Antibiotics elimination in livestock manure during composting

In this study, cow manure, chicken manure, and swine manure were selected to investigate the effect of initial moisture content and frequency of composting on antibiotic reduction in aerobic composting, and optimized conditions for aerobic composting by using API 5000triple quadrupole mass spectrometer (minimum detection limit 0.5~1.0µg/L). The results showed that sulfonamides, fluoroquinolones and tetracyclines were the main types of antibiotics in manure, with the concentration ranging from 1.37~72.43, 26.26~37.1 and 24.48~34.81µg/kg, respectively. Antibiotic residues in manure gradually decreased with composting time. Under a certain initial moisture content (55.87%~68.11%) and turning frequency (no turning or twice a day), the total antibiotic removal rate in the manure reached 78.09%~92.01% after 32 days of composting. Changes in the initial moisture content and turning frequency could significantly affect the rate of antibiotic reduction in livestock manure. The antibiotic removal rate could be up to 100% when the compost had an initial water content of 68.11% and the compost was turned frequently. Therefore, the rational optimization of composting treatment techniques could be advantageous for the effective elimination of antibiotics from manure as well as for achieving resource efficient and harmless treatment of manure. © 2024 Chinese Society for Environmental Sciences. All rights reserved.