Toward a Sustainable\nApproach for Dairy Waste Management:\nThe Integration of Filtration, Ion Exchange, and Electrodialytic Processes\nfor Whey Demineralization

The\ndisposal of salt-rich waste streams, such as salty\nwhey, remains\nan intractable issue in the dairy industry, as there is no environmentally\nacceptable mechanism for the disposal of sodium chloride. In this\nwork, two different processes are integrated at a pilot scale to provide\na solution. Electrodialysis with bipolar membranes (EDBM) is used\nto convert sodium chloride in salty whey into sodium hydroxide (NaOH)\nand hydrochloric acid (HCl). The HCl generated from this EDBM operation\nis then utilized directly during the electrodialysis (ED) of sweet\nwhey to prevent scaling, for the production of demineralized whey\n(D70). The HCl and NaOH produced from the EDBM are also used in the\nclean-in-place procedures of the pilot plant. This novel integration\nenables the recovery of both byproducts as valuable resources. No\nsignificant fouling is noted in either EDBM or ED studies, illustrating\nthe satisfactory quality of the chemicals produced for onsite consumption.\nThe inclusion of an upstream ion exchange step also improves the ED\ncurrent efficiency from 69 to 85% for a 90% reduction in sweet whey\nconductivity, with no significant change in ED energy consumption.