Removal of antibiotic resistance genes in the breeding wastewater by the ferrate treatment at different sulfite concentrations

The investigation focused on the removal of antibiotic resistance genes from wastewater using ferrate treatment at various sulfite concentrations. As the sulfite concentration increased from 0 to 28.5 mg/L, the total DNA removal rate treated by 10 mg/L ferrate increased from 71.45% to 96.48%. The antibiotic resistance genes, save our souls genes and class I integron abundance reduction treated by ferrate ranged from 0.02 log to 1.66 log copies/ml at different sulfite concentrations, and the antibiotic resistance gene parC removal was enhanced as the sulfite addition. When the sulfite concentration reached to 28.5 mg/L, the catalase and superoxide dismutase levels were decreased by 21.57% and 10.04%, respectively, while the reactive oxygen species and lactate dehydrogenase levels were increased by 75.34% and 28.67%, respectively, compared to those in the wastewater treated by alone ferrate without sulfite. In the coupled ferrate (10 mg/L) and sulfite (28.5 mg/L) system, sulfate radicals and hydroxyl radicals were the main contributors to the DNA removals, and their contribution rates were 51.99% and 28.95%, respectively. The antibiotic resistance genes and save our souls genes hosts changes showed microbial community significantly affected the DNA removal. This study offers novel comprehensions on the antibiotic resistance genes removal from the wastewater by the combined ferrate and sulfite.