Process for electrolytically purifying a photographic developer waste solution
AssigneeThe Japan Carlit Co., Ltd.
InventorsReiichi Itai, Katsuyuki Murakami
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Abstract
A photographic developer waste solution is electrolytically purified by adding to said waste solution chloride ion and bromide ion; or chloride ion, bromide ion and iodide or iodate ion under limited pH, temperature, anode current density and current concentration conditions.
Claims9
A process for electrolytically purifying a photographic developer waste solution containing components having high COD values comprising adding to said waste solution three precursors to provide a concentration of from about 3 to about 60 grams of chloride ion, from about 3 to about 25 grams of bromide ion, and from about 0.08 to about 9 grams of iodide or iodate ion per liter of said waste solution, and subjecting the resulting waste solution to non-diaphragm electrolytic oxidation at a pH of 2 to 12, a temperature of 10.degree. to 100.degree. C., an anode current density of 2 to 40 amperes per square decimeter and a current concentration of 3 to 50 amperes per liter until said COD values are reduced.
In a process for electrolytically purifying a photographic developer waste solution containing components having high COD values, said components including metol, hydroquinone and phenidone as general developing agents, or a derivative of p-phenylene diamine as a color developing agent;
- a derivative of phenol or naphthol, or a compound contaning an active methylene group as a coupler;
- a sulfite antioxidant;
- an inorganic reducing substance, or formaldehyde, the improvement which comprises adding to said waste solution three precursors to provide a concentration of from about 3 to about 60 grams of chloride ion, from about 3 to about 25 grams of bromide ion, and from about 0.08 to about 9 grams of iodide or iodate ion perliter of said waste solution, and subjecting the resulting waste solution to non-diaphragm electrolytic oxidation at a pH of 2 to 12, a temperature of 10.degree. to 100.degree. C., an anode current density of 2 to 40 amperes per square decimeter and a current concentration of 3 to 50 amperes per liter, with the anode being selected from the group consisting of titanium, zirconium and tantalum plated with a platinum group metal or alloys of said platinum group metals, and applying the current to said waste solution until the impurities have been oxidized to a point where an acceptable COD concentration exists.
Dependencies are inferred from the claim text.