Degradation of Antibiotics in Livestock Manure During Composting

Antibiotics are administered to animals for prophylactic and therapeutic as well as growth-promoting purposes, which results in significant concentrations of antibiotics in manure, jeopardizing its land application. Considering the environmental implications, these antibiotics should be removed from the manure. Composting is a low-cost potential technology to stabilize the manure and reduce the concentrations of antibiotics. This chapter reviews the antibiotic concentrations in various types of manure and the influence of antibiotics on composting microbes, and assesses the efficiency of composting to degrade the antibiotics in the manure matrix. The differences in chemical properties determine the degradation of particular antibiotics, whereas the main mechanism is the temperature achieved through the thermophilic phase. However, the distinction is not clear between the biotic and the abiotic factors in this crucial phase. In addition, the role and transformation of metabolites of antibiotics are inadequately addressed in the literature. Thus, the composting process may need to be modified to develop viable methodologies for different antibiotics.