MnOX/ACF低温选择性催化还原烟气中的NO

进行了MnOX/ACF(活性炭纤维)对低温选择性催化还原(SCR)NO的影响研究.实验表明,ACF先经浓酸预氧化,然后再负载MnOX催化剂,对NO脱除率的提高较明显,并且以20%(质量分数)HNO3预氧化处理的效果最佳.比较了相同制备条件和相同负载量下的MnOX/ACF和V2O5/ACF的催化效果,认为在同等条件下MnOX的活性高于V2O5.考察了不同负载量的MnOX对NO脱除率的影响,较理想的MnOX负载量为12%(质量分数).在此基础上就不同的催化剂质量和烟气流速比(W/F)对NO脱除率的影响进行了研究,结果表明,在低温、W/F为2～3 mg/(mL·min-1)时NO的去除率较高.     

城市生活垃圾问题研究的系统动力学方法

利用被称为战略与策略实验室的系统动力学方法,建立了城市生活垃圾问题的系统动力学研究模型;以北京市为实例,探讨了垃圾排放及污染随人口和经济发展的变化,以及污染和占地损失、绿色GDP核算、居民家庭、企事业单位生活垃圾与建筑垃圾组合收费方案等问题.     

Long-term agricultural contamination shaped diversity response of sediment microbiome

The pollution caused by agricultural production poses a threat to the ecological integrity of river ecosystems, altering the structure and function of river ecosystems. Differences in microbial community structure provide useful information about the impact of agricultural pollution on the biological integrity of ecosystems, but generally convey little information regarding ecosystem functions. In this study, using Illumina MiSeq sequencing technology based on the 16S rRNA gene, river sediment samples associated with four different types of agricultural pollution were comprehensively analyzed. The results show that the total organic carbon (TOC) content was highest at the YZS site (animal husbandry sewage) among the assayed sites, but the species richness and uniformity were lowest at this site, which may have been caused by the high nutrient source of the sewage. Furthermore, in the three YZS samples affected by the long-term discharge of aquaculture tail-water, the unique genus Dechloromonas and the genus Candidatus-Competitor were observed, which are strongly correlated with phosphorus conversion. The formation of network modules may correspond to the coexistence of functional bacteria accustomed to multiple niche combinations under different agricultural pollution conditions in river sediments. According to the PICRUSt functional prediction, the bacterial community in the agricultural polluted river sediment primarily harbored 46 subfunctions, exhibiting richness of functions. Overall, our results provide a more comprehensive understanding of the structure and ecological processes associated with the aggregation of bacterial communities, which is beneficial for the management of river environments.     

拟除虫菊酯类农药对水生生物的毒性评价研究

拟除虫菊酯类农药对水生生物的危害是当前农业环境的一大问题。作者进行了七项试验从不同角度探讨了拟除虫菊酯类农药对水生生物的毒性影响,为合理使用拟除虫菊酯类农药提供了科学依据。      

珠江口海区的碳贮量

本文根据实测资料,分别计算了珠江口海区各碳贮库的碳贮量,计算得海水贮库碳贮量约为300×10~6kg,颗粒碎屑碳贮库约11×10~6kg,生物碳贮库约3×10~6kg,表层沉积物碳贮库约698×10~6kg,并由计算结果讨论了珠江口碳贮库各类碳的分配情况。     

消除及回收烟气中SO2的糠醛渣活性炭研究

利用糠醛渣废料研制成一种新型改质炭(简称渣炭),采用温度程序脱附(TPD),色谱质谱连用(GC-MS),比表面测定(BET),静态与动态吸附以及二氧化硫氧化反应等方法,对渣炭的物化性质进行表征,并与几种商品炭进行比较;考察其反应条件,表明该渣炭无需添加任何活性组分便具有良好的脱硫性能,适用于烟气脱硫制酸过程。认为渣炭上某些羟基及羰基表面基团是脱硫活性中心,丰富的中孔有利于反应扩散。在烟气量5000Nm~3/h的中试装置上,于空速500h~(-1)。入口烟温70℃以及二氧化硫浓度1500—2500ppm的条件下,对工业放大渣炭进行验证,连续累计操作6000多小时,二氧化硫消除率约70％及副产硫酸的浓度约30％,并且,该渣炭的成本可以比碘炭降低40％左右。     

世界食物安全态势及中国对策

本文阐述了世界食物安全现状及发展趋势,介绍了不同国家实现食物安全的模式及其政策选择,分析了中国食物安全成就及未来所面临的困境和挑战,根据国情并借鉴国际经验提出了中国实现21世纪国家食物安全可持续性的战略举措。     

冀西北半干旱区等高植物篱面源污染控制机理

坡面养分流失是造成面源污染的主要形式.本研究利用冀西北黄土丘陵区的试验小区的长年观测资料,并结合野外全坡面大型人工模拟降雨试验及室外实验数据,分析了冀西北温带及半干旱地区等高植物篱对面源污染控制机理,得出在暴雨条件下细沟产生并导致侵蚀剧烈增加的临界坡长为10～15m;研究揭示出冀西北半干旱区面源污染形态以泥沙携带养分流失为主,等高植物篱控制面源污染的途径是控制土壤颗粒中的养分流失.     

L-精氨酸溶剂化合成金属有机骨架化合物及其吸附CO2的性能

采用L-精氨酸对传统均苯三甲酸（BTC）溶剂热法合成的Cu基金属有机骨架化合物（Cu-BTC）进行改性,得到新型化合物（Cu-BTC-Arg）,并通过固定床动态吸附实验考察了Cu-BTC-Arg和Cu-BTC吸附CO2的性能。表征结果显示：L-精氨酸只是辅助化溶剂,并未配位至Cu2+上;Cu-BTC-Arg比Cu-BTC具有更小的晶粒尺寸、更大的比表面积和微孔体积。实验结果表明,两种不同L-精氨酸加入量合成的Cu-BTC-Arg均在室温、烟气中无水蒸气、烟气流量80 mL/min的条件下CO2吸附量最大,吸附接近饱和时的CO2吸附量均为4.9 mmol/g,远高于Cu-BTC的CO2吸附量。Cu-BTC-Arg对CO2的吸附以物理吸附为主。     

Spatiotemporal distribution and the characteristics of the air temperature of a river source region of the Qinghai-Tibet Plateau

As the backland of the Qinghai-Tibet Plateau, the river source region is highly sensitive to changes in global climate. Air temperature estimation using remote sensing satellite provides a new way of conducting studies in the field of climate change study. A geographically weighted regression model was applied to estimate synchronic air temperature from 2001 to 2015 using Moderate-Resolution Imaging Spectroradiometry (MODIS) data. The results were R²?=?0.913 and RMSE?=?2.47 °C, which confirmed the feasibility of the estimation. The spatial distribution and variation characteristics of the average annual and seasonal air temperature were analyzed. The findings are as follows: (1) the distribution of average annual air temperature has significant terrain characteristics. The reduction in average annual air temperature along the elevation of the region is 0.19 °C/km, whereas the reduction in the average annual air temperature along the latitude is 0.04 °C/degree. (2) The average annual air temperature increase in the region is 0.37 °C/decade. The average air temperature increase could be arranged in the following decreasing order: Yangtze River Basin > Mekong River Basin > Nujiang River Basin > Yarlung Zangbo River Basin > Yellow River Basin. The fastest, namely, Yangtze River Basin, is 0.47 °C/decade. (3) The average air temperature rise in spring, summer, and winter generally increases with higher altitude. The average annual air temperature in different types of lands following a decreasing order is as follows: wetland > construction land > bare land glacier > shrub grassland > arable land > forest land > water body and that of the fastest one, wetland, is 0.13 °C/year.