Current Treatment Technologies of Cheese Whey and Wastewater by Greek Cheese Manufacturing Units and Potential Valorisation Opportunities

In the present study, recording and evaluation of the current practices applied for the treatment of wastewater and cheese whey, derived from ten cheese manufacturing units in Greece, was performed. Wastewater from cheese manufacturing includes milk losses, wastewater generated by the staff and by the washing of equipment, floors and milk transferring vehicles. Based on the study, cheese whey is separately collected from the cheese manufacturing wastewater in almost all the Greek units under study. Wastewater generated by Greek medium size units is mainly treated through the extended aeration activated sludge process, while wastewater derived from small size units is either disposed in the sewage system or it is stored until its transportation for further treatment. Moreover, aiming at revealing the potential exploitation opportunities, a comprehensive literature review on cheese whey valorisation technologies was also conducted. The literature review revealed that cheese whey and whey components can be used in a wide range of applications, mainly in the food and nutraceutical industry, as they contain several beneficial compounds that can be exploited. In this context, the increasing consumer concerns related to health and wellbeing have enhanced the acceptability and demand for whey products, such as the whey protein concentrates and isolates, the whey powder, the reduced lactose whey, etc. Moreover, cheese whey can be used for the production of sustainable energy alternatives to fossil fuels, such as ethanol, hydrogen and biogas. Among them, biogas production through anaerobic digestion could be a viable solution since relevant economic analysis revealed that this technology is a profitable and sustainable investment for a Greek cheese whey factory.