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

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.