Study on the Mechanism and Control Strategy of Advanced Treatment of Yeast Wastewater by Ozone Catalytic Oxidation

Abstract

In this paper, the yeast wastewater secondary treatment effluent using catalytic odor oxidation treatment, using an orthogonal reaction experiment to determine the best reaction conditions, and the online monitoring of the pH, oxidation-reduction potential (ORP), and liquid ozone concentration monitoring, to the catalytic odor oxidation reaction, chemical oxygen demand (COD), and color removal effect were analyzed. The results showed that the optimal reaction condition for the advanced treatment of yeast wastewater by catalytic ozonation was accomplished with manganese dioxide used as the catalyst and a catalyst dose of 6 g·L−1, pH of 12, and catalytic ozonation reaction time of 20 min. The COD was effectively reduced from 880 mg·L−1 to 387 mg·L−1 under this condition, the chroma was reduced from 700 times to 40 times, and these two parameters of the effluent could meet the standard of GB25462-2010. The real-time monitoring system showed that the whole reaction can be divided into two processes. The first 14 min was the indirect reaction of ozone and then the direct oxidation reaction of ozone. This process was further verified by the change trend of COD and the amount of ozone depletion by COD removal. The average ozone consumption levels of the two stages were 1.97 and 4.91 mgO3·mgCOD−1. This system can effectively monitor the reaction of the catalytic odor oxidation in the complex system to guide the effective use of ozone in practical engineering applications.