1：Experimental Design and Method Selection:

A dual-chamber system separated by a salt bridge was designed, integrating cathodic electro-Fenton with anodic photocatalysis. The electro-Fenton process was optimized using a Fe@Fe2O3/CF cathode and TiO2 photoanode under UV irradiation.

2：Sample Selection and Data Sources:

Biologically pretreated coal gasification wastewater was obtained from a full-scale treatment facility, with initial COD of 150-200 mg/L.

3：List of Experimental Equipment and Materials:

Equipment includes a dual-chamber reactor, DC power supply, UV lamp, air compressor, pH meter, SEM, XRD, BET analyzer, CV workstation, HPLC, ESR spectrometer. Materials include carbon felt, TiO2, FeCl3·6H2O, NaBH4, Na2SO4, H2SO4, NaOH, TBA, BQ, DMPO.

4：Experimental Procedures and Operational Workflow:

The cathode was prepared by loading Fe@Fe2O3 on carbon felt. Wastewater was treated in the cathodic chamber with optimized parameters (current density 10 mA/cm2, pH 3, air flow

5：4 L/min). Samples were collected periodically for analysis. Data Analysis Methods:

COD, BOD5, TOC, total phenols, H2O2 concentration, iron leaching, and acute toxicity were measured using standard methods. Kinetics were analyzed, and reactive species were identified using scavengers and ESR.