Synergistic enhancement of phenol degradation in coal chemical wastewater via micro-nano bubble-domesticated microbial consortia

Coal chemical wastewater, characterized by high toxicity, salinity, and refractory organics (e.g. phenols), poses significant environmental challenges. An innovative system integrating micro-nano bubbles (MNBs) and acclimated bacterial consortia (DP-1) was developed in this study. It was designed to achieve efficient phenol degradation and chemical oxygen demand (COD) removal. DP-1 was domesticated under MNBs aeration, high phenol (up to 400 mg/L), and high-salt (1-15 g/L) conditions, exhibiting remarkable adaptability. The MNBs@DP-1 system achieved 100% phenol degradation and 88.9% COD removal within 24 h at 600 mg/L phenol, demonstrating robust performance across a wide pH range (6-9) and salinity (1-15 g/L). Notably, in a sequencing batch biofilm reactor (MNB-AR), long-term treatment of actual coal chemical wastewater (COD: 1300-1600 mg/L) yielded a stable average COD removal of 76.2% with <1.6% fluctuation. Microbial community analysis revealed <i>Proteobacteria</i> (99.1%) dominance post-acclimation, with <i>Acinetobacter</i> (65.7%) and <i>Comamonas</i> (29.7%) as key functional genera driving phenol mineralization. Comparative studies confirmed the superior efficacy of MNBs@DP-1 over conventional aeration systems, attributing enhanced degradation to MNBs-induced bacterial activity and biofilm stability. This work provides a scalable strategy for achieving 'zero discharge' in coal chemical wastewater treatment by synergizing bubble technology and microbial acclimation.