A novel environmentally friendly catalyst for the preparation and degradation of DNT in dynamite wastewater: Performance, mechanism and application

Abstract

This study proposes a novel approach to sustainable recycling through the preparation of a JCA₅Fe@CNs catalyst, which demonstrates excellent performance. The catalyst was synthesized by loading nZVI onto biomass carbon-based precursors using a chemical modification-pyrolysis technique, with discarded date palm as the raw material. The new catalysts were prepared for a wide range of pH conditions and neutral conditions were preferred. The catalyst was able to degrade approximately 80 % of 2,4-Dinitrotoluene (2,4-DNT, 20 mg/L) within 5 min, with a maximum degradation rate constant (k) of 1.42162 min⁻¹. Synchrotron radiation and density functional theory (DFT) calculations confirmed that the catalytic performance and stability of nZVI were significantly enhanced when incorporated into date-palm-based biomass carbon carriers. The degradation mechanism of 2,4-DNT was investigated using EPR and quenching experiments, revealing that reactive oxygen species (ROS) generated during the reaction involved both radical and non-radical pathways. HPLC-MS analysis identified several reaction intermediates, and potential degradation pathways for 2,4-DNT were proposed. Finally, a flow wastewater model was constructed to evaluate the catalyst's performance in 2,4-DNT degradation under a flow system, assessing its practical application potential. In conclusion, the JCA₅Fe@CNs catalyst, prepared using the modification-pyrolysis strategy, shows promising potential for the treatment of challenging organic wastewater.