Preparo e caracterização de membranas compostas à base de alginato de cálcio para remoção de eritromicina

Abstract

Membranes composed of nanofiltration (NF) were prepared by spreading a thin layer of calcium alginate (Alg-Ca) on a microporous polyethersulfone (PES) support, followed by cross-linking with calcium chloride. The structural and morphological characteristics of NF composite membranes were determined by FTIR-ATR and SEM. The membrane performance was evaluated in nanofiltration assays and the effect of experimental parameters was investigated, such as: crosslinking concentration, pH effect, porosity and porous support material. The results suggested that the composite membrane Alg-Ca/PESMicro with the best performance was prepared with the alginate concentration of 0.7% (m/v), the calcium chloride concentration of 3.0% (m/v) and cross-linking time of 24 h at 30 °C. The determination of MWCO was performed using the following solutes: glucose, sucrose and PEG (200 ppm) at 5.5 bar and room temperature. The MWCO and the hydraulic permeability of the composite membrane Alg-Ca/PESMicro were equal to 552 Da and 2.6 L/m².h.bar, respectively. The rejection of erythromycin by the Alg-Ca/PESMicro composite membrane was equal to 92%. Thus, it is concluded that the membrane composed of Alg/PESMicro cross-linked with calcium can be successfully used for nanofiltration purposes