Attenuation of tetracyclines during chicken manure and bagasse co-composting: Degradation, kinetics, and artificial neural network modeling

The main objective of this study was to investigate the feasibility of using a locally abundant bulking material (bagasse) in the composting process to remove tetracycline from chicken manure in Khuzestan Province, Iran. Degradation extent and kinetic of three types of tetracycline (tetracycline hydrochloride (TCH), chlortetracycline (CTC), and oxytetracycline (OTC)) during co-composting of chicken manure and bagasse were investigated. After 56 days of incubation in the dark and room temperature, TCH, CTC, and OTC were removed up to 99.0%, 99.3%, and 99.5%, respectively. Highest Tetracyclines (TCs) removals were observed when chicken manure was composted with 14% bagasse. Both simple and availability-adjusted first-order kinetic models fitted TCH, CTC, and OTC degradation data. Half-lives estimated by both models were close together. TCH, CTC and OTC half-lives were estimated to be 8, 5, and 4 days, respectively. An artificial neural network model was developed to model TCs degradation. Artificial neural network analysis showed the relative importance of time, antibiotic type, bagasse percentage, and initial antibiotics concentration, in TCs degradation to be 80.43%, 7.95%, 6.43%, and 5.17%, respectively.