摘要 |
In one embodiment, a system for treating a gas stream comprising NOx produced from a used or spent acid pickling solution includes a pickling apparatus, a first chamber, and a second chamber. The pickling apparatus includes an inlet adapted for introducing a reducing agent into contact with the acid pickling solution, wherein the reducing agent reacts with free nitric acid in the acid pickling solution to form NOx; and a headspace in which gas comprising NOx collects. The first chamber includes a first inlet communicating with the headspace, a second inlet communicating with a source of ozone, and an interior volume adapted to contact the NOx gas and the ozone. The second chamber may include a third inlet communicating with a source of water vapor, an interior volume adapted to contact the gaseous effluent from the first chamber with the water vapor introduced through the third inlet, and an outlet for collecting solubilized nitric acid from the interior volume of the second chamber. |