Diclofenac Transport through Stagnant Sandwich and Supported Liquid Membrane Systems

The removal of a drug, diclofenac (DCF), from aqueous media by using a supported liquid membrane (SLM) and a stagnant sandwich LM (SSwLM) has been investigated. The two systems were compared in terms of flux and stability. Optimal chemical conditions were determined by means of liquid-liquid extraction tests. In the transport tests, the obtained results indicated a higher initial flux J0 (2.4 vs 1.3 mmol/h.m^2) and a faster transport (counter transport reached at 1.75 vs 26.3 h) for the SLM system than for the SSwLM system. The diclofenac transport in the SLM from the feed to the strip was quite complete after 3 h, whereas in the SSwLM, only 39% of the initial drug was recovered in the strip phase after 30 h. Higher system stability was obtained using the SSwLM system (>120 vs 47.5 h). The overall results obtained in this work showed that liquid membrane systems can effectively be used to remove pharmaceuticals present at low concentration in wastewaters.