Cost effective potentiostatic control unit for recovery of silver from photographic fixer solution

Photographic fixture solution originates from the processing of black and white photographic films and the silver concentration in the fixer is around 2 to 8 gl-1. Due to over increasing cost of silver and very stringent pollution regulations, it makes one to recover silver from the fixer solution which is a good secondary source for silver. Normally during the silver recovery from fixer in galvanostatic mode, current has to be decreased with respect to silver concentration in fixer for avoiding sulphide formation. In order to achieve this a cost effective potentiostatic control unit is employed for silver recovery which will make the current to decrease due to decreasing silver concentration in the fixer solution. In this paper the effect of cathode potential and the effect of silver concentration on silver recovery from fixer solution using the cost effective potentiostatic control unit are studied and the results are reported