Abstract: The present invention concerns a process and a device for the separation of substances dissolved in the washing waters used in a processing bath for a photographic film.The photographic film, after passing through the processing bath, is caused to pass successively through at least two washing tanks, the process consisting of causing the waste water from the washing baths to circulate through a nanofiltration membrane device, the permeate from the said nanofiltration device being recirculated to the washing tank or tanks other than the last of the tanks in which the film passes, the last of the tanks being fed with clean water from an auxiliary source.

Abstract: The present invention relates to an electrolytic desilvering method for photographic effluents.This method is carried out in an electrolytic cell comprising at least one anodic compartment and at least one cathodic compartment. The photographic effluent is treated in the cathodic compartment of the cell in order to reduce the silver ions in solution. The electrolyte is then recycled in the anodic compartment before being discharged to the sewer.This recycling in the anodic compartment allows to discharge to the sewer an effluent having a silver content less than 20 ppm.

Abstract: The present invention relates to an electrolytic device.The electrolytic device comprises at least one porous stirring electrode associated with at least one counter-electrode, as well as a method for treating the effluents with this device.These electrolytic device and method can be applied, for example, to the recovery, the recycling and the purification, in concentrated or dilute solution, of compounds exhibiting redox properties. The efficiency of the electrolytic device is clear in FIG. 3, which shows the amount of silver recovered with the electrode of the invention (3b) and with a non-stirring electrode (3a).