用密闭小室测定建材VOC散发特性

建筑材料散发的有机挥发物(VOC)能影响室内空气品质,为研究建材VOC的散发情况,提出了一种测量建材VOC散发特性(初始VOC平均浓度、分离系数)和对流传质系数的方法.选取了几种常见建材(复合地板、大芯板、地板砖和地毯)的甲醛散发作为测试对象,在密闭不锈钢小室内测量建材的甲醛散发曲线,用穿孔萃取仪测量建材内甲醛的平均浓度,通过拟合测量结果可以得出建材的散发参数.测试方法和测量结果为建材的筛选和VOC散发性能评价提供了参考依据.     

关于食品包装卫生要求的检测

随着包装工业的迅速发展,人们对于包装材料提出了越来越明确的要求,尤其是在食品包装领域.食品包装材料是与人们的日常生活紧密联系在一起,因而食品生产厂家对于食品包装材料也提出了各种要求.油墨虽然不是直接的包装材料,但它是包装材料中的重要组成部分之一,所以也对它提出卫生要求.     

活性碳纳米纤维对VOC的吸附性能

通过对比不同直径的活性碳纳米纤维及活性碳纤维对苯、甲苯和乙醇蒸汽的吸附等温线,研究不同直径的活性碳纳米纤维及活性碳纤维吸附挥发性有机物(VOC)气体性能的差异。经扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)等测试分析,结果表明:活性碳纤维直径在10μm数量级,随直径减小,纤维晶体性变差,结构无序性增大;微孔达0.4～0.8 nm时VOC气体分子更易进入与吸附位结合;活性碳纳米纤维及活性碳纤维氮吸附-脱附曲线均为Ⅰ型。故分压比低于0.01时活性碳纳米纤维对苯、甲苯和乙醇的吸附量要高于活性碳纤维的吸附量。     

汽车挥发性有机物的采样分析及其防治对策

车内环境质量的好坏对人的身体健康有直接影响。近年来,随着国内汽车保有量的增加,有车族们在车内度过的时间也越来越多,汽车内空气污染给人体健康带来的危害也逐渐被社会所关注。本文旨在研究汽车内空气污染物VOC(挥发性有机化合物)的来源、采样、分析及对策。     

绿色过程工程中的绿色涂料进展

绿色过程工程是当今国际过程工程科学发展的前沿。介绍了世界涂料发展的趋势,指出绿色涂料的研究方向应该向高固体份涂料、溶液无溶剂涂料、粉末涂料及辐射固化涂料和水性涂料发展。     

Numerical simulation for volatile organic compound removal in rotating drum biofilter

Rotating drum biofilters (RDBs) could effectively remove volatile organic compounds (VOCs) from waste gas streams. A mathematical model was developed on the basis of mass transport and mass balance equations in an RDB,the two-film theory,and the Monod kinetics. This model took account of mass transfer and biodegradation of VOC in the gas-water-biofilm three-phase system in the biofilter,and could simulate variations of VOC removal efficiency with a changing specific surface area and porosity of the media due to the increasing of biofilm thickness in the biofilter. Toluene was used as a model VOC. This model was further simplified by introducing a coefficient of the gas velocity and ne-glecting the water phase due to the complexity of operating conditions. The equations for the biofilm phase,gas phase,and biofilm accumulation in this model were solved using collocation method,ana-lytic method,and the Runge-Kutta method separately. A computer program was written down as MATLAB to solve this model. Results of numerical solutions showed that toluene removal efficiency in the RDB increased and reached the maximum values of 97% on day 4 after the startup,and then de-creased and remained at 90% after 5 more days of operation. Toluene concentration was high at the outermost layer where more than 70% toluene was removed,and was low at the innermost layer where less than 10% toluene was removed. The dynamic removal efficiencies from this model correlated reasonably well with experimental results for toluene removal in a multi-layered RDB.     

基于小环境舱测试的实际车内VOC浓度预测

乘用车内饰释放的挥发性有机物（VOC）严重影响车内空气质量. 车内材料中VOC的释放特性主要由3个释放关键参数表征:初始浓度C₀,扩散系数D_m和分配系数K. 文中应用直流舱C-history法测定了几种典型乘用车内饰中6种VOC的释放关键参数,并研究了温度的影响. 此外,建立了预测实际车内多源材料同时释放VOC时浓度变化的多源释放模型,并模拟实际车内环境建立了3 m3试验系统进行验证实验. 实验结果与模型预测结果吻合较好,说明通过小环境舱测定的释放关键参数能够用于预测实际车内多种内饰共存时污染物的释放情况.      

A mass transfer model for predicting emission of the volatile organic compounds in wet building materials

A new mass transfer model is developped to predict the volatile organic compounds （VOCs） from fresh wet building materials. The dry section of wet materials during the process of VOC emission from wet building materials is considered in this new model, differing from the mass transfer-based models in other literatures. The mechanism of effect of saturated vapor pressure on the surface of wet building materials in the process of VOC emission is discussed. The concentration of total volatile organic compounds （TVOC） in the building materials gradually decreases as the emission of VOCs begins, and the vapor pressure of VOCs on the surface of wet building materials decreases in the case of newly wet building materials. To ensure the partial pressure of VOCs on the surface of wet building materials to be saturated vapor pressure, the interface of gas-wet layer is lowered, and a dry layer of no-volatile gases in the material is formed. Compared with the results obtained by VB model, CFD model and the experiment data, the results obtained by the present model agree well with the results obtained by CFD model and the experiment data. The present model is more accurate in predicting emission of VOC from wet building materials than VB model.     

钴基复合氧化物氧化降解甲苯的结构与催化性能

采用溶胶-凝胶法制备了钴基复合氧化物A-Co（A=Cu,Mn,Ce）,测定和评价了A-Co复合催化剂氧化降解甲苯的催化性能.结果表明,二元钴基复合氧化物氧化降解甲苯的催化活性均优于纯钴氧化物催化剂,其中,Ce-Co氧化物的t10和t90(分别为达到10%和90%的甲苯转化的温度)分别为221,238 ℃,催化活性最高.在240 ℃连续使用50 h,Ce-Co氧化降解甲苯降解转化率仍为99%以上,具有较好的催化稳定性.应用X射线衍射、氮气吸脱附、扫描电子显微镜、氢气程序升温还原和X射线光电子能谱等表征技术,研究了钴基催化剂的结构与催化性能的关系,在Ce-Co催化剂上形成的Ce⁴⁺/Ce³⁺和Co³⁺/Co²⁺氧化还原对促进了催化剂上氧的迁移,提高了表面氧的可还原性,在甲苯氧化降解过程中产生协同作用.     

浅谈工业涂料VOC的排放与PM2.5的关系

随着工业化建设,环保意识已经逐渐引起人们的重视,2013年初,北京上海等一线城市均出现雾霾现象,并引PM2.5的概念。该文通过调研及统计数据指出工业涂料VOC排放是PM2.5的重要影响因素,甚至会产生更大的危害,并进一步提出解决办法和建议,呼吁节能减排。