酸性尿素水溶液处理导弹氧化剂废水中氮氧化物

采用理论分析和实验两种方法对酸性尿素水溶液处理导弹氧化剂废水中NOx进行了研究.讨论了NO2的转化率与尿素浓度的关系.实验证明,该方法快速高效,反应的适宜温度为30 C,用7%的尿素水溶液处理含NO2 9 41 9.8 mg/m3的废水,10 s的去除率可达99.5%.     

Sensitivity of Ozone Production to the Nmhc Composition,Aerosol Back-Scattering and High Chimney Emission

Abstract

In this paper, three sensitivity studies are designed to analyze the effect of the NMHC (Non-Methane HydroCarbon) composition, the aerosol back-scattering and the high chimney NO _x emission to the photochemical prodution of ozone by using a one-dimensional photochemistry-diffusion model under a favourable meteorological condition. Measurements of the NMHC composition in Taipei indicated that the percentage of iso-butene, cis-2-butene, trans-2-butene and benzene in a unit volume was much higher than of those observed in other major cities. the high ratio of benzene was directly linked to its high percentage in gasoline. As to the unusually high amount of iso-butene, cis-2-butene and trans-2-butene, more researches are needed to identify their source. Concerns are raised as to how productive is NMHC composition is to the photochemical production of the surface ozone. A rough estimate shows that the total reactivity of the Taipei NMHC composition is about 1.21 × 10^?9 cm³ s^?1 which is 1.6 times that of the Los Angeles (LA) NMHC composition, while the simulated noon peak will be different by 28 ppbv, i.e. 18% more than that simulated with a LA composition.

Meanwhile, high aerosol loading is a serious problem in Taipei. the attenuation of the UV radiation by aerosols cannot be ignored. A numerical simulation shows that the noon ozone level will decrease from 178 to 141ppbv, i. e. about 21% reduction, with deterioration of the visual range from 85 to 5 km.

In the southern Taiwan, industry parks are mixed with the populated Kaohsiung city, hence the large emission of NO _x from high chimneys cannot be ignored. in this study, NO _x is assumed to be emitted in the layer between 235–460 m high with an emission rate of 0.05 or 0.145 ppbv/sec. the results show that the NO _x emitted from the elevated stack lead to a considerable reduction of surface ozone. Such conclusion is obtained due to the fact that a one-dimensional model is used in this paper. Whereas, if a three-dimensional regional model was used, then a higher productivity of ozone downstream would be simulated.     

低温等离子体技术及其在柴油机排气处理中的应用

概述了等离子体特点及分类 ,介绍了低温等离子体的产生及其净化柴油机排气的应用进展 ,分析了低温等离子体技术有效处理柴油机排气的机理 ,阐述了未来低温等离子体处理柴油机排气的主要方向与应用前景。     

Aerobic thermophilic bacteria enhance biogas production

The enhancing effect of aerobic thermophilic (AT) bacteria on the production of biogas from anaerobically digested sewage sludge (methanogenic sludge) was investigated. Sewage sludge (5%, w/w) was incubated at 65°C with shaking for a few months to prepare the AT seed sludge. AT sludge was prepared by incubation of the AT seed sludge (5%, v/v) and sewage sludge (5%, w/w) at 65°C with shaking. The addition of this AT sludge (1.2% ± 0.5% of total volatile solids) to methanogenic sludge enhanced the production of biogas. The optimum volume of the addition and the pretreatment temperature of the AT sludge for optimum biogas production were 5% (v/v) and 65°C. Batch-fed anaerobic digestion was covered with the addition of various AT sludges. The AT sludge prepared with the AT seed sludge improved the biogas production by 2.2 times relative to that from the sewage sludge addition. The addition of sludge without AT seed sludge weakly enhanced biogas production. An aerobic thermophilic bacterium (strain AT1) was isolated from the AT seed sludge. Strain AT1 grew well in a synthetic medium. The production of biogas from the anaerobic digestion of sewage sludge was improved by the addition of 5% (v/v) AT1 bacterial culture compared with that from the sewage sludge addition. The addition of AT1 culture reduced the volatile solids by 21%, which was higher than the 12.6% achieved with the sewage sludge addition. The AT1 bacterial culture enhanced the biogas production more than the AT seed sludge. The phylogenetic analysis of the 16x87228162v203/xxlarge8201.gif" alt="thinsp" align="MIDDLE" BORDER="0">S rRNA gene revealed that strain AT1 is closely related to Geobacillus thermodenitrificans (100% sequence similarity). The improvement in the production of biogas with the AT sludge could be caused by thermophilic bacterial activity in the AT sludge.     

超细化煤粉低温燃烧的NOx、SO2生成特性研究

在实验室水平管式电炉上，在较低温升速率和低温燃烧（３００℃－５００℃）的条件下，分别对经过超细粉碎的合山高硫煤和晋城煤４种不同粒度煤样的燃料ＮＯｘ、有机硫分的ＳＯ２和ＣＯ生成特性进行了试验研究，分析了以ＣＯ为主的还原性气氛在超细化煤粉燃烧过程中对固氮和固硫所产生的影响。     

中国生物质燃烧排放SO2、NOx量的估算

根据各地区生物质燃料消耗状况和SO2、NOx排放因子，估算了20世纪90年代中国生物质能源利用过程中的SO2、NOx排放量，并给出了分省区，分生物质燃料类型的排放清单，研究表明，中国生物质燃料消耗及其排放的SO2，NOx量分别从1991年的38.1万t和54.9万下降为1999年的33.2万t和45.3万t，在地区，燃料类型上分布不平衡；SO2和NOx排放量均较大的包括山东，江苏、河北，内蒙古，湖北等，其中，内蒙古SO2排放量最大而山东省NOx排放量最 ；秸杆是SO2和NOx排放的最主要来源，薪柴次之；牲畜粪便对SO2贡献率接近30%，而对NOx贡献率仅3%-4%。     

利用焦炭吸附进行燃煤烟气脱硫脱氮技术的研究

介绍一种干法烟气脱硫脱氮工艺方法 ,利用一种非常容易获得炭质吸附材料经过简单的工艺处理后 ,达到燃煤烟气脱硫脱氮效果 ,整个过程不产生二次污染     

Hydrolytic and enzymatic degradation of poly(γ-glutamic acid) hydrogels and their application in slow-release systems for proteins

The hydrolytic and enzymatic degradation of newly developed hydrogels, produced by cross-linking purified poly(x110q46410844/xxlarge947.gif" alt="gamma" align="MIDDLE" BORDER="0">-glutamic acid) (x110q46410844/xxlarge947.gif" alt="gamma" align="MIDDLE" BORDER="0">PGA) with dihaloalkane compounds, was studied and is reported in this paper. Analysis of hydrolysis of the hydrogel as a function of pH indicated that the hydrolysis occurred slowly at neutral pH, but fast in both acidic and alkaline solutions, while the polymer could be hydrolyzed rapidly only in acidic solutions. The ester bonds were more sensitive to hydrolysis than peptide bonds. The biodegradability of the hydrogel and polymer was further confirmed when enzymatic degradation was studied by three enzymes (cathepsin B, pronase E, and trypsin), which were able to cleave both ester and peptide bonds gradually. A slow-release system for porcine somatotropin (pST) formed by using the hydrogel as matrix to entrap the hormone was evaluatedin vitro andin vivo. Results demonstrated that the hydrogel was able to release the hormone for a period of 20–30 days and indicated its potential application in slow-release systems for bioactive materials, especially macromolecules, such as peptides and proteins.     

陶瓷窑炉内NOx生成的三维数值模拟

借助计算流体力学(CFD)FLUENT软件对NOx在陶瓷烧成过程中的生成机理进行了研究,并探讨了影响NOx生成的因素,为治理及减少NOx排放提供相关的参考.研究发现,随着升温速度的增大,窑内温度均匀性变差,易形成局部高温点(区),从而导致NOx生成速度的增大;燃料所产生的中间产物NH3或HCN浓度在远离烧嘴和料垛区域中较小,总NO和燃料型NO浓度却较大.不过,无论中间产物为NH3还是HCN,都不能减少有害气体的生成.     

Cu/海泡石催化剂上NOx催化还原的研究

以天然海泡石为原料,经酸改性后作载体.采用浸渍法制成了用于NOx由CO还原的Cu基催化剂.在稀薄燃烧条件下,考察了它对汽车尾气中NOx的还原性能.实验结果表明,Cu/海泡石催化剂在富氧条件下具有良好的耐湿热稳定性和催化活性,当转化率达到90%时,反应温度＜400 ℃.当掺入稀土元素Ce和Sm后,由于与活性组分Cu之间的协同效应,催化剂的抗氧能力进一步提高了.