Clean Technology for Treatment of Photographic Wastes and Silver Recovery

Abstract

Photographic industry which is extensively used by the medical and film industries heavily depend on silver. The industry produce large quantities of wastewater containing high concentrations of silver compounds. Silver in all forms is regarded as toxic heavy metal and prohibited from discharging into public sewers. Also silver is an expensive commodity and recovery of silver from these wastewaters and recycling improves production cost. Thus makes the process an environmentally friendly operation. This paper gives an insight of an improved silver extraction process developed at the building department of Ngee Ann Polytechnic to effectively recover silver from photographic wastes and to treat the waste water to standards acceptable for disposal, by the Ministry of the Environment.