Coupling effect of high-temperature and microbial community on the removal of antibiotics and antibiotic resistance genes in sludge hyper-temperature aerobic bio-drying system

Abstract

Antibiotic residues and antibiotic resistance genes (ARGs) in sludge pose high risks to human health and the ecological environment. Hyper-temperature aerobic bio-drying system (HTAB) has the potential for higher degradation efficiency of antibiotics and ARGs due to high-temperature and rapid organic matter degradation. This study firstly reports two sludge HTAB processes, hyperthermophilic aerobic bio-drying (HAB) and electro-assisted heating bio-drying (EHAB), for the removal efficiency of four types of antibiotics, quinolones, tetracyclines, macrolides, and sulfonamide antibiotics, and ARGs, as well as the relationship between antibiotics and ARGs. The microbial communities of the two HTAB processes showed significant differences compared to the conventional bio-drying process (CAB). Compared to the CAB, the HTAB significantly improved the removal efficiency of antibiotics and ARGs and shortened the half-life of antibiotics. In the two HTAB processes, the total antibiotic removal of the HAB and EHAB processes was 78.11 and 74.15%, respectively. Compared with the EHAB process, the HAB process had higher removal for all four types of antibiotics, especially significantly improving the removal efficiency of tetracyclines. Compared to the CAB, both HTAB processes significantly enhanced the removal efficiency of ARGs and mobile genetic elements (MGEs). In the two HTAB processes, the HAB showed a higher removal efficiency of ARGs and MGEs compared to the EHAB. The relevant mechanisms indicated that temperature and changes in microbial communities jointly affected the removal efficiency of antibiotics and ARGs.

Keywords:

• sludge bio-drying
• Sludge pollutants
• Antibiotics
• Antibiotic resistance genes
• Bacterial community

Acknowledgments

This work was supported by the National Key Research and Development Program of China (No. 2020YFC1806402) and the Shenyang Science and Technology Plan Project (No. 20-202-4-37).

Disclosure statement

The authors declare there is no Complete of Interest at this study.

Additional information

Funding

This work was supported by the National Key Research and Development Program of China (No. 2020YFC1806402) and the Shenyang Science and Technology Plan Project (No. 20-202-4-37).