ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Fouling of nanofiltration membranes used for separation of fermented glycerol solutions
Justyna Bastrzyk, Marek Gryta, and Krzysztof Karakulski
Institute of Chemical Technology and Environmental Engineering, West Pomeranian University of Technology, ul. Pułaskiego 10, 70-322, Szczecin, Poland
Abstract: In this study, the glycerol solutions were fermented using Lactobacillus casei bacteria. The broths were pre-treated by microfiltration, followed by a further separation with nanofiltration. The latter process was carried out in two stages, using the NF270 and NF90 membranes, respectively. The concentrates thus obtained were enriched with citric acid (first stage) and then with lactic acid and glycerol (second stage). By means of SEM and AFM microscopy, as well as ATR-FTIR analysis, the intensity of membrane-fouling was studied. The colloidal fouling and bio-fouling caused a more than two-fold decrease in the permeate flux during microfiltration of the broth. This pre-treatment stage was effective, and a permeate turbidity of less than 0.2 NTU was obtained. However, the nanofiltration membranes exhibited a 30 % flux decline over the course of the process, mainly due to the organic fouling.
Keywords: glycerol fermentation – Lactobacillus casei – NF270 – NF90 – fouling
Full paper is available at www.springerlink.com.
Chemical Papers 68 (6) 757–765 (2014)