CO还原脱硝反应锌铜双金属有机骨架催化剂的制备

采用离子交换法制备锌铜双金属有机骨架(Zna/HKUST-1,a=1/24,1/12,1/6,1/3,a为Zn与Cu的摩尔比),用于催化CO还原脱硝反应。采用XRD,SEM,FTIR,H2-TPR,BET等方法对Zna/HKUST-1进行了表征。表征结果表明:Zna/HKUST-1中有明显的Zn—O键和铜基金属有机骨架(HKUST-1)的结构,证明Zn成功进入了HKUST-1中;但随a的不同,Zna/HKUST-1的形貌、大小及比表面积出现了差异。实验结果表明,Zna/HKUST-1(a=1/24)对CO还原脱硝反应的催化活性最高,可在230℃达到NO转化率100%。     

检测污水中氨氮大于总氮原因简析及改善

通常情况下同一个水样中的氨氮值应该小于总氮值,但是在实际的检测工作中常常遇到同一个水样氨氮值大于总氮的情况,基于数据与理论值的差异,本文探讨了出现这种情况的主要原因是当水样中氨氮占据总氮的绝大部分比例时,碱性过硫酸钾消解条件下,总氮中的氨氮会以氨气的形式逸散在气相中极易造成损失,并通过对比分析了改进密封性对于实验数据的改善情况。     

Numerical modelling for effect of water curtain in mitigating toxic gas release

Hydrogen fluoride and ammonia are widely used in chemical industries. Both substances are hazardous and frequently a source of leakage accidents. Since a hydrogen fluoride release accident occurred in Gumi, S. Korea (2012), the Korea Occupational Safety and Health Agency (KOSHA) has emphasized that special attention and management are needed with respect to toxic substances. For post-release mitigation, a water curtain is known as one of the most effective and economical systems. In this study, a computational fluid dynamics (CFD) program was used to identify the effect of using a water curtain as a mitigation system for toxic substances that leak out from industrial facilities. Simulations were conducted to analyze how effectively a water curtain could mitigate the dispersion of toxic substances. To verify the simulation's accuracy, the INERIS Ammonia dispersion experiment and Goldfish experiment were simulated and compared. Various water curtains were applied to the simulated field experiment to confirm the mitigation factors with toxic substances. The results show that the simulations and experiments are consistent and that the dispersion of toxic substances can be mitigated by water curtains in certain circumstances.     

无黏结剂ZSM-5分子筛的制备及其对甲苯的吸附性能

以硅溶胶为黏结剂,将粗孔硅胶、聚乙二醇、拟薄水铝石、ZSM-5晶种导向剂捏条成型,采用干胶转化法制备得到了无黏结剂ZSM-5分子筛。XRD和SEM等表征方法的结果显示,采用干胶转化法制备得到的ZSM-5分子筛的相对结晶度较高,具有200nm左右的小晶粒构成的自支撑结构。采用无黏结剂ZSM-5分子筛吸附剂进行甲苯吸附-脱附实验,该吸附剂表现出良好的吸附性能,对甲苯的脱附性能优于活性炭。     

水合改性对钙基吸收剂循环捕集CO2的影响

在钙基吸收剂捕集CO2的过程中,吸收剂转化率会随着循环次数的增加而迅速降低。钙基吸收剂的水合改性作为改善吸收剂循环转化率的主要方法之一受到了国内外学者的广泛关注。总结了目前国内外研究者对不同的吸收剂、循环捕集条件下的水合改性方法的研究成果。结果表明,在循环过程中的不同阶段对吸收剂进行水合处理后得到的效果不同。其中,在碳酸化阶段、煅烧阶段、循环捕集前预处理以及煅烧后对吸收剂水合改性．吸收剂捕集CO2的能力均得到了改善;碳酸化反应后对吸收剂进行水合处理是否对循环吸收有利还存在争议。目前,利用水合改性的方法提高钙基吸收剂循环捕集CO2能力的机理还存在争议,且水合改性后的吸收剂机械性能差以及此方法能耗高的问题尚待解决。     

Monitoring H2S air pollution caused by the industrial exploitation of geothermal energy: The pitfall of using lichens as bioindicators

This study showed that NH₃ emitted from geothermal power plants affects the surrounding epiphytic lichen vegetation and diversity, confounding the interpretation of lichen diversity counts in terms of air pollution by H₂S. The presence of nitrophytic lichen species around geothermal installations, determined by NH₃, caused relatively high diversity values that were not related with the levels of air pollution by H₂S. It is recommended that in the presence of NH₃ emission, nitrophytic species are excluded from the calculation of lichen diversity values.     

CeO2-CoO／ACF低温SCR烟气脱氮性能的研究

活性炭纤维（ACF）经硝酸处理后采用浸渍法制备了CeO2-CoO／ACF复合催化剂,测试了其在以氨气为还原剂的低温SCR过程中的催化活性,同时研究了金属氧化物浸渍顺序及负载量、催化剂煅烧温度、空速比（SV）、NH,／NO（摩尔比）、O2含量等因素对NO转化效率的影响。研究发现,负载量为10％的CeO2-CoO／ACF复合催化剂经煅烧后在120—240℃时具有很高的催化活性,并且在N0初始浓度为1000mg／m3、空速比（SV）为6000h～、NH3／NO为1．05、O：体积分数在3．0％时具有较高的NO转化效率。     

Ammonia volatilization loss from surface applied livestock manure

Ammonia (NH₃) emission from livestock manures used in agriculture reduces N uptake by crops and negatively impacts air quality. This laboratory study was conducted to evaluate NH₃emission from different livestock manures applied to two soils: Candler fins sand (CFS; light-textured soil, pH 6.8 and field capacity soil water content of 70 g kg^{? 1}) from Lake Alfred, Florida and Ogeechee loamy sand (OLS; medium-textured soil, pH 5.2 and field capacity soil water content of 140 g kg^{? 1}) from Savannah, Georgia. Poultry litter (PL) collected from a poultry farm near Douglas, Georgia, and fresh solid separate of swine manure (SM) collected from a farm near Clinton, North Carolina were used. Each of the soil was weighed in 100 g sub samples and amended with either PL or SM at rates equivalent to either 0, 2.24, 5.60, 11.20, or 22.40 Mg ha^{? 1} in 1L Mason jars and incubated in the laboratory at field capacity soil water content for 19 days to monitor NH₃ volatilization. Results indicated a greater NH₃ loss from soils amended with SM compared to that with PL. The cumulative NH₃volatilization loss over 19 days ranged from 4 to 27% and 14 to 32% of total N applied as PL and SM, respectively. Volatilization of NH₃ was greater from light-textured CFS than that from medium-textured OLS. Volatilization loss increased with increasing rates of manure application. Ammonia volatilization was lower at night time than that during the day time. Differences in major factors such as soil water content, temperature, soil type and live stock manure type influenced the diurnal variation in volatilization loss of NH₃ from soils. A significant portion (> 50%) of cumulative NH₃ emission over 19 d occurred during the first 5–7 d following the application of livestock manures. Results of this study demonstrate that application of low rates of livestock manure (≤ 5.60 Mg ha^{? 1}) is recommended to minimize NH₃ emissions.     

基于DEA的中国农地非农化效率及其变化

基于DEA和Malmquist TFP指数模型方法研究分析2000～2008年我国省域和区域层面农地非农化效率及其变化,为优化土地利用提供参考。研究结果表明：（1）省域层面各项平均效率水平一般,超过80%的省份农地非农化综合效率未达到有效状态;（2）农地非农化效率总体呈现东部地区>东北地区>中部地区>西部地区的状态,区域差距呈现缩小趋势;（3）农地非农化平均综合效率的提升主要源于纯技术效率的贡献,而生产效率的明显改善得益于技术进步;（4）东部和东北地区农地非农化综合效率有所下降,中西部地区综合效率呈现上升趋势,西部地区上升显著。通过研究发现：现阶段我国农地非农化存在要素资源的利用不充分现象,效率提升潜力较大;西部地区农地非农化规模集聚能力与其他地区差距较大;东部地区存在农地非农化效率损失;虽然中西部地区农地非地化效率变化提升明显,但能否成为农地非农化指标增加的依据还值得进一步探讨     

农地非农化中不同利益主体博弈行为分析

随着我国社会经济的发展,城市的加剧扩张和建设用地需求的不断增长而带来的农地非农化在近年来表现得尤为突出,已经严重影响着我国的粮食安全和生态安全.因此,从决策主体行为出发,研究农地非农化问题,对于我国城市化的正常推进以及农地的有效保护具有重要的现实意义.本文从博弈论的角度探讨农地非农化过程中相关利益主体的行为倾向和博弈关系.研究结果表明:(1)中央政府应该加大给予地方政府和农民进行耕地保护的奖励以及提高违规的惩罚力度,抑制农地非农化的速度,遏制违法占用,提高土地的利用率,减少耕地资源的闲置和浪费;(2)中央政府和地方政府应完善相关政策,缩小城乡土地价格差异,提高征地补偿标准,逐步建立公正的补偿机制和科学合理的补偿标准;(3)地方政府应进行土地利用制度和模式的创新,注重力拓土地后备资源,盘活存量资源,减少建设占用农地,不仅能有效地解决经济建设和耕地保护的两难困境,而且能有效地保护生态环境,实现土地资源的可持续合理利用.