Cross-Flow Microfiltration of Glycerol Fermentation Broths with Citrobacter freundii

Abstract

This paper reports the study of the cross-flow microfiltration (MF) of glycerol fermentation broths with Citrobacter freundii bacteria. A single channel tubular ceramic membrane with a nominal pore size of 0.14 µm was used. It has been demonstrated that the MF ceramic membrane has been successfully applied to bacteria cell removal and to effectively eliminate colloidal particles from glycerol fermentation broths. However, due to fouling, the significant reduction of the MF performance has been demonstrated. In order to investigate the impact of transmembrane pressure (TMP) and feed flow rate (Q) on MF performance, 24 experiments have been performed. The highest steady state permeate flux (138.97 dm3/m2h) was achieved for 0.12 MPa and 1000 dm3/h. Fouling analysis has been studied based on the resistance-in series model. It has been found that the percentage of irreversible fouling resistance during the MF increases with increasing TMP and Q. The permeate flux regeneration has been achieved by membrane cleaning with 3 wt % NaOH and 3 wt % H3PO4 at 45 °C. The results of this study are expected to be useful in industrially employing the MF process as the first step of glycerol fermentation broth purification.

Recent Advances on Purification of Lactic Acid

“…[116] Microfiltration and ultrafiltration membranes are mainly used to separate microbial cells and macromolecular proteins for their subsequent recycling to ensure high cell concentration and high productivity. [117][118][119] With the expansion of the material market, some new solvents and fibers have been used in the preparation of microfiltration and ultrafiltration membranes. [120][121][122] Lu and colleagues established an external ceramic microfiltration system with a pilot-scale fermenter.…”

Dynamic Modeling Using Artificial Neural Network of Bacillus Velezensis Broth Cross-Flow Microfiltration Enhanced by Air-Sparging and Turbulence Promoter

“…The reason for this can be found in the rapid flux decline at the beginning of Bacillus velezensis broth microfiltration. Cultivation broth is a complex mixture of various components that can cause severe membrane fouling in the initial phase of microfiltration [8,11,14,16]. This contributes to reduced ANN prediction capabilities in this region.…”

“…Membrane separation processes such as microfiltration are gaining interest as an alternative to conventional separation processes and recently it has become the mainstream separation techniques used for cell harvesting and broth clarification [8]. Sustainability issues dominating today's industry have contributed to the shift from chemical synthesis processes to biotechnology production in numerous branches of industry, so the membrane-based separations have become very promising unit operations [9].…”

“…The cultivation broth is a complex mixture of whole microbial cells or cell debris, as well as residual medium components and various extracellular macromolecules. The decreasing pattern of microfiltration permeate flux during cultivation broth filtration is caused by numerous factors that can be evaluated by hydraulic resistance [8,11]. The hydraulic resistance associated with the cake build-up is the main factor influencing the microfiltration of cultivation broths [8,11,12].…”

“…The decreasing pattern of microfiltration permeate flux during cultivation broth filtration is caused by numerous factors that can be evaluated by hydraulic resistance [8,11]. The hydraulic resistance associated with the cake build-up is the main factor influencing the microfiltration of cultivation broths [8,11,12]. The reduction of cake layer, and consequently permeate flux improvement, can be achieved by applying flow alternations in a membrane channel [13][14][15][16][17].…”