Treatment of Antibiotics Wastewater Utilizing Successive Hydrolysis, Denitrification and Nitrification

A process consisting of anaerobic hydrolysis, denitrification, and oxidation/nitrification was proposed for simultaneous removal of carbon and nitrogen from terramycin crystallizing mother solution (TCMS), and its performance was investigated by treating diluted TCMS in a lab-scale continuous flow column system. Direct denitrification-nitrification of diluted TCMS produced a significant residual of nitrate and nitrite, which disappeared 44 days after startup of anaerobic hydrolysis column. The electron donors available to denitrification were increased by 6 times after diluted TCMS was treated in the hydrolysis column under an HRT of 2.5 h or longer. The reaction rates of organics decomposition, nitrification, and denitrification were also significantly increased due to reduction of terramycin and decomposition of complicated molecules to small molecules during anaerobic hydrolysis. The specific denitrification rate and nitrification rate increased from 0.033 d(-1) and 0.01 d(-1) to 0.045 d(-1) and 0.021 d(-1) respectively after diluted TCMS (dilution ratio: 1:4) was hydrolyzed in anaerobic hydrolysis column at a hydraulic retention time (HRT) of 4 h.