Electromagnetic Fenton Combined with Electro-Biological Coupling Technology for Treating High-Nitrogen Organic Chemical Wastewater.

Abstract

High-nitrogen organic chemical wastewater is characterized by high chemical oxygen demand (COD Cr ), poor biodegradability, and toxic nitrogenous organics, posing significant challenges for conventional biological treatment. In this study, a dual-electrical treatment strategy integrating an electromagnetic Fenton (EM-Fenton) pretreatment unit with a three-dimensional biofilm electrode reactor (3D-BER) is proposed. The EM-Fenton system used iron-carbon fillers under electric and magnetic fields to generate hydroxyl radicals (·OH), enabling efficient oxidation of nitro-aromatic compounds and the conversion of organic nitrogen into NO 3 - -N, while reducing Fe 2+ input and iron sludge generation. Subsequently, the 3D-BER, filled with Fe 3 O 4 /Mn 3 O 4 -modified polyurethane spheres, facilitated autotrophic denitrification and phosphorus removal through enhanced extracellular electron transfer and trace hydrogen (H 2 ) release. Experimental results demonstrated that the EM-Fenton system achieved COD Cr and NH 4 + removal rates of over 40% and 14%, respectively, under optimal HRT. The 3D-BER further improved removal efficiencies, with TN and TP reductions exceeding 80% and 81%, respectively, significantly outperforming the control groups. Microbial analysis revealed the enrichment of functional genera, such as Pararhodobacter and Thauera , and the upregulation of key denitrification pathways. This coupled system demonstrated high treatment efficiency, process synergy, and microbial selectivity, offering a promising approach for the advanced treatment of high-nitrogen industrial wastewater.

Keywords

Identifiers

DOI

10.3390/toxics13121059

PubMed

41441280

Journal

Toxics

Year

2025