A review on processes for whey and dairy wastewater treatment and valorization

The dairy industry generates a significant amount, around 150 million tons, of losses and wastes. Particularly, whey requires treatment due to their high nutrient content and therefore, its facility to pollute. This treatment also allows its revalorization. Among the main processes that have been reported are the biochemical ones, where anaerobic fermentation is used to produce ethanol, biological processes with microalgae, for the production of fatty acids and some chemicals, and other processes, such as physical or enzymatic. If these processes are integrated, a biorefinery can be designed where the objective is to obtain a diversity of products from a biomass. Some approaches, to the use of dairy wastes in a biorefinery scheme, were reviewed. There is one biological treatment, insects, which have become of interest due to their high conversion efficiency and wide variety of products, such as protein, biofuels or chemicals, generated from waste. Specifically, black soldier fly larvae have been considered for waste degradation. Based on their advantages, the use of insects in a biorefinery scheme using dairy waste as feedstock was proposed.