(353e) Removal of Volatile Organic Compounds from Water by Use of Microcapsules Containing PDMS

Volatile organic compounds(VOCs) in the wastewater have negative effects on environment and human health and development of efficient method to remove VOCs from water is an important task. In this study, poly(dimethylsiloxane) (PDMS) was found as a green extractant with large extraction capacity. However, because of its high viscosity, it is not suitable to be applied in liquid-liquid extraction directly. Therefore, PDMS was encapsulated in polyacrylonitrile microspheres as separation agent. The microspheres were prepared by solvent extraction method through a microfluidic device. The PDMS microcapsules had narrow size distribution and their mean diameter was about 500 µm. Microcapsules were employed to deal with wastewater containing low concentration of toluene, ethyl acetate and benzene respectively and the mass transfer performance of microcapsules was determined. Extraction equilibrium could be reached within 30min in batch experiment and microcapsules were reused for 4 times and no decline in the quantity of VOCs extracted was observed. The PDMS microcapsules can remove VOCs from water efficiently with no adverse coupling effects. A simple model was applied to batch experiments and the particle diffusion is probable the rate-controlling step of the process of extraction.