| 摘要 |
PURPOSE:To efficiently remove effensive odor by maintaining waste liquid from photographic process in a specified pH region, heating, evaporating and concentrating it. CONSTITUTION:Waste liquid contg. thiosulfate ion and silver ion or the like is fed to an evaporation tank 3. A pH regulating agent is fed to the evaporation tank 3 from a pH regulation tank 10 according to necessities and the pH is regulated to 3.0-11.0 In this state, waste liquid is heated, evaporated and concentrated. In this case, heating temp. is regulated with a temp. controller TC and vapor is heat-exchanged with waste liquid by a preheater 2 and sent to a gas cooler 6, cooled and its humidity is controlled, and the distillate is separated and stored in a distillate tank 8. Offensive odor is not felt for the gas separated from the distillate and this gas is discharged to the outside of the system. Thereby the load of secondary treatment can be decreased. |
