materials metagenome
nZVI and HA-nZVI (1/40) nanomaterials were uniformly mixed with quartz sand at a mass ratio of 1:9 (w/w), respectively. The mixture was packed into glass columns in three layers using a layered packing method to ensure uniform filling, with a material layer thickness of 9 cm. The influent concentration of imidacloprid (IMI) was 50 mg L-1, the pH was maintained at 7.00, and the influent flow rate was 0.2 mL min-1. The microbial composition was determined after 45 days.