Effect of instantaneous soybean wastewater impact on sequencing batch reactor and emergency control strategy

Based on the practical problem that excessive effluent pollutants caused by the impact of soybean wastewater on urban sewage treatment system, the effect of soybean wastewater on pollutants removal in sequencing batch reactor (SBR) and emergency control measures were investigated through single cycle instantaneous wastewater impact test. The results showed that with the increase of water quality impact load, COD removal rate increased initially and then decreased, while NH4+-N and TN removal rates increased gradually. The effect of water quality impact on TP removal was relatively small. When COD of the impact wastewater was 370 mg/L, the effluent NH4+-N and TN could not meet the first level class A standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002). As the water volume impact increased, the changes of COD and TN removal rates remained consistent with the water quality impact, and the effect of water volume impact on NH4+-N and TP removal was relatively small. As the impact of water quality and water volume increased, the protein(PN) and polysaccharide(PS) components in extracellular polymeric substances(EPS) were both affected. Regulating the aeration rate could be used as an effective emergency control measure for the impact of soybean products wastewater. When the COD of the impact wastewater was 370 mg/L and the aeration rate was 0.9 L/min, COD, NH4+-N, TN, and TP could all meet the discharge standards. The results could provide reference for coping with the impact of other loaded soybean products wastewater.