A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1998

Pervaporation can compete with conventional treatment technologies in the removal of the Volatile Organic Compounds (VOCs) like trichloroethylene (TCE) and 1,1,1- trichloroethane (TCEthane) from groundwater to obtain the drinking water standard while simultaneously creating technical problems in the application of conventional groundwater treatment technologies. In this study, TCE was chosen as a pollutant, and TCEthane was considered as a co-contaminant. The concentration of TCE used is limited about 1,000 æg/L by comparing with that in groundwater. The use of a multi-layered composite hollow fiber membrane module with both positive pressure air-stripping and negative pressure air-stripping for separating the VOCs from groundwater was evaluated. The effects of the flow rates of both air and water, the liquid phase composition, the water solution temperature and binary compound on the behavior, mass transport, selectivity and swelling of membrane were studied. The behavior of membrane was also analyzed in relation to vacuum pressure separation process. Among three pervaporation methods tested, the efficiency of TCE removal was obtained in order of the Negative Pressure Air-stripping Process, Positive Pressure Air-stripping Process and the Vacuum Pressure Separation Process. In Negative Pressure Air-stripping Process, 90% of initial TCE concentration (1,000 æg/L) in water can be removed within one hour, and the maximum TCE flux was obtained as 4.716 mgT CE/m2 -hr at an air flow rate of 5 L/min and a water flow rate of 5 L/min.