Application of turbulence promoter in protein recovery from food wastewater by dynamic shear enhanced ultrafiltration

Abstract

The expected growth of membrane technology in protein recovery from wastewater is largely impeded by operational non-idealities like concentration polarization and membrane fouling. Two independent concepts, namely, the Dynamic Shear Enhanced (DSE) filtration and turbulence promoters were introduced decades earlier to remediate the problems. However, no systematic effort was undertaken to explore the synergy of the two process intensification schemes. In this study, we have investigated the effects of simple wire-type turbulence promoter on a specific class of DSE membrane modules, the spinning basket filtration units. The maximum flux improvement with synthetic wastewater (i.e., Bovine Serum Albumin (BSA)-water solution) was 445%, whereas for the real dairy effluent, the respective enhancement levelled off at 204%. The lower level of flux enhancement for real wastewater may be attributed to the severe fouling caused by the casein micelle. The increase of power consumption in all promoter-fitted configurations was limited to 9% only. Thus, turbulence promoter-integrated spinning basket group of membrane modules are confirmed to be much superior relative to other devices in protein recovery from wastewater. Our results are also supported by corroborating computational fluid dynamic (CFD) simulations of elevated shear and high turbulent kinetic energy dissipation rates for all promoter-fitted configurations. The present outcomes clearly recommend the application of turbulence promoters in DSE modules to maximally increase the protein recovery from wastewater even at concentrations where the standard cross-flow systems are apprehended to be non-functional.