Flux Improvement during Cross-flow Microfiltration of Wheat Starch Suspension using Turbulence Promoter

Abstract

The objective of this study was to investigate the effects of the process variables (transmembrane pressure, flow rate, and concentration) on the permeate flux during the microfiltration of model starch suspensions, and to determine the conditions under which the use of Kenics statics mixer as a turbulence promoter is justified. A response surface methodology was used to examine the influence of the selected operating conditions on starch suspension microfiltration using a single channel ceramic membrane with 200 nm pore size. The experimental results clearly show that the improved performance of starch suspension cross-flow microfiltration can be obtained by using a Kenics static mixer, especially at lower flow rates. Compared to the operation without the turbulence promoter, the average permeate flux improvement during the filtration period ranged from 30% to 230%. As a result of the statistical analysis, the optimal conditions for starch suspension microfiltration were determined and applied to microfiltration of starch industry wastewater.

Keywords:

• cross-flow microfiltration
• response surface methodology
• starch suspension
• static mixer

ACKNOWLEDGEMENTS

The authors wish to express their sincere gratitude to the Ministry of Science and Technological Development of the Republic of Serbia for its financial support (Project Number: TR-31002).

Notes

Note: TMP-transmembrane pressure, Q-suspension flow rate, C-suspension concentration, J_NSM-average permeate flux without static mixer, J_SM-average permeate flux with static mixer, FI-permeate flux improvement.

Note: J_NSM-average permeate flux without static mixer, J_SM-average permeate flux with static mixer, FI-permeate flux improvement.1-transmembrane pressure; 2-suspension flow rate; 3-suspension concentration.

Note: J_NSM-average permeate flux without static mixer, J_SM-average permeate flux with static mixer, FI-permeate flux improvement. DF-degree of freedom, SS-sum of squares, MS-mean squares.

Note: TMP-transmembrane pressure, Q-suspension flow rate, C-suspension concentration, J_NSM-average permeate flux without static mixer, J_SM-average permeate flux with static mixer, FI-permeate flux improvement, ER-reduction of specific energy consumption.