Synergistic optimization of bioretention cells for antibiotic removal and denitrification by iron-copper bimetallic catalytic system with Phalaris arundinacea

Abstract

Bioretention cells have been less studied for treating stormwater runoff and removing antibiotics and denitrification. In this experiment, bioretention cells with iron-copper bimetallic catalysis and Phalaris arundinacea were constructed and synergistically optimized. The performance of antibiotic removal and denitrification under single and compound antibiotic stress was investigated, and the microecological environment of the system was analyzed. The results showed that under single and compound antibiotic stress, the removal rates of ofloxacin (OFLX) and tetracycline (TC) reached 91.69 %–99.57 % and 95.96 %–99.74 %, respectively. The TN and NH₄⁺-N removal rates were 68.74 %–74.90 % and over 71.15 %, respectively. Rhodanobacter, Zoogloea and Holophaga played important roles in antibiotic degradation and denitrification. Denitrification functional genes nirS, norB, nosZ and narG showed a trend of decreasing relative abundance under the influence of antibiotics. These results suggested that bioretention cells can remove antibiotics and nitrogen by affecting microbial and denitrification gene changes. These findings provided a reference for performance optimization and practical application of bioretention cells in the field of antibiotic removal and nitrogen removal.