Thermal Degradation of Chloroteracycline in Animal Manure and Soil

Veterinary antibiotics used in livestock and poultry production may be present in manure and slurry as the parent compound and/or metabolites. The environment may therefore be exposed to these antibiotics due to the application of animal manure to agricultural land. In order to reduce the amount of veterinary antibiotics ultimately released into the environments, it is necessary to treat properly animal manure before its application in agricultural land. In this paper, the effect of temperature on degradation of chlortetracycline (CTC) in animal manure and soil was investigated under laboratory conditions. Degradation of the CTC in both animal manure and soil under different temperature conditions followed first-order kinetics. Increasing temperature greatly accelerated CTC degradation, and thermal degradation became significant at high temperature (>30 degrees C). The degradation rate of the CTC was faster in animal manure than manure-amended soil and soil, suggesting that CTC may become persistent in the environment once it was released from manure into soil.