Decomposition of 3,5-dinitrobenzamide in aqueous solution during UV/H2O2 and UV/TiO2 oxidation processes.

Abstract

3,5-Dinitrobenzamide has been widely used as a feed additive to control coccidiosis in poultry, and part of the added 3,5-dinitrobenzamide is excreted into wastewater and surface water. The removal of 3,5-dinitrobenzamide from wastewater and surface water has not been reported in previous studies. Highly reactive hydroxyl radicals from UV/hydrogen peroxide (H2O2) and UV/titanium dioxide (TiO2) advanced oxidation processes (AOPs) can decompose organic contaminants efficiently. In this study, the decomposition of 3,5-dinitrobenzamide in aqueous solution during UV/H2O2 and UV/TiO2 oxidation processes was investigated. The decomposition of 3,5-dinitrobenzamide fits well with a fluence-based pseudo-first-order kinetics model. The decomposition in both two oxidation processes was affected by solution pH, and was inhibited under alkaline conditions. Inorganic anions such as NO3-, Cl-, SO42-, HCO3-, and CO32- inhibited the degradation of 3,5-dinitrobenzamide during the UV/H2O2 and UV/TiO2 oxidation processes. After complete decomposition in both oxidation processes, approximately 50% of 3,5-dinitrobenzamide was decomposed into organic intermediates, and the rest was mineralized to CO2, H2O, and other inorganic anions. Ions such as NH4+, NO3-, and NO2- were released into aqueous solution during the degradation. The primary decomposition products of 3,5-dinitrobenzamide were identified using time-of-flight mass spectrometry (LCMS-IT-TOF). Based on these products and ions release, a possible decomposition pathway of 3,5-dinitrobenzamide in both UV/H2O2 and UV/TiO2 processes was proposed.

• Authors: Yingjie Yan, Qi-Nan Liao, Feng Ji, Wei Wang, Shoujun Yuan, Zhen-Hu Hu
• Journal: Environmental science and pollution research international (Environ Sci Pollut Res Int) Vol. 24 Issue 6 Pg. 5360-5369 (Feb 2017) ISSN: 1614-7499 [Electronic] Germany
• PMID: 28013465 (Publication Type: Journal Article)

Chemical References

• Benzamides
• Waste Water
• Water Pollutants, Chemical
• titanium dioxide
• Hydroxyl Radical
• nitromide
• Hydrogen Peroxide
• Titanium

Topics

• Benzamides
• Hydrogen Peroxide
• Hydroxyl Radical
• Kinetics
• Oxidation-Reduction
• Titanium
• Ultraviolet Rays
• Wastewater (analysis)
• Water Pollutants, Chemical
• Water Purification (methods)