商业SCR烟气脱硝催化剂钙中毒研究

使用2种不同浓度的前驱体溶液(Ca(NO3)2和Ca(CH3COO)2溶液)浸渍新鲜商业SCR(selective catalytic reduction)烟气脱硝催化剂,并对浸渍中毒后催化剂的性能进行了研究。实验结果表明,物理中毒在本研究中占主导位置,化学中毒并不明显。采用离子色谱、氮气吸附-脱附分析、红外光谱分析、X射线衍射分析、扫面电镜分析等多种表征技术对中毒后催化剂进行了表征。结果表明,中毒后催化剂孔结构性质发生了变化,特别是Ca(CH3COO)2溶液浸渍催化剂,内部孔道堵塞较为严重。X射线衍射分析和扫描电镜分析也从另一方面说明了CaCO3的出现及积累导致催化剂脱硝效率降低。此外,催化剂红外光谱分析从表面活性位的角度说明了本研究催化剂化学中毒现象并不明显。     

基于Voronoi图和时间效应的矿柱失稳预测

针对香炉山大规模地下采空区,借助Voronoi图确定分摊面积来模拟矿柱荷载分布、矿柱破坏、荷载转移以及荷载重新分布的过程,从而确定现阶段的不稳定矿柱,并在此基础上考虑时间效应。用该方法可得出,目前香炉山钨矿不稳定矿柱的失稳不会造成大规模的坍塌,考虑时间效应,则20年时间效应内二四坑口的南区有发生连续坍塌的可能。为防止矿柱发生大范围坍塌,结合香炉山钨矿的实际情况,最终确定胶结充填法为该矿山当前处理空区的最适宜方法。     

Formation of submicron sulfate and organic aerosols in the outflow from the urban region of the Pearl River Delta in China

Size-resolved chemical compositions of non-refractory submicron aerosols were measured using a quadrupole Aerodyne aerosol mass spectrometer at a rural site near Guangzhou in the Pearl River Delta (PRD) of China in the summer of 2006. Two cases characterized as the outflows from the PRD urban region with plumes of high SO₂ concentration were investigated. The evolution of sulfate size distributions was observed on a timescale of several hours. Namely mass concentrations of sulfate in the condensation mode (with vacuum aerodynamic diameters (D_va) < 300 nm) increased at a rate of about 0.17–0.37 ppbv h^?1 during the daytime. This finding was consistent with the sulfuric acid production rates of about 0.17–0.3 ppbv h^?1, as calculated from the observed gas-phase concentrations of OH (～3.3 × 10⁶–1.7 × 10⁷ cm^?3) and SO₂ (～3–21.2 ppbv). This implies that the growth of sulfate in the condensation mode was mainly due to gas-phase oxidation of SO₂. The observed rapid increase was caused mainly by the concurrent high concentrations of OH and SO₂ in the air mass. The evolution of the mass size distributions of m/z 44, a tracer for oxygenated organic aerosol (OOA), was very similar to that of sulfate. The mass loadings of m/z 44 were strongly correlated with those of sulfate (r² = 0.99) in the condensation mode, indicating that OOA might also be formed by the gas-phase oxidation of volatile organic compound (VOC) precursors. It is likely that sulfate and OOA were internally mixed throughout the whole size range in the air mass.     

活性炭纤维电极法烟气脱硫研究

用活性炭纤维做电极,对烟气进行吸附氧化脱硫研究。探讨了活性炭纤维电极的吸附性能及化学氧化过程中SO2的转化规律。试验表明,活性炭纤维电极具有良好的导电性与吸附性,脱硫率达到95％,其中77％的SO2经电化学氧化为硫酸,同时这一过程可使活性炭纤维再生,延长其使用周期。     

暴雨内涝对城市社区居民出行影响的初步分析——以上海市普陀区金沙居委地区为例

开展城市社区暴雨内涝模拟,初步分析受影响的居民数量.以上海市普陀区金沙居委地区为案例,利用上海市暴雨经验公式计算重现期为50年、100年、500年三种不同情景下的1h降水量,以修正的SCS模型计算径流量.结合上海市排水管网系统的运行状况和实测的研究区相对高程,模拟9种不同情景下暴雨积水的淹没深度,分析不同情景下受影响的房屋分布和对居民出行的影响.随着暴雨强度的增强,排水管网系统功能的失效,积水区域由研究区中部不断扩大.在重现期为500年的情景下,在排水系统完全失效的情况下,最大淹没深度可达0.405 m,道路积水影响出行的人数达到5 970人,占研究区总人口数的87％,已经严重影响到当地居民的日常生活和出行.     

Spatial variations of macrozoobenthos and sediment nutrients in Lake Yangcheng: Emphasis on effect of pen culture of Chinese mitten crab

We determined the effect of Chinese mitten crab (CMC) pen culture on the quantified spatial distribution of the macrozoobenthic community and sediment nutrients in Lake Yangcheng. Redundancy analysis indicated that water temperature, macrophyte occurrence, sediment type, and crab culture were the main environmental factors that influence the spatiotemporal macrozoobenthic distribution. Macrozoobenthic assemblages in the lake were characterized by eutrophic indicator species. In the most polluted estuaries, the abundance and diversity indices of the whole community and abundance of chironomids and oligochaetes were significantly depressed, and sediment carbon (C) and phosphorus (P) were significantly enhanced compared with those in the western, middle (MB), and eastern basin (EB). Crab culture in this lake had significant effects on the species composition of the macrozoobenthic community in one of three CMC culture pens (CP), and generally depressed the abundance of most chironomid and oligochaete species. Significantly increased diversity, evenness, sediment carbon and nitrogen content, and sediment C:P ratio in the CP were found compared with those in the three basins. However, no conspicuous difference in sediment P content between the CP and the two basins of MB and EB was detected. Our results showed that the enhanced diversity and evenness of macrozoobenthos might be associated with the joint effect of macrophyte planting and crab predation, and macrophyte planting may modify the effects of CMC culture by leading to disproportional accumulation of C and N in the sediment relative to P in the CP of the lake.     

近年来淮河干流区水质变化及原因分析

频繁的水旱灾害和严重的水污染是治理淮河的两大难题,入洪泽湖口以上的淮河干流区尤其突出。本文主要分析了近年来淮河干流区的水质情况。首先简要介绍了淮河流域的自然和水环境背景,然后分析了干流区水质的时空变化趋势及其原因。最后对淮河治理存在的问题进行了总结。从总体上看,淮河流域的水污染仍十分严重,防污治污工作任重而道远。     

麦饭石对NOx的吸附

研究了麦饭石在不同预处理方法、粒径、活化温度、NOx初始质量浓度和吸附时间等条件下对NOx的吸附性能。实验结果显示：粒径为0.18mm的麦饭石经过400～600℃活化1h后,NOx吸附率大于99%,饱和吸附量大于6.3m g/g。经4次重复活化后,麦饭石对NOx的吸附效果仍然很好,可作为处理含NOx废气的吸附剂。     

不同森林土壤微生物群落对Biolog-GN板碳源的利用

应用Biolog方法研究了不同森林恢复类型（人工恢复的湿地松林、杉木林、油茶林和自然恢复的天然次生林）土壤微生物群落对Biolog-GN板不同类型碳源的利用情况,结果表明,自然恢复的天然次生林土壤微生物群落的碳源代谢能力比3种人工林强,其次是油茶林.4种森林类型土壤微生物群落比较偏好、利用率较高的3类碳源是糖类、羧酸类和氨基酸类.对4类森林恢复类型土壤微生物群落具有分异作用的主要碳源类型亦为糖类、羧酸类和氨基酸类,这3类碳源是研究森林恢复后导致土壤微生物群落变化的敏感碳源.     

活性炭烟气脱硫技术研究新进展

研制了新型活性炭脱硫剂－脱硫活性碳纤维。研究表明，脱硫活性碳纤维由于含碳量高、比表面积大、微孔丰富、孔径分布窄、有较多适于吸附ＳＯ２的表面官能团，因而吸附能力及吸附、脱附速度显著大于普通活性炭。在相同工艺条件下，脱硫活性碳纤维吸附容量为粒状疾性炭的４－５倍，空速粒达活性炭的１０倍。采用活性碳纤维脱硫可比普通活性碳脱硫剂用量成倍减少。另外，由于活性碳纤维阻力小，系统能耗可显著降低。活性碳烟气脱硫采用