title: Direct contact membrane distillation for the concentration of saline dairy effluent.
abstract: The ability of direct contact membrane distillation to concentrate the waste effluent from salty whey, a by-product from the cheese making industry has been investigated. The effect of trace protein in the feed, cross-flow velocity and feed acidity were the factors examined. Flat Sheet PTFE membranes of nominal pore sizes 0.05, 0.22 and 0.45 μm were utilised. A decline in feed flux in the presence of trace protein in the feed was observed, but liquid penetration through the membrane could still be prevented by utilization of a membrane of smaller pore size, to achieve a final total solids concentration of ±30% w/w with water recovery from 37 to 83 %. The pressure-drop across the channel length was also predicted accounting for the feed spacer. To increase the channel length up to 1 m will require operation using the smallest pore size of 0.05 μm, unless very low cross-flow velocities are used. The fouling of the membrane is primarily governed by precipitation of a calcium phosphate salt. However, operation at low pH does not improve the flux or the final salt concentration significantly.
authors.affiliation: Dairy Innovation Research Hub, Department of Chemical and Biomolecular Engineering, The University of Melbourne, VIC, 3010, Australia.
authors.forename: Kezia
authors.initials: K
authors.lastname: Kezia
authors.affiliation: Dairy Innovation Research Hub, Department of Chemical and Biomolecular Engineering, The University of Melbourne, VIC, 3010, Australia.
authors.forename: Judy
authors.initials: J
authors.lastname: Lee
authors.affiliation: Dairy Innovation Research Hub, Dairy Innovation Australia Limited, 180 Princes Hwy, Werribee, VIC, 3030, Australia.
authors.forename: Mike
authors.initials: M
authors.lastname: Weeks
authors.affiliation: Dairy Innovation Research Hub, Department of Chemical and Biomolecular Engineering, The University of Melbourne, VIC, 3010, Australia. Electronic address: sandraek@unimelb.edu.au.
authors.forename: Sandra
authors.initials: S
authors.lastname: Kentish
mesh_terms: D002611:Cheese; D057168:Distillation / Q000379:methods*; D005374:Filtration / Q000379:methods*; D005525:Food-Processing Industry; D007220:Industrial Waste; D008567:Membranes, Artificial; D008894:Milk Proteins / Q000737:chemistry; D011312:Pressure; D054712:Salinity; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D007220:Industrial Waste; D008567:Membranes, Artificial; D008894:Milk Proteins; D062065:Wastewater
keywords: Dairy salts; Fouling; Membrane distillation; Pressure drop