The dairy industry is one of the most polluting industries in the food sector, with very high energy and water consumption demands. Dairy wastewater treatment is therefore mandatory to reduce its environmental impact and to allow water recycling and energy savings. In this work, retentates (concentrated lactose streams) obtained from dairy wastewater processed by nanofiltration or reverse osmosis were assessed for direct bioethanol production by lactose-fermenting yeasts. Two of the tested Kluyveromyces strains efficiently fermented all available lactose, with ethanol yields higher than 90% of the theoretical maximum (>0.47 g/g yield). A K. marxianus strain was selected that under severe oxygen-limiting conditions was able to reach 70 g/L (8.9 % v/v) of ethanol, which is compatible with energy-efficient distillation processes. The process here described for handling dairy wastewaters, making use of membrane technology, allows water recycling from the permeate, complying with legislation for drinking water, and simultaneous bioenergy (bioethanol) production from the retentate, therefore contributing to a more sustainable dairy industry.
|Status||Udgivet - dec. 2019|
|Begivenhed||MICROBIOTEC'19 - University of Coimbra, Coimbra, Portugal|
Varighed: 5 dec. 2019 → 7 dec. 2019
|Lokation||University of Coimbra|
|Periode||05/12/2019 → 07/12/2019|