农村污水间歇断流下滴滤池效能维持及微生物胞外应激机制

The adaptive resilience of microorganisms is crucial for maintaining the stable operation of Biotrickling filters under intermittent flow interruption. This process is intrinsically related to the ability of microorganism to store active substances as Extracellular Polymeric Substances (EPS). To elucidate this mechanism, a comparative analysis was conducted on biofilm structural characteristics, EPS compositional variations, and functional group transformations during an operation cycle of Biotrickling filters. The correlation between EPS-mediated stress response mechanisms and microbial activity maintenance/recovery was investigated. The results revealed that the removal of COD and NH₄⁺-N reached (95.56±1.10)% and (87.06±2.08)% respectively in the biotrickling filter operated under intermittent flow. Under the regulation of EPS, the biofilm showed a loose and porous structure. During flow interruption phases, microorganisms activated starvation adaptation strategies by converting carbon sources adsorbed in SB-EPS and metabolizing polysaccharides stored in SB-EPS. The structure integrity of microorganisms was maintained via synergistic effects of hydrophobic functional groups within EPS and polymer bridging interactions. Accordingly, an EPS-mediated stress adaptation system responsive to starvation-recovery alternations was established, enabling sustainable operation of Biotrickling filters.