Excellent dyes removal and remarkable molecular size rejection of novel biopolymer composite membrane

ABSTRACT

The κ-carrageenan mass fraction (F _C) was a key factor to determine membrane character not only on mechanical strength but also on selected molecular permeability. It was defined as the following equation: F _C ≡ (κC[g]/(P[g] + κC[g])) and changed in desired range (0.33–0.83). This study reports the results of mass transfer and ultrafiltration experiments on model dye solutions, indicating Methyl Orange, Indigo Carmine, Bordeaux S, Brilliant Blue, and Rose Bengal, and the reference molecular weight are from 327 to 1017 Da. The fundamental parameters influencing the transport of dye such as experimental temperature, viscosity of the feed solution, initial dye concentrations have been determined. The effective diffusion coefficient of dye molecules in the biopolymer membrane was calculated. Outstanding molecular size recognition was appeared. The molecular weight cut-off values in F _C0.33 membrane were 327 Da, and for F _C0.66 membrane performed the results of 466 Da, respectively. The membrane changed from the wholly compact structure to the porous structure by an increase in the F _C, and then, we proved the changes of membrane formation while F _C value increased scientifically based on a scanning electron microscope (SEM) observation.

Keywords:

• κ-Carrageenan
• Pullulan
• Composite membrane
• Mass transfer
• Diffusion coefficient
• Water permeability

Acknowledgment

This study work was supported by research funding grants provided by the Iijima Memorial Foundation for the Promotion of Food Science and Technology. The authors sincerely thank Dr. Kei Tao of Nihon University, who provided technical assistance on SEM photography.

Notes

7th Aseanian Membrane Society Conference (AMS7), 4–7 July 2012, Busan, Korea