Electrokinetic remediation: The use of mercury speciation for feasibility studies applied to a contaminated soil from Almadén

We have chosen the BCR (Bureau Communautaire de Référence) sequential extraction procedure as a speciation analysis to determine the mobility of mercury in the contaminated soil of the Almadén (Spain) mining district. This soil has a high mercury concentration (1000 mg kg⁻¹) in some areas. In previous works, the relationship between the weak-acid soluble fraction and the amount of contaminant recoverable by acid-enhanced electrokinetic remediation (EKR) was shown. In this study, after testing that this relationship is maintained, we test if similar relationships with chelating agents could be established. Recently, several chelating agents were tried and iodide was shown to be quite efficient for the removal of mercury. Thus we have carried out iodide-enhanced EKR experiments at the lab (16 g of soil) and semi-pilot (2 kg) scales. From these experiments it can be concluded that the amount of mercury recoverable by this technique is similar to the one recovered in the batch extraction experiments. Thus, this is another evidence that this kind of experiments can be used for the feasibility studies of the remediation technique. It is also shown that, although the removal efficiency is similar to the one obtained previously for in situ flushing, the time required to achieve this efficiency would be several orders of magnitude shorter for this soil.Nevertheless, the residual Hg present in the weak-acid soluble fraction of the speciation analysis of the soil after the EKR treatment increases with respect to the original contaminated soil, indicating a possible increase of the risks associated to the contaminated site. Therefore, a second EKR treatment is applied to the same soil, this time using acid-enhanced EKR. It is shown that, although almost no Hg was recovered with this technique for the original soil, an important amount can be recovered after the first treatment (iodide-enhanced EKR). Also it is shown that the design and operation of this second technique should be studied carefully due to the rather complex chemistry of the species involved.     

Transparent,fluorescent, and mechanical enhanced elastomeric composites formed with poly (styrene‐butadiene‐styrene) and SiO2‐hybridized CdTe quantum dots

Transparent poly(styrene‐butadiene‐styrene) (SBS)‐quantum dots (QDs) composites (SBS/CdTe QDs) that simultaneously possess strong photoluminescence (PL) and enhanced mechanical properties are presented for the first time based on the facile blending of SiO₂‐hybridized CdTe QDs with SBS. UV–vis spectrum and fluorescence measurement show that SBS/CdTe QDs composites exhibit good optical properties. The results of transmission electron microscopy show good dispersion of CdTe QDs in the SBS matrix. The results of dynamic mechanical thermal analysis indicate that the micro‐phase separated structure of the SBS is exist in the composites, and the presence of CdTe QDs can lead to an decrease of glass transition temperatures of polybutadiene (PB) and polystyrene(PS) domains. In addition, mechanical tests reveal that the addition of CdTe QDs is a useful approach to improve the mechanical properties of SBS. Meanwhile, the fluorescent photographs taken under ultraviolet light prove that SBS/CdTe QDs composites possess strong PL. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

高温高湿盐环境下SBS改性沥青胶浆的高温性能

基于自行设计的室内盐蚀干湿循环试验,采用动态剪切流变仪,对SBS改性沥青胶浆进行温度扫描试验和多重应力重复蠕变恢复(MSCR)试验. 以3.2 kPa应力下的不可恢复蠕变柔量J_nr,3.2为胶浆高温流变性能评价指标,分析试验环境和干湿循环耦合作用对胶浆流变性能的影响. 采用灰色关联理论,探究J_nr,3.2与常规流变参数、干湿循环次数及试验环境之间的关联性. 结果表明,随着盐蚀干湿循环次数的增加,胶浆的复数切变模量、车辙因子及J_nr,3.2均呈增大趋势,相位角和蠕变恢复率呈减小趋势. 在同种试验条件下,硫酸盐环境对胶浆高温性能的影响最大. J_nr,3.2与改进型车辙因子、试验环境的灰色关联度最大,关联度系数均大于0.93. 建议采用日常清扫、定期洒水冲洗的方式来减小路面盐分的积累,提高高温高湿环境中沥青路面的抵抗变形的能力.     

Quantitative analysis on distribution of modifier in microstructure of SBS modified asphalt

A method was developed to make a quantitative analysis of the microstructure of asphalt modified with styrene-butadiene-styrene block(SBS) copolymer. Moreover, both mixed and branched SBS were employed in the preparation of modified asphalt. By sampling specimens from the top, middle, and bottom, a number of microscope slides were made and 400 times micro images were gained. Binarized with the software of MATLAB, the images then went to the process of distribution test, when four typical distributions were employed to investigate the distribution of modifi er spread in asphalt. The distribution characteristic and its parameter were both found. The results show that asphalt phase clearly obeys Poisson distribution, and its parameter, λ, is bond up with the condition SBS performs in. Based on this parameter, indexes can be set up to evaluate the structure of the mixture and its performance as well. Compared with that modifi ed with mixed SBS, the asphalt modifi ed with branched SBS has better performance but worse stability, for it is easier to segregate.     

涪陵工区测井系列优化选择探讨

选择一口井测井系列,主要依据井的区域地质情况,井所钻探的地层是否存在邻井、井所钻探的油藏是否处于生产开发期等因素。测井系列的选择应满足油气勘探、开发的需要,满足地质和工程评价需要等要求。裸眼直井段测井系列选择,除必测项目外,建议增测地层倾角、微电阻率成像、ECS元素俘获测井项目。主要解决地层剥蚀面识别问题。裸眼水平井段测井系列选择,建议增测微电阻率成像、核磁共振、ECS元素俘获测井项目。套管井测井系列选择,建议增测存储式测井项目。创新优选的测井系列和资料采集项目符合中石化南方公司的勘探要求,为涪陵工区页岩气低成本和高效开发提供了必要的技术支持。     

ZS—1型电子选纬装置

ZS-1型电子选纬装置是一种适用于多种无梭织机的配纬器,它主要由数字集成电路和波段开关阵组成。本装置既可与选纬纹板系统等配套,进行任意的纬线选择方式,达到简化机构、降低成本的目的;也可以完全脱离纹板系统,利用一组波段开关,就能实现多达两百万种以上的纬线自动循环方式。     

Impact strength elastomer composites based on polystyrene components separated from waste electrical and electronic equipment

The reuse of plastic components of waste electrical and electronic equipment (WEEE) is an important concern both for environmental issues and to preserve the material resources, with minimum energy consumption. Considering that polystyrene fraction was reported as approximate 80% of the total amount of WEEE plastic, this article aims to evaluate the recycling of this fraction, without separation by components, by melt compounding with styrene-butadiene block-copolymer (SBS) and hydrogenated and maleinized SBS, the blend of the two elastomers acting both as an impact modifier and compatibilizer. The composites are characterized by mechanical analysis, impact tests, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction. The recycling conditions of the polystyrene fraction as composites without eliminating the WEEE additives for improved UV and flame resistance, with physical mechanical properties comparable to those of high-impact polystyrene resulted from the study. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48329.     

SBS热塑性弹体改性沥青的研究

采用SBS改性100号道路沥青的实验结果表明,在沥青加入10—12phr的SBS,能大幅度地提高沥青的软化点及耐低温性能,同时降低沥青在高温季节蠕变形成涌包,冬季易脆裂的问题。     

全动型变焦距物镜光焦度分配及倍率选段的优化规范

本文在讨论了最速变焦路线和权重光焦度的基础上,提出了全动型变焦距物镜光焦度分配及倍率选段的优化规范,并在IBM-PC/XT微型机上编制了相应的优化程序,给出了数值实例。结果表明,该优化规范和程序是可行和有效的。     

常用水箱液位计的选择

介绍了水箱计量的目的、方法,以及水箱常用液位计的基本原理、特点和应用场合。根据不同液位计的性能特点提出了液位计的选型原则。