Integrating Whey Processing: Ultrafiltration, Nanofiltration, and Water Reuse from Diafiltration

Area of Science:

• Food Science and Technology
• Chemical Engineering
• Environmental Science

Background:

• Whey processing generates significant wastewater, posing environmental and economic challenges.
• Current methods for whey protein concentrate (WPC) and lactose production often involve water-intensive purification steps like diafiltration (DF).
• Efficient water recovery is crucial for sustainable dairy refinery operations.

Purpose of the Study:

• To develop an integrated process for producing WPC and lactose while simultaneously recovering water from DF permeate.
• To evaluate the quality of reclaimed water and its suitability for reuse in WPC production.
• To demonstrate the economic and environmental benefits of water recycling in whey processing.

Main Methods:

• Ultrafiltration and nanofiltration were employed for concentrating whey protein and lactose.
• Diafiltration (DF) was used for purification, followed by water reclamation using reverse osmosis and activated carbon adsorption.
• Reclaimed water quality was assessed, and its efficacy in a subsequent WPC production batch was tested.

Main Results:

• High-purity whey protein concentrate (88% protein) and lactose (90% purity) were produced.
• Approximately 66% of the water from the DF step was successfully reclaimed to drinking water standards.
• Reused reclaimed water did not compromise the quality of the subsequently produced WPC batch.

Conclusions:

• The proposed integrated process enables efficient co-production of WPC and lactose with substantial water recovery.
• Reclaimed water is suitable for reuse in WPC manufacturing, reducing freshwater dependency.
• This approach offers a sustainable solution for dairy refineries, addressing water scarcity and improving resource utilization.