Responses of CH(4), CO(2) and N(2)O fluxes to increasing nitrogen deposition in alpine grassland of the Tianshan Mountains

To assess the effects of nitrogen (N) deposition on greenhouse gas (GHG) fluxes in alpine grassland of the Tianshan Mountains in central Asia, CH₄, CO₂ and N₂O fluxes were measured from June 2010 to May 2011. Nitrogen deposition tended to significantly increase CH₄ uptake, CO₂ and N₂O emissions at sites receiving N addition compared with those at site without N addition during the growing season, but no significant differences were found for all sites outside the growing season. Air temperature, soil temperature and water content were the important factors that influence CO₂ and N₂O emissions at year-round scale, indicating that increased temperature and precipitation in the future will exert greater impacts on CO₂ and N₂O emissions in the alpine grassland. In addition, plant coverage in July was also positively correlated with CO₂ and N₂O emissions under elevated N deposition rates. The present study will deepen our understanding of N deposition impacts on GHG balance in the alpine grassland ecosystem, and help us assess the global N effects, parameterize Earth System models and inform decision makers.     

纯电动汽车驱动电机全生命周期评价

基于生命周期评价(LCA)理论,运用Ga Bi 6软件建模,对荣威E50纯电动汽车驱动电机全生命周期环境排放和资源消耗进行了评价,对比分析在中国不同区域使用下驱动电机生命周期过程资源环境影响,并对驱动电机生命周期过程中的生产制造能耗、使用能耗和原材料回收率做敏感性分析.结果表明,驱动电机全生命周期过程各环境影响类型指数排序为APGWPPOCPEPODP,且对环境的影响主要发生在使用阶段,其次是原材料获取和制造阶段.各大区域电网下驱动电机全生命周期过程环境排放影响从大到小为华东电网东北电网西北电网华北电网南方电网华中电网.从敏感性分析结果可知,使用能耗对驱动电机生命周期环境排放影响的敏感度大于生产制造能耗;铜的回收率对矿产资源消耗影响的敏感度远大于钢和铝的回收率.     

含油污泥石油烃在生物强化堆肥处理中降解特性研究

为提高含油污泥的生物降解效率,通过混合菌剂强化堆肥法处理含油污泥的小试试验,采用GC-MS图谱分析技术对石油烃中正构烷烃、藿烷、甾烷的降解规律进行分析.结果表明:7%的油泥经微生物强化堆肥处理49 d后降解率在85%以上.石油烃中3种系列的降解难易顺序为正构烷烃>藿烷>甾烷,从降解规律来看,微生物降油复合菌剂对高碳数正构烷烃的平均降解率（75.55%）大于对低碳数正构烷烃的平均降解率（62.98%）,说明总石油烃中降解率最大的是正构烷烃.微生物降油复合菌剂对藿烷的降解率在90%以上,其对22S-31,32,33,34-四升藿烷的降解率最高.微生物降油复合菌剂能够促进孕甾烷的转化,且对重排甾烷的降解效果较明显,对甾烷类化合物中4-甲基-24-乙基-胆甾烷的降解效果最好.微生物降油复合菌剂对正构烷烃的奇偶碳降解优势不明显;藿烷的立体构型转化参数大于甾烷的立体构型转化参数,这也解释了藿烷的降解易于甾烷的原因.研究显示,微生物降油复合菌剂对石油烃中正构烷烃、藿烷、甾烷的降解效果均较好.      

Assessment of different methods in analyzing motor vehicle emission factors

Environmental Science and Pollution Research - To explore the emission characteristics of vehicle’s pollutants is of great significance to prevent and control the diffusion of pollutants....