Salt-Resistant Catalyst Fe-Bi@γ-Al₂O₃ for Catalytic Ozonation of High-Salt Simulated Wastewater

In order to study the effects of common ionic components in wastewater on the catalytic performance and salt resistance of the Fe-Bi@γ-Al₂O₃ catalyst, hydroquinone was selected as the target organic pollutant. Five factors, namely cation species, anion species, total hardness, total alkalinity, and TDS were studied to investigate the effects of different ionic components on the degradation of hydroquinone by the Fe-Bi@γ-Al₂O₃ catalyst. K⁺ and Na⁺ had basically no effect on the COD removal rate, and the COD removal rates were 81.43% and 83.81%, respectively, with no significant change from the COD removal rate from raw water (85.24%), Cu²⁺ and Al³⁺ had some inhibitory effect on the COD removal rate, and the COD removal rate was 68.57% and 70.00%, respectively. While, the presence of Fe³⁺, Cl⁻, Br⁻ and SiO₃²⁻ had a significant inhibitory effect on the COD removal rate, and the COD removal rate was 61.90%, 51.90%, 55.71% and 60.48%. The concentration of Ca²⁺ was 50 mg/L and Mg²⁺ was 200 mg/L, the COD removal rate was 57.62% and 60.48%, respectively due to water hardness. The alkalinity had an inhibitory effect on the treatment effect of simulated waste water, when the OH concentration was 1500 mg/L, the COD removal rate was 49.05%. The higher the TDS concentration, the more obvious was the inhibitory effect on the COD removal rate, and the COD removal rate was 41.43% when the TDS was 50,000 mg/L. The intermediates and possible degradation mechanisms after catalytic ozone oxidation of hydroquinone-simulated wastewater by Fe-Bi@γ-Al₂O₃ were investigated by UV spectroscopy scanning, 3D fluorescence spectroscopy scanning, and GC–MS scanning.