Pyrolysis of antibiotic mycelial dreg and characterization of obtained gas, liquid and biochar.

The disposal and utilization of antibiotic mycelial dreg (AMD), which has been identified as a hazardous waste in China, are a serious concern because of the residual antibiotic and huge annual output. Pyrolysis is a promising technology to treat AMD. However, the pyrolysis of AMD is not studied in an adequate degree, particularly no attention has been paid to the release and distribution of the phosphorus in AMD during pyrolysis. Therefore, the present work studied the pyrolysis of AMD more comprehensively. The influence of pyrolysis temperature on product yields and characteristics, together with the release and distribution of nitrogen and phosphorus, and the antibiotic residue in products, were investigated. The results suggested that residual antibiotic was eliminated after pyrolysis. Nitrogen was mainly contained in the biochar and liquid products, while phosphorus was mainly retained in the biochar. Liquid products were characterized by abundant oxygen and nitrogen-containing compounds, while biochar was featured of both abundant nitrogen and inorganic phosphate groups. Pyrolysis temperature showed a significant effect on product yields and characteristics, and a low pyrolysis temperature is recommended considering the recycling of nitrogen and phosphorus. The disposal of AMD through pyrolysis conforms to the principles of AMD disposal.