基于乙醇协同作用的柠檬油提取废液中挥发性芳香物的渗透汽化膜分离性能研究

A PDMS/PVDF pervaporation composite membrane was self-made via the coating method and used for separating volatile aromatic compounds from the waste liquid of lemon essential oil processing by pervaporation (PV). The PDMS/PVDF membrane was applied in the pervaporation separation of nerol, α-terpineol, and linalool, which are characteristic aroma components in lemon essential oil waste liquid. The results demonstrated that the PDMS/PVDF membrane had good separation selectivity for the three compounds, but the permeation flux was low. Addition of ethanol significantly affects the separation of aromatics. When the amount of ethanol added is 5% v/v, the permeation fluxes of nerol and linalool increase by 82.93% and 127.76% over those without ethanol. The permeation flux of α-terpineol first increased and then decreased slowly with the increase in ethanol concentration. In addition, the performance of the PDMS/PVDF membrane in separating volatile aroma components in actual lemon oil waste liquid was tested. When the experiment was conducted for 6 h, the types and content of volatile aromatic compounds in the lemon oil waste liquid were significantly reduced. The recovery rates of nerol, α-terpineol, and linalool were 92.50%, 93.37%, and 60.36% respectively. The results showed that the PDMS/PVDF membrane achieved better performance.