Dairy by-products valorization with biomethane and biohydrogen production through lactose fermentation in AnMBR

Dairy liquid by-products after cheese production (e.g. whey for hard cheese, “scotta” for ricotta, brine for mozzarrella, lactose syrup after milk standardization by ultrafiltration) represent a potential revenue for food factories where large scale industrial production is implemented, as additional ingredients may be recovered, transformed and sold as separate products. Still, these by-products may also represent a problem for small/medium size factories or in areas that are far from ingredients transformation platforms: complete processing of smaller volumes or shipping liquids over long distances is not convenient. By-products are often disposed as waste, generating unproductive cost for the factory and worsening environmental footprint. In this paper a simple closed loop solution is evaluated for full valorization of those by-products, based on the technologies of: protein separation/concentration and anaerobic treatment of the lactose containing permeate.