ORP控制在硫化物生物氧化成单质硫过程中的应用

试验采用气升式反应器,接种实验室自行培养的排硫硫杆菌种,在进水pH值为7.0±0.2,温度控制在30±2℃条件下,研究了以ORP为控制参数在硫化物生物氧化成单质硫过程中的应用,并考察了pH和污泥硫负荷对ORP及硫化物生物氧化的影响.结果表明,硫化物去除率和硫酸根生成率均随ORP的降低而下降,不同容积负荷下,控制合适的ORP均可得到单质硫的最大生成率;当ORP为-380～340 mV,pH为7.85～8.63,污泥硫负荷为8.4 kg S/(kg MLSS·d)时,反应器运行状况良好.     

硫高温腐蚀及腐蚀产物氧化自燃性的研究

随着炼制原油硫含量的增加,炼油装置的硫腐蚀问题也日益严重.针对硫高温腐蚀状况,用差热-热重分析仪研究硫与Fe(OH)3、Fe2O3和Fe3O4发生硫化腐蚀反应的初始温度,并采用X射线衍射仪鉴定了360 ℃高温无氧条件下硫化腐蚀产物的组成.结果表明,硫与Fe(OH)3、Fe2O3和Fe3O4发生硫化反应的初始温度分别为287.67 ℃、233.34℃和308.47 ℃;高温硫化腐蚀产物主要是FeS2.对硫化产物FeS2进行氧化反应,氧化升温曲线和耗氧曲线表明,硫化腐蚀产物FeS2具有很高的氧化自燃性,在一定条件下能引发油品火灾和爆炸等事故.     

Aromatization of waste polyolefin pyrolysate over H-ZSM-5 zeolite-supported gallium oxide catalysts

H-ZSM-5 zeolite-supported gallium oxides were studied as aromatization catalysts for polyolefin pyrolysate. The catalysts were prepared by a conventional physical mixing method with a gallium content of 1.0 and 4.5 wt% and were reduced in flowing hydrogen at 585°C. To test their activity, a polyolefin sample was pyrolyzed and passed over a heated catalyst layer; the product was analyzed by gas chromatography/mass spectrometry. A continuous-flow fixed-bed reactor was used for aromatization of a model gas of polyolefin pyrolysate. For chlorine-free sources at 450°C, the catalyst with only 1.0 wt% gallium exhibited activity comparable to a gallium silicate catalyst. For chlorine-contaminated sources, the catalyst with 4.5 wt% gallium sustained catalytic activity for long periods. From the activity test results, it was found that zeolite-supported gallium catalysts prepared by the physical mixing method are suitable for converting polyolefin into aromatic hydrocarbons.     

煤和聚丙烯腈炭化过程中负载铁原子在表面与体相间的质量迁移

采用ＸＰＳ和Ａｒ＾＋离子刻蚀技术，研究了炭化过程中铁原子在煤和聚丙烯腈表面和体相间的质量分布规律。结果发现，随炭化进行铁原子由表面向体相迁移和富集，炭化温度升高，迁移和富集增加，表面浓度逐渐降低，以致铁原子沿粒子径向呈浓度梯度分布。     

钢铁烧结行业脱硫石膏综合利用前景

分析我国钢铁行业烧结烟气脱硫现状,论述了脱硫石膏的特性,指出了脱硫石膏的综合利用价值,其社会效益和经济效益是巨大的.     

城市煤气网管系统的安全维护及运行

煤气作为一种二次能源,是城市中使用的主要能源之一.燃气行业的生产、输送、使用过程,从某种角度来讲是高危的作业过程.煤气网管系统的施工和维护过程中充满了种种困难和危险,造成了许多重大损失,其主要原因是缺乏有效的组织引导和规范的安全措施.本文着重分析了煤气网管系统发生泄露事故的原因,提出了煤气网管系统的运行和维护过程中应当遵循的安全事项和采取的安全措施,为煤气网管系统的运行和维护工作提供了理论依据.     

石油石化行业急性中毒事故的现场抢救

石油石化行业工艺复杂,存在的有害因素种类繁多,一旦发生急性中毒其涉及面广、影响大,有时可造成严重危害。文章较为详细地介绍了该行业存在的主要有毒物质以及发生急性中毒事故的必要条件和特点,阐述了有毒物质侵入人体的途径主要为直接接触或通过呼吸,最后针对一般情况、吸入性中毒、直接接触造成危害的情况介绍了相应的现场急救处理措施。     

HP6890色谱柱用于环境空气中微量恶臭硫化物的检测

利用HP6890型气相色谱仪进行环境空气中微量恶臭硫化物分析,实验结果表明:分离效果、峰形都很好,实验采用4种柱箱初始温度及升温程序,分别由初始温度70℃升温至90℃、120℃、130℃及由初始温度150℃,最后升温至190℃,相应分析一个样品的时间依次为:130.515min、63.419min、56.359min及11.116min,样品分析时间大大缩短,可提高分析效率。     

Microbially Mediated Redox Cycling at the Oxic–Anoxic Boundary in Sediments: Comparison of Animal and Plants Habitats

Microorganisms are responsible for the bulk of transformations that occur in surficial sediments. They are most active at redox boundaries where they can benefit from access to various oxidants and reductants generated during redox cycling events. To illustrate the dynamics of microbially mediated processes, especially those involving sulfur and metal cycles, processes were compared in habitats either bioturbated by a capitellid worm or inhabited by a salt marsh grass. The presence of macrofauna and macroflora greatly altered the three-dimensional array of redox gradients in sediments, but the type and form of reductants and oxidants provided varied greatly; clastic sedimentary infauna subducted solid phase organic material and iron oxides, whereas plant roots released dissolved organic matter and oxygen. These differences resulted in a bioturbated system that exhibited a rapid sulfur cycle (residence time of minutes), but a slower iron cycle (days), whereas vegetation caused a slow sulfur cycle and rapid iron cycle. Alteration of sediments by higher life forms also greatly affected the composition and relative abundances of sedimentary bacteria, even on short time scales. Although redox cycling at interfaces can be somewhat predictable, variations in response to biological and physical perturbations demonstrated wide differences in the dynamics of redox-mediated processes.     

职业性有机溶剂中毒特点及防治对策探讨

随着有机溶剂应用的日益广泛，职业性有机溶剂中毒事件频繁发生。通过分析近年来的职业性有机溶剂中毒事故，探讨了职业性有机溶剂中毒的特点，并对如何有效预防职业性有机溶剂中毒提出了初步的建议，如可以通过改革工艺，加强通风排毒等措施来预防职业性有机溶剂中毒。