Target Fishing and Molecular Docking for Phenanthrene–pyrene Co-degradation of the Niche Effect of Polycyclic Aromatic Hydrocarbons in Reclaimed Water

PAHs pollution is a widespread pollution in river basins and wetland water bodies. A Northeast China chemical industry zone was studied, focusing on reclaimed water and sludge from sewage treatment plants. The pollution levels of 16 polycyclic aromatic hydrocarbons (PAHs) were monitored across three water periods. A model comparing pollution levels with sludge and recycled water aroma indices was established and validated. The model revealed interaction relationships among the 16 PAH pollutants. Analysis of bacterial communities identified the mechanism for combined phenanthrene and pyrene degradation, along with nine key enzymes involved. Population responses to 16 PAH pollution stress were explored, highlighting metabolic differences and functional relationships within eukaryotic and prokaryotic microbial communities. Molecular dynamics simulations identified a key enzyme, uncovering pi–pi T-shaped and pi–alkyl forces in the interaction between pyrene dioxygenase and pyrene.