Advanced oxidative degradation of monoethanolamine in water using ultraviolet light and hydrogen peroxide

Abstract

This study aims to develop a benign and commercially viable method for the degradation of monoethanolamine (MEA) in the aqueous phase via an ultraviolet/hydrogen peroxide (UV/H₂O₂) advanced oxidation process (AOP). The current investigation is novel in terms of detailed kinetic analysis and degradation mechanisms; the impact of pH and UV light intensity on MEA degradation was thoroughly examined. pH 9 was identified as the optimal condition, achieving a degradation efficiency of 76.28%, while the highest UV light intensity of 59.055 mJ cm⁻² resulted in an 85.13% degradation efficiency. A comprehensive kinetic study highlighted the reaction rates under varying conditions, providing valuable insights and dynamics of the degradation. The mechanistic pathway of MEA breakdown, identified using Liquid Chromatography Mass Spectrometry (LCMS) analysis revealed ethylene glycol, glycolaldehyde, glycine aldehyde, glycine, carbon dioxide, and ammonium ions as the primary degradation products. These results provide both operational insights and a greater understanding of the degradation mechanism, demonstrating that UV/H₂O₂ AOP offers an effective and environmentally benign solution for MEA degradation. The findings make a substantial contribution to the development of MEA treatment methods that are both economically viable and sustainable.