PURPOSE: To facilitate the treatment of a used photographic processing soln. by which the amt. of a waste soln. having high load on environmental pollution is reduced and water necessary for photographic processing can be ensured without generating a malodor.

CONSTITUTION: A used photographic processing soln. is concd. by evaporation and the resulting distillate is used as, water for dissolving a photographic processing agent or water for compensating evaporation or for replenishment added to the processing tank of an automatic processing machine. The used photographic processing soln. contains thiocyanate and thiosulate in ≥1/25 weight ratio.