Mineralization of N‐Methyl‐2‐Pyrrolidone by UV‐Assisted Advanced Fenton Process in a Three‐Phase Fluidized Bed Reactor

Abstract

N‐Methyl‐2‐pyrrolidone (NMP), a commonly used solvent in industries, is treated with zero‐valent iron (Fe0) and hydrogen peroxide (H2O2) under UV irradiation. The reaction is carried out in a three‐phase fluidized bed reactor to ensure the smooth and continuous circulation of the Fe0 powder. The results reveal that NMP can be efficiently mineralized by UV‐assisted Fe0/H2O2 process (advanced photo‐Fenton process) with aeration. The mineralization process is properly fitted with the pseudo‐first order kinetics (R2 > 0.93). To determine the optimum conditions for NMP mineralization, the effects of pH, Fe0 dosage, H2O2 concentration, and initial NMP concentration are investigated. Addition of 0.05 g L−1 Fe0 and 0.1 M H2O2 yields 85.2% total organic carbon removal of NMP (10 mM) in 6 h at pH 4.0 ± 0.2. To explore the changes of the nitrogen species, released NO2−, NO3−, and NH4+ are also monitored during the reaction. The present study provides an effective method for the mineralization of NMP‐containing wastewater.