三氯乙烯生产中再沸器的泄漏原因及处理措施

分析三氯乙烯生产中再沸器的泄漏主要由酸腐蚀和应力腐蚀引起,提出处理措施,保证三氯乙烯装置的稳定运行。     

水中三氯乙烯的去除研究进展

叙述了三氯乙烯的毒性和世界健康组织对其在饮用水中的限定浓度以及各种去除方法：活性炭吸附、空气吹脱、膜分离技术、高级氧化和生物降解法等，特别是用溶胶凝胶法合成的TiO2小球作为催化媒体的光催化法。需要呼吁有关技术人员尽快开发新型、有效和无毒的脱脂剂和氯化溶剂的替代产品，从源头上控制三氯乙烯的污染。     

Electrolytic oxidation of trichloroethylene using a ceramic anode

Trichloroethylene (TCE) was transformed to CO₂, CO, Cl^– and ClO₃^– at the anode of a two-chambered electrolytic cell. The working electrode was constructed from Ebonex^®, an electrically conductive ceramic (Ti₄O₇). Under our experimental conditions (anode potential E_a = 2.5 to 4.3 V vs SSCE), the disappearance of TCE was first order in TCE concentration. The transformation rate was independent of pH in the range 1.6 < pH < 11. TCE oxidation occurred only on the anodic surface and was limited by mass transport at high potentials (E_a > 4.0V). The maximum (transport-limited), surface-area-normalized rate constant was about 0.002 43cms^–1. Carbon-containing products included CO₂ primarily with traces of CO. At neutral and alkaline pHs, the only chlorine-containing products were Cl^– and ClO₃^–. Hydroxyl radicals were detected in the anodic compartment using a spin trap (4-POBN). A kinetic model was successfully correlated with experimental results.     

Reaction Kinetics of Ozonation of Trichloroethylene and Benzene in Gas and Liquid Phase

The kinetics of ozonation reactions oftrichloroethylene (TCE) and benzene in gas and liquid phases at101.3 kPa and 298 K was investigated in this paper. The ozonation ofTCE is first order with respect to the ozone concentration and one andhalf order to TCE in the gas phase with the average rate constant 57.30(mol*L-1)-1.5 *s-1, and the TCE ozonation inaqueous medium is first order with respect to both ozone andtrichloroethylene with the average rate constant 6.30(mol*L-1)-1 *s-1. The ozonation of benzene inthe gas phase is first order in ozone but independent of the benzeneconcentration with the average reaction rate constant 0.0011 s-1.The overall kinetics of reaction between ozone and benzene in aqueoussolution is found to be first order with one-half order in both ozoneand bezene, with the average reaction rate constant 2.67 s-1. Itis found that the ozonation rate of pallutants is much quicker than that ofself-decomposition of ozone in both gas and aqueous phase.     

Source apportionment of trichloroethylene in groundwater of the industrial complex in Wonju,Korea: a 15‐year dispute and perspective

The groundwater of an industrial complex has been contaminated with trichloroethylene (TCE) since 1995. High levels of TCE exceeding the Korean groundwater standard can still be found. However, ongoing controversial debate on the contamination source has hindered the remedial works. Wonju city suggested a single source, while the Gangwon Province considered multiple sources. The TCE plume appeared as two separate plumes rather than a single plume. Carbon tetrachloride (CT), a formerly used solvent, formed a plume but its extent was restricted to the left half of the overall TCE plume. The soil contamination survey revealed the existence of at least two contamination source areas. All the evidences pointed to the asphalt test laboratory as being one of the major sources, but the possibility of other sources cannot be excluded. The maximum extent of the TCE contamination caused by the asphalt laboratory may have been restricted to the left half of the overall TCE plume.     

利用Voronoi图改进离散数据重构曲面算法

本文利用Delaunay三角剖分和 Voronoi图的性质,实现了一种对散乱点重构闭合曲面的方法。该方法在搜索策略上进行了改进：首先对输入点进行三角剖分,产生相互独立的四面体,构建一个凸包;然后利用Delaunay三角剖分产生Voronoi图;最后根据Voronoi图的性质,选择包含在形体内部的四面体,提取出边界三角形,完成散乱点边界重构。计算复杂度和Delaunay四面体数量成正比,在自动形状重构时形状边界提取过程的计算复杂度为O(n),算法适用于各种涉及图形重构的工程应用。     

The role of hydrophilic linkers

In microemulsion formulations, linker molecules are additives that can enhance the surfactant-oil interaction (lipophilic linkers) or the surfactant-water interaction (hydrophilic linkers). In this paper, the role of the hydrophilic linker is elucidated through solubilization studies, interfacial tension studies, and by studying the partitioning of the hydrophilic linker into an optimum middle phase. This research used alkyl naphthalene sulfonates as the hydrophilic linkers, sodium dihexyl sulfosuccinate as the surfactant, and trichloroethylene as the oil phase. The hydrophilic linkers were found to have interfacial properties between a hydrotrope and a cosurfactant. More specifically, the data show that a hydrophilic linker is an amphiphile that coadsorbs with the surfactant at the oil/water interface but that has negligible interaction with the oil phase. The role of the hydrophilic linker can thus be interpreted as opening “holes” in the interface. Based on the characteristics of alkyl naphthalene linkers, carboxylic molecules were evaluated as hydrophilic linkers. For trichloroethylene microemulsions, sodium octanoate was found to be an alternative hydrophilic linker to sodium mono- and dimethyl naphthalene sulfonates.     

PAC Addition for MBR Start up in Micro-polluted Water Treatment

In order to improve membrane reactor ( MBR ) performance for micro?polluted surface water treatment in start?up phase, removals of nitrogen and organic matters especially synthetic organic matters by M...     

Polymer material-supported titania nanofibers with different polyvinylpyrrolidone to TiO2 ratios for degradation of vaporous trichloroethylene

Polymer-supported TiO₂ nanofibers with different polyvinylpyrrolidone (PVP)-to-TiO₂ (PT) ratios were synthesized and their photocatalytic efficiencies were examined for the decomposition of trichloroethylene (TCE). The spectral results of the TiO₂ nanofibers confirmed the presence of TiO₂ crystal phases in the nanofibers. The TiO₂ nanofiber with the highest PT ratio of 1:1.3 showed the highest TCE decomposition (94%), followed by TiO₂ nanofibers with PT ratios of 1:0.7 (91%), 1:0.35 (88%), and 1:0.1 (84%). The conditions of low input concentration and humidity were suggested for the optimal decomposition of TCE. Consequently, the TiO₂ nanofiber webs could be used effectively to decompose TCE.     

曝气吹脱法去除水中三氯乙烯等有机污染物

在实验室洗气瓶试验条件下,研究了不同曝气流量以及曝气时间即气水比大小对三氯乙烯和四氯乙烯吹脱去除率的影响。结果表明三氯乙烯和四氯乙烯在曝气量为0．4～1．4L／min的试验条件下,气水比分别在2．24～4．71（气）／L（水）和1．10～2．43（气）／L（水）范围内能将初始浓度为国家标准5倍的三氯乙烯和四氯乙烯去除到国家标准限值以内,所需时间均在30min以内。试验结果表明曝气吹脱法能在较短短时间内有效去除三氯乙烯和四氯乙烯,可以作为有效去除挥发性污染物的应急处理技术。