Recovery of lactose from aqueous solution by application of ultrasound through millichannel

Abstract

Abstract Instead of direct disposal of whey, extraction of valuable products from it may reduce the environmental pollution. In the present study, the effect of ultrasound irradiation through millichannel on recovery of lactose was investigated. The ultrasonic baths of varying amplitude (20–40%) and frequency (25–35 kHz), two different configurations of millichannel i.e., coil and serpentine, were used to know their individual and combined effect on the lactose yield. Box-Behnken design was employed to examine the interactive effect of different operating conditions. The recovery of lactose was enhanced approximately by 5–53% and induction time was reduced by 1.79–1.85 times in comparison to the conventional process. The size of the lactose crystals was reduced from 139.5 to 42.486 μm at 40% amplitude and 49.879 μm at 35 kHz frequency. Optimized condition showed 63% yield of lactose at 3.6 supersaturation, 35 kHz frequency, and 45 min of sonication time.