Nanofiltration of sweet whey by spiral wound organic membranes: Impact of hydrodynamics

Romain Jeantet , Jesus Rodríguez , Anita Garem

The influence of permeation flux $J$ and wall shear stress $\tau_w$, on performances of the nanofiltration of concentrated sweet whey at volume reduction ratio 2, $18 ^\circ$C and using organic membranes was studied. It was concluded that sweet whey nanofiltration could be optimised through the parameter $J/\tau_w$, since $J$ and $\tau_w$ act together in a competing mechanism of convection/erosion at the membrane surface, that governs membrane fouling and selectivity. Hence, the overall fouling was strongly dependent on the ratio $J/\tau_w$, with a critical $J/\tau_w$ value of approximately 6.0. When $J/\tau_w < 6.0$, the total membrane fouling was relatively low and almost independent on operating conditions. For higher ratios of $J/\tau_w$, there was a spectacular increase in fouling and a very strong dependence between the fouling index and $J/\tau_w$. Simultaneously, selectivity was altered under these conditions, with higher retention of monovalent ions and lower retention of lactose. Finally, optimal hydrodynamic conditions were defined in the range 3-6. Under these conditions, longer operating times, lower chemical oxygen demand in permeate and higher demineralization could be expected at lower processing costs.

Mots clés: nanofiltration; hydrodynamic; sweet whey; fouling

Domaines: Alimentation et Nutrition; Ingénierie des aliments

Romain Jeantet, Jesus Rodríguez, Anita Garem. Nanofiltration of sweet whey by spiral wound organic membranes: Impact of hydrodynamics. Le Lait, 2000, 80 (1), pp.155-163. ⟨10.1051/lait:2000115⟩. ⟨hal-00895396⟩