能耗、低运行费用等诸多优点,结合油田所处的地理位置及实际生产情况,利用生态田天然植物的生物效能,对油田污水处理后用于植被灌溉,并且针对处理过程中存在的问题提出了工艺改造对策措施,最终实现净化污水的目的。     

金属离子对菌株JY01生长和苯酚降解性能的影响研究

金属可能通过生理和生态两方面对微生物的苯酚降解过程产生重要影响.为了提高芽孢杆菌Bacillus sp.JY01(以下称菌株JY01)的苯酚降解效率,探讨了6种金属离子(Ba2+、Cu2+、Co2+、Fe3、Zn2+、pb2+)对其生长和苯酚降解性能的影响.结果表明,在质量分数为0.001％～0.050％时,Cu2+、Zn2+、Co2、Fe3+、Ba2+、pb2+对菌株JY01的生长和苯酚降解均有抑制作用,并且抑制作用总体随金属离子浓度的升高而增强,当6种金属的质量分数分别达到0.005％时,菌株JY01对苯酚的降解能力为Ba2+ ＜Cu2+ ＜Co2+ ＜Fe3+ ＜Zn2+ ＜pb2+;金属离子通过影响菌株JY01的生长状况来影响其苯酚降解性能;很多金属离子对菌株JY01生长有明显抑制作用,因此在实际生物处理含苯酚废水时,要考虑废水中金属离子对降解菌生长状况的影响.