室外空气污染对室内空气质量的影响研究

利用数值模拟方法,研究了单个建筑物外存在点污染源时室外空气污染对室内空气质量的影响.首先利用点污染源时单个建筑物周围污染物扩散的风洞实验验证了计算模型和方法的正确性,再利用自然通风的风洞实验,计算了不同污染源位置和建筑物进风口时的室内外速度场和污染物浓度场.结果表明:速度场的计算结果与风洞实验结果基本吻合,无量纲通风量的计算值略小于实验值;建筑物迎风面回流区上方的气流进入室内;当点污染源位于建筑物前的距离和建筑物高度之比约等于1时,污染源在地面处的室内污染物浓度要小于源在建筑物高度一半处的;建筑物进风口的挡风板对室内污染物浓度的影响不大;根据壁面上污染物浓度的分布来改变进风口位置,是减少室内空气受室外污染影响的有效方法.      

Major and trace elements in paddy soil contaminated by Pb–Zn mining: a case study of Kočani Field,Macedonia

The objective of this study was to assess the bulk chemical composition as well as the extent and severity of heavy metal contamination in the paddy soil of Kočani Field (eastern Macedonia). The results revealed that the paddy soil of the western part of Kočani Field is severely contaminated with Pb, Zn, As and Cd in the vicinity of the Zletovska River due to irrigation with riverine water that is severely affected by acid mine and tailing effluents from the Pb–Zn mine in Zletovo. The detected total concentrations of these metals are far above the threshold values considered to be phytotoxically excessive for surface soil. The paddy soil in the vicinity of the Zletovska River was also found to exhibit elevated levels of Ba, Th, U, V, W, Mo, Cu, Sb, Bi, Ag, Au, Hg and Tl, with concentrations above their generally accepted median concentration values obtained during this study. A correlation matrix revealed that the Mn and Fe oxides/hydroxides are the most important carrier phase for several trace elements, with the exception of rare earth elements (REEs). These also represent a major sink for the observed heavy metal pollution of the soil. REEs are mostly associated with two phases: light (L)REEs are bound to K-Al, while heavy (H)REEs are bound to Mg-bearing minerals. Although there is no direct evidence of a health risk, the paddy soil in the vicinity of Zletovska River needs further investigation and an assessment should be made of its suitability for agricultural use, particularly in view of the highly elevated concentrations of Pb, Zn, As and Cd.     

果尔对水稻土中厌氧细菌的影响

探讨了各种浓度的果尔对水稻土中厌氧细菌群的影响,实验表明,低于或等于田间正常施药量的果尔,在１周内对各类氧细菌的生长具有刺激作用,随着施药后时间的延长,刺激作用逐渐消失;高于田间正常施药量的果尔,在１周内对各类厌氧细菌的生长具有明显的抑制作用,随着施药后时间的延长,果尔的降解产物能促进各类厌氧细菌的生长。     

基于CAN总线的智能污水处理集成系统

介绍了利用可编程控制器(PLC)、仪表、CAN总线模块作为前沿智能节点组成的污水处理系统。实现了现场设备和中控微机之间的实时数据传送和分散控制。     

电除尘器气流分布的等效阻力法模拟计算

在此提出了一种电除尘器内气流分布的简易计算模拟方法 ,其核心就是把气流分布板作为均匀的透气板看待 ,使多孔板阻力与均匀透气板阻力等效 ,从而大幅度减少网格数量和计算时间。简化计算的数据与模型试验的测试数据相吻合 ,表明该简易计算模拟方法完全可以取代现行的模型试验法 ,这对计算模拟的普及、电除尘器成本的降低、设计的优化等都具有重要意义     

二段往复炉排焚烧炉炉拱的优化辅助设计

为实现二段往复炉排焚烧炉炉拱的优化设计 ,运用PHOENICS软件进行炉内流场的模拟 ,研究炉拱形状和尺寸对流场的影响。通过模拟发现 ,后拱后移可以避免压火现象 ,保证炉膛空间良好的火焰充满度 ,但存在最佳后移尺度 ,以同时保证喉口位置烟气湍流效果强烈 ,充分发挥炉膛后拱和前拱的辐射及对流传热的效果。根据炉内气流湍动情况以及风速的范围 ,确定在原设计基础上将后拱后移 0 5m为最佳炉膛尺寸     

采油污水生物处理技术

采油污水是石油工业中的重点污染源之一。本文论述了采油污水生物处理的难度和技术可行性 ,总结了国内外近年来采油污水生物处理技术的现状及研究进展。     

膜蒸馏用于气田采出水的深度处理

采用自制聚丙烯中空纤维疏水膜,开展了内压式真空膜蒸馏处理某气田采出水的实验研究,考察了膜通量、脱盐率、产水电导率及产水水质等随运行时间的变化,针对实验后期出现的膜污染情况对膜蒸馏浓水除硬后进行二段膜蒸馏,再对出水进一步做催化臭氧氧化处理。实验结果表明：105 h后,废水中各离子浓度随着废水的浓缩而急剧升高,同时废水的高硬度造成膜堵塞,产生膜污染;除硬后去除了膜结垢污染,改善了膜疏水性能,膜通量恢复到初始膜通量的73%;膜蒸馏出水经催化臭氧氧化处理后,出水COD、TOC和ρ（NH₄⁺-N）分别为49 mg/L、6.5 mg/L和11.0 mg/L,满足回用要求。     

轴向单缝偏心药柱爆破效应模型试验研究

为了探究轴向单缝偏心药柱在掏槽爆破中爆炸应力波传播规律和裂纹扩展情况,采用水泥砂浆模型试块开展模型爆破试验,采用超动态应变测试系统对爆炸应力场进行测量。结果表明:在相同爆心距下,背对切缝侧A测点仅为正对切缝侧B测点峰值应力的73.82%;一定角度范围内,峰值应力随偏转角度的增大而减小,偏转角度为0°时峰值应力最大,偏转角度为60°处峰值应力是偏转角度为30°处的74.39%,峰值应力在0°到60°范围内最大衰减达到32.74%;正对切缝方向产生一条贯通炮孔的主裂纹,裂纹发育优于其他方向,且切缝方向没有明显的细小裂纹,这表明轴向单缝偏心药柱具有良好的定向断裂能力。     

Numerical study of medium to large scale BLEVE for blast wave prediction

So far, the prediction of blast wave generated from the Boiling Liquid Expanding Vapour Explosion (BLEVE) has been already broadly investigated. However, only a few validations of these blast wave prediction models have been made, and some well-established methods are available to predict BLEVE overpressure in the open space only. This paper presents numerical study on the estimation of the near-field and far-field blast waves from BLEVEs. The scale effect is taken into account by conducting two different scale BLEVE simulations. The expansion of pressurized vapour and evaporation of liquid in BLEVE are both modelled by using CFD method. Two approaches are proposed to determine the initial pressure of BLEVE source. The vapour evaporation and liquid flashing are simulated separately in these two approaches. Satisfactory agreement between the CFD simulation results and experimental data is achieved. With the validated CFD model, the results predicted by the proposed approaches can be used to predict explosion loads for better assessment of explosion effects on structures.