Advanced treatment of wastewater from sauce-flavor Baijiu production with reusing distillers' grains by Cu/AC ozone catalytic oxidation

The advanced treatment effect of the micro-bubble ozone catalytic oxidation process with copper oxide loaded on activated carbon (Cu/AC) as catalyst on biochemical effluent from sauce-flavor (Jiangxiangxing) Baijiu production with reusing distillers' grains wastewater was studied. The results showed that the catalyst addition in sequence batch reactors was 15 g/L, the ozone addition was 12.5 mg/min, and initial pH was 7.5, the removal efficiencies of chemical oxygen demand (COD) and ultra violet absorption value at wavelength 254 nm (UV₂₅₄) were 79.0% and 94.7%, respectively. After multiple cycles of catalyst usage, the decreases in COD and UV₂₅₄ removal efficiencies were less than 5%. Characterization revealed a smooth morphology of the catalyst surface, with copper predominantly existing as CuO and dispersed on AC, enhancing catalytic performance. The removal efficiencies of COD and UV₂₅₄ remained at 76% and 92% after long-term continuous operation, indicating strong stability and shock resistance. The results provided a reference for the application of the micro-bubble ozone catalytic oxidation system in treating wastewater from sauce-flavor Baijiu production with reusing distillers' grains.