Treatment performance of multistage active biological process (MSABP) reactor for saline sauerkraut wastewater: acclimatization, optimization and improvement.

The wastewater with a high concentration of organics and salt is a major contaminant in the production of sauerkraut. In this study, a multistage active biological process (MSABP) system was constructed to treat sauerkraut wastewater. The key process parameters of the MSABP system were analyzed and optimized by response surface methodology. The optimization results indicated that the most optimal removal efficiencies and removal loading rates of chemical oxygen demand (COD) and NH-N were 87.9%, 95.5%, 2.11 kg·m·d and 0.12 kg·m·d, respectively, with hydraulic retention time (HRT) of 2.5 d and pH of 7.3. Meanwhile, this system could also be improved for the further treatment of COD and total nitrogen by effluent recycle and ozone oxidation. The COD and total nitrogen removal efficiencies of the modified MSABP system were 99.9% and 60.2%, respectively. In addition, the modified system could also reduce the potential harm from high concentrations of NO-N.