Document Type: Research Paper
The Tagouchi method was used for providing the instruction of ultra-filter dairy membrane cleaning. The goal function with using of four undimentionalized parameter, i.e., water and milk serum flux, percent of protein and dry mass of permeate, as quality indicator of cleaning of cleaned membrane, was defined. As a result, basic cleaning solution was found as follows: 0.8% NaOH, 1.0% EDTA, 1.0% Sodium di Hydrogen Phosphate, 0.1% Sodium Carbonate and 0.2% SDS. Cleaning with this solution at first step for 90 min and at second step for 20 min in 50°C was found suitable. The optimum acidic solution was obtained as 0.3% Nitric Acid, 0.01% Phosphoric Acid and 0.15% Marlophen. Cleaning with this solution for 60 min at 30°C has serious effect on membrane cleaning. In addition, using of lipase and protease in cleaning operation was studied. The results showed that protease is 4.39% stronger than lipase. It is shown that the serious effect of protein components is more than oily components on fouling of dairy membrane.