Electrodes bioaugmentation promotes the removal of antibiotics from concentrated sludge in microbial electrolysis cells.

Microbial electrolysis cells (MECs) had a potential to improve antibiotics removal from wastewater. However, research on antibiotics removal from concentrated sludge using MECs is still very limited. In this study, antibiotics removal and microbial responses in MECs treating concentrated sludge under different applied voltages (0.3 V–1.5 V) were investigated. Results showed that antibiotics removal efficiencies at 0.6 V and 1.0 V were 16.7%–26.6% higher than other applied voltages. The applied voltages had no obvious effects on the viability, activity and composition of microorganisms in the suspended sludge even up to 1.5 V. Bioelectrodes exhibited higher bioelectrocatalytic activity and denser microbial aggregation at 0.6 V and 1.0 V, under which higher antibiotics removal was also achieved. The enhanced removal of antibiotics at the optimal applied voltages was mainly contributed by the bioaugmentation of electrodes, but was irrelative with the electrochemical reaction and the microbial responses in suspended sludge. Unlabelled Image • Antibiotics removal in MECs at room temperature was comparable to mesophilic AD. • Antibiotics removal from concentrated sludge was enhanced at 0.6 V and 1.0 V. • Enhanced antibiotics removal in MECs was irrelative with the suspended sludge. • Bioaugmentation of electrodes contributed to the enhanced antibiotics removal. [ABSTRACT FROM AUTHOR]