Kinetic Modeling of Permeates Flux and Total Hydraulic Resistance of Camel Milk Diafiltration: Effect of pH and NaCl Concentration

Abstract

In this study, kinetic modeling of permeates flux and total hydraulic resistance of camel milk diafiltration in different conditions of pH (5.8, 6.3 and 6.8) and NaCl concentration (0, 75 and 150 mM) was performed by using 6 kinetic models. Finally, the homographic kinetic model has been selected for modeling permeates flux and exponential kinetic model has been selected for modeling total hydraulic resistance considering coefficient of determination (R2) and Root mean square deviation (RMSE). The results of ANOVA of homographic kinetic model illustrated that the linear effect of pH on all model parameters (initial flux (J0), steady-state flux (J∞), flux decline time constant (1/b) and flux decline extent (a)) and the linear effect of NaCl concentration at a 95% level on J0, 1/b and the interaction effects of pH-NaCl concentration at a 99% level on a were significant. The results of ANOVA of exponential kinetic model also showed that the linear effect of pH had a significant effect on steady-state hydraulic resistance (R∞) and the linear effect of NaCl concentration on initial hydraulic resistance (R0), R∞ and resistance increment rate (K) and the interaction effects of pH-NaCl concentration at a 95% level on k were significant. According to the results of sensitivity analysis for each 0.1 increase in pH about 1% R∞ decreased and for each 10 mM increase in NaCl concentration 2.75% R0 and 9% 1/b of the samples increased.

Keywords

• camel milk
• diafiltration
• flux
• hydraulic resistance
• kinetic modeling