Sauce wastewater treatment process based on synchronous degradation of COD and color

Based on the analysis of the characteristics of sauce wastewater and its treatment difficulties, an efficient treatment process has been successfully designed to solve the problems of color lightening in the anaerobic condition and darkening in the aerobic condition, which result in a synchronous degradation of color and COD. The study on the effect of oxidant, reducer, temperature and metal ions on decoloration indicates that by maintaining pH in a range of 7.0-7.2 and adding a bit of oxidants or appropriate metal ions, especially Ca²⁺, the synchronous degradation of COD and color can be achieved and the repeated color transform can be avoided effectively. The improved sauce wastewater treatment process 'modulation-deposition-hydrolization-II SBR' can decolorize the wastewater independent of floatation, reduce the amount of active sludge produced and shorten the process effectively, so the operating cost is lowered while the treating capacity is improved.