Cross-flow filtration of fruit juice

8. Chemical cleaning

The filtration system and the filters were rinsed with distilled UF water after each filtration test. Two cleaning procedures were tested with polymeric membranes from X-flow.

The first cleaning procedure was based on a combination of two cleaning agents supplied by Scan Diversey (Divos 2 S and Divos 124). Divos 2S is a strong acid liquid cleaning agent based on H₃PO₄ and it is used to remove inorganic contaminates. Divos 124 is a strong alkaline liquid cleaning agent based on KOH, tetrasodium-EDTA and anionic tensed, and it is used to emulsify fat and proteins. This procedure did not recover successfully the polymeric membranes.

The second cleaning procedure was based on a combination of several cleaning agents supplied by Henkel-Ecolab. The cleaning procedure is described in the section on Microfiltration of Cherry Juice with Polymeric Membranes. The agents used had different functions, i.e., emulsification and degradation of fat and proteins, disinfection, removal of fat and inorganic particles, etc. Better results were obtained with this cleaning procedure. However, the results were not optimal and the membranes could not be completely recovered.

In order to get some comparable and concluding results from the different filtration tests, a new filter was used for each experiment.