Dong Y, Bai Z, Liu R, Wang X, Yan H, Zhu T
State Environmental Protection, Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Sciences and Engineering, Nankai University, 94 # Weijin Rd., Tianjin 300071, China.
Environ Technol. 2006 Jul;27(7):705-14. doi: 10.1080/09593332708618688.
Addition of urea-based antifreeze admixtures during cement mixing can make it possible to concrete cement in construction of buildings in cold weather. This, however has led to increasing indoor air pollution due to continuous transformation and emission from urea to gaseous ammonia in indoor concrete walls. In order to control ammonia from indoor concrete walls, aqueous dispersion of nano-titanium dioxide (TiO2) was prepared and mixed with silicone additive to establish a treating bath. Cotton fabrics were finished with this treating bath by using pad-dry-cure process and then characterized by X-Ray Diffractometer, Infrared Fourier Transform Spectrometer and Scanning Electron Microscope. The gaseous ammonia was derived from an environmental condition simulated chamber. The heterogeneous decomposition of gaseous ammonia by UV/TiO2 process in an annular photoreactor fixed with the TiO2-coated cotton fabric was studied under various dosages of aqueous nano-TiO2 dispersion, initial ammonia concentration, relative humidity and gas flow rate. A design equation of surface catalytic kinetics was developed for describing the decomposition of ammonia in air streams by UV/TiO2 process at given operating conditions. Experimental results indicated that increasing dosage of aqueous nano-TiO2 dispersion improved the ammonia decomposition of cotton fabric, which was prepared. At a constant temperature of 25 degrees C, ammonia in the air stream was effective removed by decreasing initial ammonia concentration and gas flow rate. For moisture in the range of 15-65%, when the relatively humidity level was increased to 45%, the decomposition of ammonia was remarkably enhanced, and the decomposition of ammonia could be inhibited by excessive moisture.
在水泥搅拌过程中添加基于尿素的防冻外加剂，能够使在寒冷天气下建造建筑物时的水泥得以浇筑。然而，这却导致室内空气污染加剧，原因是室内混凝土墙中的尿素持续转化并释放出气态氨。为了控制室内混凝土墙产生的氨气，制备了纳米二氧化钛（TiO₂）水分散体，并与有机硅添加剂混合以建立处理浴。采用浸轧-烘干-焙烘工艺用此处理浴对棉织物进行整理，然后用X射线衍射仪、红外傅里叶变换光谱仪和扫描电子显微镜对其进行表征。气态氨来自环境模拟舱。在不同剂量的纳米TiO₂水分散体、初始氨浓度、相对湿度和气体流速条件下，研究了固定有TiO₂涂层棉织物的环形光反应器中UV/TiO₂工艺对气态氨的多相分解。建立了表面催化动力学设计方程，用于描述在给定操作条件下UV/TiO₂工艺对气流中氨的分解。实验结果表明，增加纳米TiO₂水分散体的剂量可提高所制备棉织物的氨分解率。在25℃恒温下，通过降低初始氨浓度和气体流速可有效去除气流中的氨。对于15%至65%范围内的湿度，当相对湿度水平提高到45%时，氨的分解显著增强，而过多的水分会抑制氨的分解。
Zotero 插件