Energy efficient turbulence promoter flux-enhanced microfiltration for the harvesting of rod-shaped bacteria using tubular ceramic membrane

Cross-Flow Microfiltration of Glycerol Fermentation Broths with Citrobacter freundii

“…In turn, number of bacteria in the feed was in the range between 3.55 × 10 7 and 5.48 × 10 9 CFU/mL. The same order of magnitude of CFU/mL in various bacterial suspensions clarified by cross-flow MF systems with ceramic membranes has been reported in previous studies [5,7,11,16,19,20,23] (Table A1). In the fermentation broths, a sediment has been observed and the total wet biomass has been determined in the range 5.06 and 10.08 g/dm 3 .…”

“…Table A1, Appendix A summaries literature review related to the cross-flow MF of bacterial suspensions by using ceramic membranes. It indicates that microfiltration process is becoming increasingly attractive in the biotechnology industry in order to obtain a clarified filtrate from various bacterial products such as skim milk [1][2][3][4][5][6], skimmed colostrum [7], gum arabic suspension [8], cell suspension [9][10][11][12], fermentation soy sauce [13,14], and fermentation broths [15][16][17][18][19][20][21][22][23][24][25]. It has to be pointed out that with regard to complex media such as fermentation broths, microfiltration is proposed as a pre-treatment stage for the final separation by nanofiltration (NF) or reverse osmosis (RO) processes with spiral-wound modules [26].…”

“…This causes in increasing operational costs and reduces a membrane's lifetime [33][34][35][36]. Based on literature review, it can be analyzed that flux decline during MF of biological suspensions is affected by a great number of factors, such as: (i) process parameters (transmembrane pressure, feed flow rate, and temperature) [1,2,4,6,12,16,[18][19][20][21][22][23]25,37,38], (ii) membrane properties (pore size and its distribution, hydrophilicity/hydrophobicity character) [1,3,6,14,21,25,37,39], (iii) feed solution properties (nature, bacterial cell mass, particle size, and pH) [11,12,21,22,38], and (iv) interaction between foulants and membranes [3,22]. It should be mentioned that these interactions are often unknown or not understood at the fundamental level [40].…”

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

“…The presence of the Kenics turbulence promoter (SM mode) resulted in a significant increase of flux value (around 300%) for selected experimental conditions depicted in Figure 3. The characteristic shape of the mixer that intensifies radial mixing in the membrane channel and reduces the cake thickness is a probable reason for this [13][14][15]. Combination of the static mixer and two-phase flow (AS + SM mode) resulted in the highest flux values, although the contribution of air-sparging is less compared to the static mixer.…”

“…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].…”