关键词: Coking wastewater, Biochemical treatment, AgNO₃ + K₂FeO₄ catalytic oxidation, Cyclic organics, Degradation characteristics

Abstract: In this work, a coking wastewater was selected and a biochemical A²/O treatment device for fractional degradation was designed and employed. After each stage of the treatment, the products were analyzed through gas chromatography-mass spectroscopy (GC-MS) to determine their composition. Finally, AgNO₃ + K₂FeO₄ was used as an advanced deep catalytic oxidation treatment. It was concluded from the analysis that cyclic organics could be degraded and the chemical oxygen demand (COD) was controlled within 50 mg·L^-1, in line with the target value. Meanwhile, the spectra obtained from the GC-MS were in accordance with the conclusions reached based on the COD. The research results showed that all hard-degradable organics in coking wastewater could be eliminated through the A²/O bio-membrane treatment and the advanced treatment of making use of K₂FeO₄ as an oxidant and Ag⁺ as a catalyst, the catalytic efficiency with Ag⁺ as a catalyst of K₂FeO₄ was very high. Ag⁺ could evidently improve the oxidation capacity of K₂FeO₄ to wastewater in its short stability time, and this is an important innovation.

Key words: Coking wastewater, Biochemical treatment, AgNO₃ + K₂FeO₄ catalytic oxidation, Cyclic organics, Degradation characteristics