Water scarcity is a serious issue and a concern for the dairy industry as declines in the availability of water could decrease the food supply and increase food prices. Water is necessary for many applications, including equipment cleaning, which can use 1-60 liters of water per kilogram of processed milk.

Given the amount of water needed and concerns regarding resource scarcity, researchers from the University of Nebraska-Lincoln sought to find a method to recycle and reuse water from whey for clean-in-place systems. Their findings provide scientific evidence of the safety of reusing reconditioned water in food processing plants, contributing to building a culture of water conservation and sustainable production throughout the food supply chain.

Current regulations indicate that only potable water may be used to clean food contact surfaces and equipment surfaces, but reconditioning and reusing water is a promising alternative that is currently acceptable for initial cleaning of fruits and vegetables as well as scalding of meat and poultry.

In their study, recently published in the Journal of Dairy Science, Nebraska researchers Yulie Meneses and Rolando Flores tested wastewater from the whey of cheddar cheese by subjecting it to reverse osmosis and ultrafiltration, as well as an additional step of spray-drying. The resulting reconditioned water was used to clean stainless steel surfaces that had a biofilm, with promising results shown for both bacterial counts and scanning electron microscopy analysis.

“Using the combined ultrafiltration and reverse-osmosis system, 47% of water can be recovered from whey,” Meneses said.

“This demonstrates the viability of our method for wastewater, as the cleaning efficiency was comparable to potable water in clean-in-place systems,” Flores added.

Further, by incorporating spray-drying and condensation into the process, recovery of additional water can be achieved; after suitable treatment, that water could also be used in cleaning applications or other activities with high water demand.

“Sustainable production and manufacturing is a priority for the dairy industry. This new research demonstrates that an unwanted byproduct of dairy manufacturing (whey) can be processed to generate clean water, saleable food and additional revenue for dairy manufacturers,” Journal of Dairy Science editor-in-chief Matt Lucy said.

Because of its potential in terms of revenue and conserving natural resources, these wastewater reclamation techniques are highly interesting, Lucy added. More research is required, however, to further elucidate risks and broader environmental issues as they relate to the techniques in this study.

The Journal of Dairy Science, the official journal of the American Dairy Science Assn., is co-published by Elsevier and FASS Inc. for the American Dairy Science Assn., an international organization of educators, scientists and industry representatives who are committed to advancing the dairy industry.