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用液相催化氧化法对低浓度H2S净化进行实验研究.实验结果表明,对H2S浓度在1500-2500mg/m3之间,氧含量为5%的H2S尾气,Fe+、Zn2+和Mn2+在液相中对H2S具有催化氧化作用,其催化性能大小顺序为Fe2+>Zn2+>Mn2+,且Fe2+催化性能远远大于其他两种离子;用Fe2+作催化剂,溶液的净化效率可达99%以上,且硫容量也较大,对低浓度H2S的净化相当有利. 相似文献
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在填料吸收塔中考察了Na2CO3溶液吸收高浓度H2S气体的气液传质特性。通过测量填料塔进出口气体中H2S浓度计算了Na2CO3溶液吸收高浓度H2S气体的总体积传质系数(KGa),并研究了进气流速、吸收液流量、吸收温度和吸收液浓度对KGa的影响。结果表明,KGa随Na2CO3浓度、吸收液流量的增加而增加,随吸收温度、进气流速的升高而降低;在高浓度H2S吸收过程中液相传质阻力不能忽略。 相似文献
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PH3液相催化氧化净化研究 总被引:2,自引:0,他引:2
以Mn2 和Pd2 为催化剂的吸收液对含低浓度PH3的混合气进行了液相催化氧化净化研究.考察了催化剂配比、混合气中O2浓度、PH3初始浓度、反应温度、气体流量和吸收液pH与PH3净化效率的关系.结果表明,催化剂中Pd2 与Mn2 的质量比为1:4时可获得较佳的净化效果;随着混合气中O2浓度的增加,吸收液对PH3的净化效率有所提高;在20~75℃内,低温对PH3净化有利,较适宜的反应温度为20℃;较低的PH3初始浓度和低气体流量均有利于PH3的净化;较高的pH有利于吸收液中催化剂催化效能的发挥.吸收液对PH3的净化效率可达100%,但因吸收液中的金属离子易与催化氧化PH3产生的PO3-4形成沉淀,使金属离子脱离液相催化氧化系统,吸收液失效较快. 相似文献
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在柠檬酸盐吸收—解吸脱硫技术中,完成循环吸收过程的吸收液由于烟气杂质催化和高温解吸变成了含低二氧化硫浓度、中高硫酸根浓度、多种有机酸共存的柠檬酸盐解吸贫液,造成吸收效率下降、SO2平衡容量严重降低,必须进行溶液净化,特别是净化硫酸根。针对这一问题,实验室采用低温结晶法净化柠檬酸盐脱硫解吸贫液模拟液,通过对溶液中硫酸根浓度分析,研究了不同反应时间、温度、初始硫酸根浓度、柠檬酸根总浓度和溶液p H对硫酸根去除效率的影响。结果表明,硫酸根去除率与冷冻温度和溶液p H有关。在柠檬酸根总浓度1.5 mol/L,初始硫酸根浓度40 g/L,冷冻温度3℃,p H 4.5的条件下,可将硫酸根净化至16.9 g/L。 相似文献
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开发了一种用含Cu2 的溶液吸收H2S,并用Cu2 自氧化CuS制取硫磺的新工艺,Cu2 的还原产物CuCl2-由空气氧化再生,实现循环.考察了Cu2 浓度与净化效率的关系,研究了Cu2 、H 、助剂N的浓度和温度对Cu2 氧化CuS效率的影响及H 、助剂N的浓度、空塔气速和温度对Cu2 空气氧化再生效率的影响.结果表明,该技术对H2S废气净化效率100%,Cu2 氧化CuS及Cu2 空气氧化再生条件温和、效果好,终产物硫磺纯度高. 相似文献
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Alfred Eisner Jacob Tadmor 《Journal of the Air & Waste Management Association (1995)》2013,63(4):400-401
A number of key projects in the Environmental Protection Agency (EPA) particulate R&;D program having applicability to industry are presented. For electrostatic precipitators (ESP) there is presented the result of work on large diameter discharge electrodes which provide a decrease in penetration of up to a factor of 4 when compared to conventional small diameter electrodes. Also discussed is the multistage ESP which provides a collection efficiency that would require a collecting plate area 4 or 5 times larger with conventional ESP technology. The E-SOX technology makes use of the multistage concept to free up space in the ESP for SO2 removals of up to 90%. Electrostatically augmented fabric filtration provides a reduction in pressure drop of about 5 0% as compared to conventional fabric filtration. Wind tunnel modeling of windbreaks for material storage piles indicates a potential for providing engineering design data that would allow significant emission reduction caused by wind erosion 相似文献
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《国际环境与污染杂志》2011,10(2):304-314
This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies). 相似文献
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Janusz A. Pudykiewicz Anna S. Koziol 《Atmospheric environment (Oxford, England : 1994)》1998,32(24):5541
The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing. 相似文献
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Árpád Ambrus 《Journal of environmental science and health. Part. B》2013,48(3):435-442
Abstract A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits. 相似文献
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结合扬中生态环境的基本情况和存在的不足,进行了具体分析,对扬中未来生态建设的发展方向提出了建议及实施措施。 相似文献
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在实施ISO/IEC17025:1999标准《检测和校准实验室能力的通用要求》过程中,通过实验室质量管理体系内部审核的实践与系统分析,识别出内部审核实施阶段的关键环节,提出召开首次会议、收集审核证据、确定审核发现和召开末次会议的技术方法,对提高内部审核的质量和有效性、获得可靠的审核结论具有重要意义。 相似文献
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介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠 相似文献
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考察了不同有机改性硅对微囊藻毒素LR(mLR)和LA(mLA)的等温吸附行为。结果表明,有机改性硅可有效吸附去除水体中<0.1×10-6(质量分数)的微囊藻毒素,并且吸附去除效果随表面改性官能团中碳原子数量的增加而增加;相同条件下,有机改性硅在微囊藻毒素异构体之间存在着一定的吸附选择性。 相似文献
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以松木木屑为原料,在自制的小型流化床上,开展了生物质热裂解温度、生物质粒径和进料速率对生物油产率的影响实验研究.结果表明,在热裂解温度分别为450、475、500、525和550℃条件下,当热裂解温度为500℃时,生物油产率最高,平均产率达到53.33%(质量百分比).反应温度越高,炭产量越低,不可冷凝气体产量越高,气体发热值越高;粒径<1 mm的生物质其粒径对生物油产率影响不大;生物质进料速率增加时,生物油产率增加.本研究为生物能的利用提供了新的途径. 相似文献