Bio-desulfurization device and desulfurization treatment method

摘要

PURPOSE: To maintain the concentration of sulfuric acid in a culture liquid at a constant level and, at the same time, a stable desulfurization performance over a long time by providing a nutritive salt recycling tank and removing sulfuric acid generated through a desulfurization reaction. CONSTITUTION: A gas containing hydrogen sulfide is supplied to a microbial treatment tank 3 for desulfurization oxidizing it into sulfuric acid by a microbial action. Next, the concentration of sulfuric acid in a culture liquid in the microbial treatment tank 3 is detected during the desulfurization process. When the concentration of sulfuric acid exceeds a specified level, a part of the culture liquid is taken out and is sent to a nutritive salt recycling tank 6. In the tank 6, calcium carbonate is added to this culture liquid with a high sulfuric acid concentration, then generated gypsum is separated, and the culture liquid after the removal of sulfuric acid is returned to the microbial treatment tank 3. Thus, the concentration of sulfuric acid in the culture liquid is maintained at a constant level and, therefore, a stable desulfurization performance over a long period of time is ensured. In addition, the addition of inorganic nutritive salts need no longer be required and cost required for the salts is curtailed.