✍ Scribed by Romas Ragauskas; Jurgita Matulionytė; Tomas Vengris; Audrius Padarauskas
No coin nor oath required. For personal study only.
An attempt to regenerate an exhausted photographic fixer solution, removing the surplus silver and bromide ions has been made. The ions were removed by electrolysis in a cell containing separate anionic and cationic compartments using ion exchange membranes. Four types of anion exchange membranes in two‐ and three‐compartment cells were used: AMX, ACS (Neosepta, Japan), AMI‐7001 (Ultrex^™^, USA), and MA‐40 (PO Stchekino, Russia). Silver deposition occurred at the titanium rotating cylinder cathode and the deposits were compact and bright. The residual silver ion concentration after electrolysis was 0.012–0.014 mol dm^−3^. Of the four membranes tested the ACS membrane was the most selective for removal of bromide ions. The current efficiency of bromide ion migration through the ACS membrane was approximately two to five times greater than that achieved with AMX, AMI‐7001 and MA‐40 membranes. After five regeneration cycles the fixer's working quality did not noticeably deteriorate. Copyright © 2004 Society of Chemical Industry
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