Study on Chemical Removal of Nitric Oxide (NO) as a Main Cause of Fine Dust (Air Pollution) and Acid Rain

Abstract

This study was conducted to remove NO x , which is the main cause of fine dust and air pollution as well as acid rain. NO x was tested using 3% NO (diluted in He) as a simulated gas. Experiments were sequentially carried out by oxidizing NO to NO 2 and absorbing NO 2. Especially, we focused on the changes of NO oxidation according to both oxidant (NaClO 2) concentration change (1~10 M) and oxidant pH change (pH = 1~5) by adding HCl. In addition, we tried to suggest a method to improve NO 2 absorption by conducting NO 2 reduction reaction with reducing agent (NaOH) concentration (40~60%). It was found that NO removal efficiency increased as both concentration of oxidant and flow rate of NO gas increased, and NO decreased more effectively as the pH of hydrochloric acid added to the oxidant was lower. The NO 2 adsorption was also better with increasing NaOH concentration, but the NO removal efficiency was ~20% lower than that of the selective NO reduction. Indeed, this experimental method is expected to be a new method that can be applied to the capture and removal of fine dust caused by air pollution because it is a method that can easily remove NO gas by a simple device without expensive giant equipment.