High-Selectivity Pervaporation Membranes for 1-Butanol Removal from Wastewater

Abstract

Possibility of using polydecylmethylsiloxane in the pervaporation removal of organic compounds from aqueous media was examined. It was shown for the example of the system with 1 wt % n-butanol in water that this material is characterized by a large separation factor (69), which twice exceeds the separation factor of the commercial membrane polymer polydimethylsiloxane. A composite membrane was produced on the basis of polydecylmethylsiloxane. The selective layer was deposited from a solution of the polymer by the touching method onto an MFFK-1 domestic microfiltration substrate. Pervaporation experiments with the new composite membranes based on polydecylmethylsiloxane were used to determine the optimal separation mode of the water–butanol mixture: delivery rate of the mixture to be separated, 1.2 cm s–₁; and separation temperature 40°C. It was shown that, at a selective layer thickness of about 4.5 μm, it is possible to reach a permeability of the PDecMS/ MFFK-1 membrane that is comparable with the permeability for 1-butanol of commercial composite membranes (5.2 mol m–₂ h kPa_–1). However, the butanol/water selectivity for the PDecMS/MFFK-1 membrane is 3–7 times that of the commercial membranes.