Robbins C A, Breysse P N
Johns Hopkins University School of Hygiene and Public Health, Department of Environmental Health Sciences, Baltimore, MD 21205, USA.
Am Ind Hyg Assoc J. 1996 Aug;57(8):717-23. doi: 10.1080/15428119691014576.
This research evaluated the effect of the polarity of a second vapor on the adsorption of a polar and a nonpolar vapor using the Wheeler model. To examine the effect of polarity, it was also necessary to observe the effect of component boiling point. The 1% breakthrough time (1% tb), kinetic adsorption capacity (W(e)), and rate constant (kv) of the Wheeler model were determined for vapor challenges on carbon beds for both p-xylene and pyrrole (referred to as test vapors) individually, and in equimolar binary mixtures with the polar and nonpolar vapors toluene, p-fluorotoluene, o-dichlorobenzene, and p-dichlorobenzene (referred to as probe vapors). Probe vapor polarity (0 to 2.5 Debye) did not systematically alter the 1% tb, W(e), or kv of the test vapors. The 1% tb and W(e) for test vapors in binary mixtures can be estimated reasonably well, using the Wheeler model, from single-vapor data (1% tb +/- 30%, W(e) +/- 20%). The test vapor 1% tb depended mainly on total vapor concentration in both single and binary systems. W(e) was proportional to test vapor fractional molar concentration (mole fraction) in mixtures. The kv for p-xylene was significantly different (p < or = 0.001) when compared according to probe boiling point; however, these differences were apparently of limited importance in estimating 1% tb for the range of boiling points tested (111 to 180 degrees C). Although the polarity and boiling point of chemicals in the range tested are not practically important in predicting 1% tb with the Wheeler model, an effect due to probe boiling point is suggested, and tests with chemicals of more widely ranging boiling point are warranted. Since the 1% tb, and thus, respirator service life, depends mainly on total vapor concentration, these data underscore the importance of taking into account the presence of other vapors when estimating respirator service life for a vapor in a mixture.
本研究使用惠勒模型评估了第二种蒸汽的极性对极性蒸汽和非极性蒸汽吸附的影响。为了研究极性的影响，还需要观察组分沸点的影响。分别针对对二甲苯和吡咯（称为测试蒸汽）以及与极性和非极性蒸汽甲苯、对氟甲苯、邻二氯苯和对二氯苯（称为探针蒸汽）的等摩尔二元混合物，测定了碳床蒸汽挑战下惠勒模型的1%穿透时间（1%tb）、动力学吸附容量（W(e)）和速率常数（kv）。探针蒸汽极性（0至2.5德拜）并未系统地改变测试蒸汽的1%tb、W(e)或kv。使用惠勒模型，根据单蒸汽数据（1%tb±30%，W(e)±20%）可以较好地估计二元混合物中测试蒸汽的1%tb和W(e)。测试蒸汽的1%tb在单系统和二元系统中主要取决于总蒸汽浓度。W(e)与混合物中测试蒸汽的摩尔分数成正比。根据探针沸点比较时，对二甲苯的kv有显著差异（p≤0.001）；然而，在测试的沸点范围（111至180℃）内，这些差异在估计1%tb时显然重要性有限。尽管在所测试范围内化学品的极性和沸点在使用惠勒模型预测1%tb时实际意义不大，但表明存在探针沸点的影响，因此有必要对沸点范围更广的化学品进行测试。由于1%tb进而呼吸器使用寿命主要取决于总蒸汽浓度，这些数据强调了在估计混合物中一种蒸汽的呼吸器使用寿命时考虑其他蒸汽存在的重要性。
