甲苯气体的动态吸附净化及吸附剂再生实验研究

研究了活性炭纤维(ACF)对甲苯气体的动态吸附净化过程及热空气解吸脱附再生过程.采用3种经验方程对ACF的吸附等温线进行拟合,其中Langmuir方程拟合效果最好,拟合相关系数R2 =0.9960,说明在给定的浓度范围内,ACF对甲苯的吸附是以单分子层吸附为主.穿透曲线实验表明,ACF对甲苯吸附效果较好,Yoon-Ne...     

Incident investigation of mono-nitro toluene still explosion

At one of the nitro-toluene facilities, an o-nitro toluene still was in standby mode. During the standby mode feed to the still had been stopped, the column was not de-inventoried, steam flow to the reboiler was not shut off and the condenser was on total reflux. After 22 days of standby mode, steam was shut off for 5 days for annual plant maintenance. Eight days after the re-start of steam, the still exploded, hurling debris as far as one mile. The internal packing was expelled from the column and landed on the ground burning. The incident was investigated to establish the contributing factors leading to explosion. Accelerating Rate Calorimetery was extensively used to determine the onset temperature for exothermic activity in the presence/absence of a number of materials to establish the underlying cause of the accident. It was found that foulant collected in the column over a period of years accelerated the ’runaway reaction’.     

负载型钌铈催化剂的甲苯催化氧化性能

以ZSM-5分子筛为载体,采用浸渍法制备了RuCe/ZSM-5催化剂,研究了催化剂在不同Ru负载量、空速、反应温度、甲苯浓度下对甲苯的催化氧化性能,并探讨了催化剂的CO₂选择性及稳定性。结果表明：Ru的负载可提升CeO₂(20)/ZSM-5催化剂催化甲苯使其降解成高浓度CO₂的能力;Ru(1.0)/CZ催化剂表现出优异的低温催化性能、CO₂选择性及稳定性,在210 ℃条件时即可转化90%的甲苯,且CO₂选择性达到90%以上。本研究制备的催化剂在较大空速及甲苯浓度范围内对甲苯具有优越的低温催化性能,未来可应用于VOC的工业化处理应用中。     

CdS-TiO2/MWCNTs结构表征及其光催化性能

采用溶胶-凝胶法,制备了多壁碳纳米管（MWCNTs）负载的双组分复合半导体光催化剂CdS-TiO2/MWCNTs。通过透射电镜（TEM）、比表面分析（BET）、X射线衍射（XRD）和紫外-可见吸收光谱（UV-vis）等分析方法对光催化剂进行了结构表征,并考察了CdS-TiO2/MWCNTs对甲苯降解的光催化性能。结果表明：纳米活性粒子CdS-TiO2均匀负载于MWCNTs上,比表面积、光吸收阈值和强度增大,活性粒子间以及活性粒子与载体之间具有协同作用,有利于光催化性能的提高,CdS-TiO2/MWCNTs在主波长为254 nm紫外光照射下对甲苯的降解效果较好,去除率可达55.3%。     

地下水浅埋区某加油站特征污染物空间分布

加油站渗漏污染地下水已经是一个世界性的问题。由于浅埋区加油站储罐与地下水密切接触,更加剧储罐的腐蚀。为揭示加油站渗漏的典型污染物石油烃（TPH）、苯系物（BTEX）、萘和甲基叔丁基醚（MTBE）在该水文地质条件下的迁移变化,在浅埋区某加油站开展了平、枯、丰水期的地下水监测工作。在水平分布上,TPH、BTEX、萘基本相似,均在加油岛附近形成高浓度区,而MTBE则更易随地下水流动而迁移,呈现出不同的污染晕。在垂直分布上,地下水的水位变动是污染物浓度分布的主要影响因素。     

回收涂布生产废气中甲苯的新型装置

文章介绍了从涂布生产废气中回收甲苯的新型自动化回收工艺和装置。与传统的颗粒活性炭装置相比，该装置由于采用了性能优越的吸附材料和先进的工艺设计，使甲苯的回收率达95％以上，而且回收的甲苯品质好，可以直接作为原料使用，实现了清洁生产和废气资源化，收到了很好的环境效益和经济效益。     

微波辐照载甲苯活性炭再生研究

研究在微波辐照条件下,活性炭量、微波功率、载气量、加热时间等因素对载甲苯活性炭脱附的影响,在正交实验中,各个影响因素的重要性排序为：氮气流量、活性炭量、辐照时间、微波功率,最佳的操作工况为：活性炭量9 g、载气流量300 mL/min、辐照时间120 s、微波功率500W,活性炭的脱附率在99.74%.     

Human health risks of petroleum-contaminated groundwater

BACKGROUND, AIM AND SCOPE: The volatile organic compounds Benzene, Toluene, Ethylbenzene and Xylene (BTEX) are commonly found in petroleum derivatives and, at relatively high levels, can be associated with human health risks. Due to industrial activities, accidental petroleum spills are the main route of soil and groundwater contamination. The aim of the present study was to evaluate the indoor health risks due to tap water consumption contaminated by BTEX. MATERIALS AND METHODS: BTEX indoor exposure can occur through three principal pathways: inhalation, ingestion and dermal absorption. A multiphase and multicomponent model was used to simulate BTEX transport in groundwater. For evaluation of human risks due to the use of contaminated tap water, a mathematical model was elaborated. RESULTS: BTEX concentrations in a drinking well were obtained as a function over time. These concentrations were used to obtain the exposure due to the use of water from the contaminated drinking well. In addition to showing the highest concentration in water, benzene was the compound that remained for a longer period before being completely degraded. For all the evaluated BTEX, oral ingestion was also the main pathway of exposure for adults, whereas the contribution of inhalation and oral exposition in children were seen to be of the same magnitude. The sensitivity analysis of BTEX total dose for adults showed that direct ingestion was the most significant factor, followed by shower time, volume of the shower room, inhalation rate, and shower flow rate. For children, the most significant variable was also direct ingestion, followed by shower time, volume of the shower room, and body weight. DISCUSSION: In the current design situation, there would not be any health risks by the use of BTEX-contaminated water to the general population living in the neighborhood of the petroleum spill. Therefore, no remediation measures in the area of the spill would be necessary. CONCLUSIONS: The present results indicate that the design of a good scenario can perform an accuracy risk assessment. This model can serve as a useful tool for predicting indoor exposure to substances for which no direct data are available, reducing monitoring efforts and observing how different processes affect outcomes. RECOMMENDATIONS AND PERSPECTIVES: These preliminary data allow the establishment of a basis for further investigations focusing on efficiently recovering petroleum from contaminated sites.     

Atmospheric Volatile Organic Compound Monitoring. Ozone Induced Artefact Formation

Assessment of population exposure to VOC in ambient atmospheres is receiving heightened interest as the adverse health effects of chronic exposure to certain of these compounds are identified. Active (pumped) and passive samplers are the most commonly used devices for this type of monitoring. It has been shown, however, that these devices, along with all other preconcentration techniques, are susceptible to ozone interference. It is demonstrated that this interference occurs even at low ozone concentrations and that it may result in the under-estimation of population exposure. A convenient and effective ozone scrubbing method is identified and successfully applied and validated for both active and passive samplers for a range of VOC.     

异氰酸酯生产过程中危险有害因素及安全防护措施

介绍二苯基甲烷二异氰酸脂(MDI)、甲苯二异氰酸醋(TDI)这两种最常见的主要异氰酸醋的生产工艺技术概况;分析其生产过程中异氰酸脂、光气、氯气泄漏事故和存在的危险有害因素;辨识出异氰酸醋生产过程中的主要危险有害因素为毒性危害、火灾、爆炸危险等;提出相应的国际5层次安全防护措施,即选择合适的工艺路线、采用严格的设计条件、增加快速高效的在线监测、切实可行的监控和减缓措施、组织机构和安全管理措施,提出异氰酸醋生产和生产装置设计应严格遵守<光气及光气化产品生产安全规程>的要求.