| 摘要 |
<p>PURPOSE:To enable long-term operation without changing function as a redox catalyst and without replenishing moisture, by using a solvent mixture consisting of water and a hardly volatile org. solvent compatible with water as the solvent of an iron chelate agent. CONSTITUTION:The lower part of a rotary screen B is immersed in a solution mixture E prepared by dissolving an iron-EDTA chelate in a liquid mixture consisting of a hardly volatile org. solvent having compatibility with water (e.g., ethylene glycol or propylene glycol) and water and dirty air A is passed through said screen B to remove noxious substances such as SO2, NOx or H2S in air. The solution mixture E absorbs moisture when humidity is high but evaporates moisture when humidity is low and there is no change in function as a redox catalyst and long-term operation can be performed without especially replenishing moisture.</p> |
