斜板沉降器油水分离试验

为了满足油田或炼油厂含油污水处理达标排放和水资源的再利用,对斜板沉降器的油水分离机理进行了研究。通过理论推导得出上浮速度的关联式,结合试验分别对其结构参数和操作参数进行优化,找到板长、板间距、倾角及板间流速的最佳值。结果表明:优化后的斜板沉降器有较好的油水分离效果。     

烟花爆竹工程外部最小允许距离分析

外部最小允许距离是《烟花爆竹工程设计安全规范》(GB 50161)中的一个很重要的术语和参数,在烟花爆竹工程设计、验收和安全评价等活动中处于十分重要的地位。解释了标准中外部最小允许距离的定义内涵和外延,强调了最小允许距离的承载主体是危险品生产区厂房、危险品总仓库区仓库等1.1级、1.3级建构筑物,分析了确定最小允许距离的理论依据和前提条件,为标准使用者理解和应用外部最小允许距离术语提供了全面和深入分析。针对目前参数使用中的实际问题,提出了标准修订建议。     

Magnetophoretic separation of Chlorella sp.: Role of cationic polymer binder

Cationic polyelectrolyte promoted effective attachment of iron oxide nanoparticles (IONPs) onto microalgal cells through electrostatic attraction. Poly(diallyldimethylammonium chloride) (PDDA) and chitosan (ChiL), both are cationic polymer, are feasible to act as binding agent to promote rapid magnetophoretic separation of Chlorella sp. through low gradient magnetic separation (LGMS) with field gradient ▿B less than 80 T/m in real time. Cell separation efficiency up to 98% for the case of PDDA and 99% for the case of ChiL can be achieved in 6 min when 3 × 10⁷ cells/mL Chlorella sp. are exposed to 300 mg/L surface functionalized-IONPs (SF-IONPs). Different polyelectrolytes do not give significant effect on cell separation efficiency as long as the particle attachment occurred. However, the PDDA is more preferable as the binder for all type of microalgae medium than the chitosan (ChiL) since it is not pH dependent. SF-IONPs coated with PDDA guarantee the cell separation performance for all pH range of cell medium, with 98.21 ± 0.40% at pH 8.84. On the other hand, the ChiL performance will be affected by the cell medium pH, with only 22.93 ± 31.03% biomass recovery at pH 9.25.     

Charge and separation characteristics of nanofiltration membrane embracing dissociated functional groups

The current work focused on the investigation of charge and separation characteristics of nanofiltration （NF） membrane embracing dissociated functional groups under different electrolyte solutions. The electro-kinetic method was carried out to assess the membrane volume charge density （X） with different salt concentrations ranging from 0.1 to 10 mol. m-3 and different electrolyte species, such as type 1-1, type 2-1 and type 3-1. The Donnan steric pore model-dielectric exclusion （DSPM- DE） model was employed to evaluate the separation characteristics of the NF membrane for wide range of electrolyte concentration （from 25.7 to 598.9mol·m^-3）. The results indicated that the dissociation of the hydro- philic functional groups and the specific adsorption contributed to charge formation on membrane surface. The former played a dominant role in type 1-1 and type 2-1 electrolytes at dilute aqueous solutions （0.1-0.5 mol · m^3）. However, for type 3-1 electrolyte, specific adsorp- tion should contribute to the charge effect to a large extent. Moreover, the correlation between the volume charge density and feed concentration was in accordance with Freundlich isotherm. Furthermore, it was found that the separation characteristic of NF membrane could be evaluated well by DSPM-DE model coupling with electro-kinetic method in a whole concentration range.     

横截面形状对旋风分离器性能影响的数值模拟

采用CFD商业计算软件FLUENT对横截面形状影响旋风分离器性能的情况进行了数值模拟。模拟中,气相采用雷诺应力湍流模型RSM封闭N-S方程,固相采用基于Euler-Lagrange方法的离散相模型DPM。通过对旋风分离器圆形、八边形、七边形、六边形、五边形、四边形横截面形状的比较,模拟并分析了分离器两个主要性能分离效率和压力损失的变化规律,提出了横截面为八边形的分离器的相对优势,可用于传统旋风分离器结构型式的设计和优化。     

Fate of metals contained in waste electrical and electronic equipment in a municipal waste treatment process

In Japan, waste electrical and electronic equipment (WEEE) that is not covered by the recycling laws are treated as municipal solid waste. A part of common metals are recovered during the treatment; however, other metals are rarely recovered and their destinations are not clear. This study investigated the distribution ratios and substance flows of 55 metals contained in WEEE during municipal waste treatment using shredding and separation techniques at a Japanese municipal waste treatment plant. The results revealed that more than half of Cu and most of Al contained in WEEE end up in landfills or dissipate under the current municipal waste treatment system. Among the other metals contained in WEEE, at least 70% of the mass was distributed to the small-grain fraction through the shredding and separation and is to be landfilled. Most kinds of metals were concentrated several fold in the small-grain fraction through the process and therefore the small-grain fraction may be a next target for recovery of metals in terms of both metal content and amount. Separate collection and pre-sorting of small digital products can work as effective way for reducing precious metals and less common metals to be landfilled to some extent; however, much of the total masses of those metals would still end up in landfills and it is also important to consider how to recover and utilize metals contained in other WEEE such as audio/video equipment.     

离子色谱法同时测定水中总氮和总磷

采用碱性过硫酸钾消解—离子色谱法同时测定水中总氮和总磷的含量。该方法避免了国标法中过硫酸钾和氢氧化钠对吸光度的干扰,对总氮和总磷测定的精密度有很大的提高。该方法在实验测定的浓度范围内总氮和总磷的相对标准偏差分别为3.84%和4.24%;总氮和总磷的最低检出限分别为0.007 mg/L和0.009 mg/L,比国标法更低;对实际试样总氮和总磷的加标回收率分别为92.6%～105.3%和94.7%～100.2%。     

教研楼火灾逃生疏散最优通风方式数值试验研究

高校教研楼潜在火灾源与高密度人流共存,火灾逃生疏散是保障灾后人身安全的重要环节。为探索火灾逃生疏散最优逃生条件,应用流体动力学分析软件FLUENT,数值分析防火分隔导致多种通风方式的起火分区温度、烟气场分布规律,研究火场逃生疏散的最优通风方式。结果表明,火灾初期开启防火分隔设施更有利于人员逃生疏散;关闭防火分隔设施条件下,防排烟系统开启略优于关闭;研究背景条件下,开启防火分隔为逃生疏散最优方案;火灾后关闭防火分隔设施可以控制火灾蔓延,降低财产损失,但应在确保人员安全疏散后进行。     

受限空间水幕隔热阻烟性能的试验研

为了研究消防水幕衰减火灾热辐射和阻隔火灾烟气蔓延的隔热阻烟特性,基于搭建的3 m× 3 m × 2.5 m（长×宽×高）小尺寸试验平台,开展大量实体火灾试验,研究水幕作用下空间温度分布特性以及烟气运动规律,并重点分析了喷头压力和喷头类型2种参数对水幕隔热阻烟性能的影响。结果表明:实施水幕分隔对火灾上层高温烟气具有明显的降温作用;实施水幕能够有效阻止火灾烟气的前期扩散;喷头压力越大,水幕的隔热效率越高,当喷头压力增大至0.6 MPa时,水幕的隔热效率可达70%以上;使用ZSTWC撞击式水雾喷头比ZSTM-AT式扇形水幕喷头更有利于形成均匀分布的水幕断面。     

Prenatal diagnosis of infantile hypophosphatasia

Prenatal diagnosis was attempted in a pregnant Japanese woman whose son had died of infantile hypophosphatasia, using chorionic villi sampled at 10 weeks of gestation. Southern blot analysis of restriction fragment length polymorphism was used as a guide, with cDNA for the human liver-type alkaline phosphatase as a probe, and BclI as a restriction enzyme. The fetus was found to be a heterozygote; the pregnancy was allowed to continue; and the baby born was phenotypically normal.