A Novel Method Based on Hydrodynamic Cavitation for Improving Nitric Oxide Removal Performance of NaClO2

Liguo Song; Yuhang Wei; Chengqi Deng; Jingang Yang; Hao Sui; Feng Guo; Lingrun Meng; Xingda Zhao; Shiping Wei; Deping Sun; Zhitao Han; Minyi Xu; Xinxiang Pan

doi:10.3390/ijerph20043684

A Novel Method Based on Hydrodynamic Cavitation for Improving Nitric Oxide Removal Performance of NaClO₂

Int J Environ Res Public Health. 2023 Feb 19;20(4):3684. doi: 10.3390/ijerph20043684.

Authors

Liguo Song^{1

2}, Yuhang Wei¹, Chengqi Deng¹, Jingang Yang¹, Hao Sui¹, Feng Guo¹, Lingrun Meng¹, Xingda Zhao¹, Shiping Wei¹, Deping Sun¹, Zhitao Han^{1

2}, Minyi Xu^{1

2}, Xinxiang Pan³

Affiliations

¹ Marine Engineering College, Dalian Maritime University, Dalian 116026, China.
² Liaoning Research Center for Marine Internal Combustion Engine Energy-Saving, Dalian 116026, China.
³ School of Electronics and Information Technology, Guangdong Ocean University, Zhanjiang 524088, China.

Abstract

In the removal of nitric oxide (NO) by sodium chlorite (NaClO₂), the NaClO₂ concentration is usually increased, and an alkaline absorbent is added to improve the NO removal efficiency. However, this increases the cost of denitrification. This study is the first to use hydrodynamic cavitation (HC) combined with NaClO₂ for wet denitrification. Under optimal experimental conditions, when 3.0 L of NaClO₂ with a concentration of 1.00 mmol/L was used to treat NO (concentration: 1000 ppmv and flow rate: 1.0 L/min), 100% of nitrogen oxides (NO_x) could be removed in 8.22 min. Furthermore, the NO removal efficiency remained at 100% over the next 6.92 min. Furthermore, the formation of ClO₂ by NaClO₂ is affected by pH. The initial NO_x removal efficiency was 84.8-54.8% for initial pH = 4.00-7.00. The initial NO_x removal efficiency increases as the initial pH decreases. When the initial pH was 3.50, the initial NO_x removal efficiency reached 100% under the synergistic effect of HC. Therefore, this method enhances the oxidation capacity of NaClO₂ through HC, realizes high-efficiency denitrification with low NaClO₂ concentration (1.00 mmol/L), and has better practicability for the treatment of NO_x from ships.

Keywords: NaClO2; exhaust gas treatment; hydrodynamic cavitation; ship; wet removal of NO.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Hydrodynamics
Nitric Oxide*
Nitrogen Oxides
Oxidation-Reduction
Sulfur Dioxide*

Substances

Nitric Oxide
Sulfur Dioxide
Nitrogen Oxides

Grants and funding

This work is financially supported by the National Natural Science Foundation of China (Grant No. (52071046, 51709029, 52271356)), Dalian Science and Technology Innovation Foundation (Grants No. 2021JJ12GX028), Guangdong Province Natural Resources Project (2022−32).