Enhanced printing and dyeing wastewater treatment using anaerobic-aerobic systems with bioaugmentation

Printing and dyeing wastewater (PDW) is characterized by various pollutants, making it one of the most difficult industrial wastewaters to treat and poses a serious threat to the natural environment and public health. This study investigated the use of an anaerobic-aerobic system combined with bioaugmentation using Ochrobactrum anthropi S1 to treat PDW. The results indicated that after three rounds of inoculation, Ochrobactrum anthropi S1 successfully colonized the system, achieving final removal efficiencies of reactive black 5, Cr(Ⅵ), COD, and ammonia nitrogen of 95 %, 65 %, 90 %, and 85 %, respectively. Microbial community analysis further revealed differences in community dynamics between the anaerobic and aerobic phases. During the anaerobic phase, microbial community assembly was primarily shaped by stochastic processes (60 %), whereas the aerobic phase was governed by deterministic processes (65 %). Additionally, co-occurrence network analysis suggested that microorganisms in the aerobic phase may form more complex interactions compared to the anaerobic phase, thereby enhancing pollutant removal efficiency. This study confirms that bioaugmentation with Ochrobactrum anthropi S1, combined with anaerobic-aerobic technology, is an effective strategy for treating PDW, enhancing both system stability and microbial performance.