Possibilities for the use of membrane processes for the pre-treatment of wastewater from the production of dried potato puree

摘要

Our research focused on the membrane separation of wastewater resulting from the production of dried potato puree. Our aim was to investigate possibilities for recycling obtained retentate back to the actual production process, and, consequently, for reducing wastewater pollution. This paper describes trials of MF and RO membrane filtration of starch wastewater. The treated water contained starch, in either granulated or gelatinized form, and solids (fine pieces of potato skins). The trials were conducted in either one or two stages. We used a pilot plant equipped with a ceramic membrane with a filtration area of 0.35 m~2 and pore sizes of 500 and 100 nm. We also tested an organic RO membrane (7410) in the laboratory. High permeate flux above 1001/(m~2h) was measured for the 100 nm membrane, but with considerable fouling. Filtration through this membrane resulted in high COD and BOD_5 rejection (approximately 60%), an effect which was increased by the subsequent RO filtration. The content of soluble carbohydrate, 0.011% in permeate (with 0.44% dry substance), was analyzed using high-performance anion-exchange chromatography coupled with pulsed amperometric detection.