Keller A A, Bierwagen B G
Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, California 93106, USA.
Environ Sci Technol. 2001 May 1;35(9):1875-9. doi: 10.1021/es001490y.
Soluble contaminants with low Henry's constant, such as methyl tert-butyl ether (MTBE), require innovative solutions for water treatment. Given the increased frequency at which MTBE is detected at contaminated sites, the development of new technologies is of considerable relevance. Hydrophobic hollow fiber membranes (HFM), used in industrial and medical applications, have interesting physicochemical properties that make them particularly suitable to deal with these contaminants. The hydrophobicity of the fiber maintains adequate separation between aqueous and gaseous phases, permitting an efficient separation of volatile and semivolatile compounds from water to gas. The hollow nature of the fiber and its high porosity permit high rates of mass transfer across the membrane. The mass transfer process can be accelerated using pervaporation and by increasing the solution's temperature to increase the Henry's constant and the overall mass transfer coefficient. In these studies, we evaluate the removal efficiency of MTBE from water using a commercial HFM module and develop the corresponding dimensionless mass transfer correlations necessary for the design of industrial-scale systems. We found that the Lévêque correlation for the tube-side mass transfer coefficient is in general applicable for MTBE pervaporation through a hydrophobic HFM. MTBE removal is a strong function of membrane length, water flowrate, and solution temperature but is almost independent of gas-phase parameters.
具有低亨利常数的可溶性污染物，如甲基叔丁基醚（MTBE），需要创新的水处理解决方案。鉴于在受污染场地检测到MTBE的频率增加，开发新技术具有相当重要的意义。用于工业和医疗应用的疏水性中空纤维膜（HFM）具有有趣的物理化学性质，使其特别适合处理这些污染物。纤维的疏水性在水相和气相间保持足够的分离，从而能够有效地将挥发性和半挥发性化合物从水中分离到气体中。纤维的中空性质及其高孔隙率允许跨膜的高传质速率。可以使用渗透蒸发并通过提高溶液温度来增加亨利常数和总传质系数来加速传质过程。在这些研究中，我们使用商用HFM模块评估了从水中去除MTBE的效率，并开发了工业规模系统设计所需的相应无量纲传质关联式。我们发现，管侧传质系数的勒维克关联式通常适用于MTBE通过疏水性HFM的渗透蒸发。MTBE的去除强烈依赖于膜长度、水流速和溶液温度，但几乎与气相参数无关。
