Fe-C Micro-Electrolysis of HMX: Performance Optimization, Degradation Mechanisms, and Toxicity Evolution Revealed by...

This study evaluated the degradation of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) in simulated wastewater using an iron-carbon (Fe-C) micro-electrolysis system. The treatment efficiency was systematically evaluated under varying initial pH, Fe dosage, and Fe/C mass ratios. Under the optimized operating conditions (initial pH of 4, Fe dosage of 70 g/L, and an Fe/C mass rat of 1:1), the system achieved a maximum HMX removal efficiency of 98.4%. Kinetic analysis indicated that the degradation process conformed to pseudo-first-order kinetics. Mechanistically, HMX removal was attributed to interfacial adsorption and co-precipitation via in situ generated Fe²⁺ and Fe³⁺ hydroxides, alongside reductive transformation mediated by Fe, Fe²⁺, and nascent hydrogen ([H]) evolved during the micro-electrolysis process. To assess the molecular toxicity evolution of the treated wastewater, a toxicogenomic assay was deployed to evaluate the molecular toxicity evolution of the treated wastewater matrix. The transcriptomic profiling revealed that DNA damage and oxidative stress were the predominant cellular stress responses induced by the wastewater. While the total toxic effect transcript index (TELI_total) exhibited a transient initial increase before steadily declining, the overall toxic potency remained within a relatively stable range throughout the treatment cycle. Ultimately, this study provides critical insights into process optimization and pathway elucidation, demonstrating that Fe-C micro-electrolysis is a promising and scalable pretreatment technology for the remediation of energetic compound-laden industrial effluents.