Advanced nitrogen removal from landfill leachate without addition of external carbon using a novel system coupling ASBR and modified SBR

► A novel system coupling ASBR and SBR was proposed to treat real landfill leachate. ► ASBR was used to remove COD and adjust the C/N ratio of leachate for SBR. ► SBR was operated under new mode for advanced nitrogen removal. ► The removal efficiencies of COD and TN were above 90% and 95%, respectively. ► Low sludge production was realized under long-term endogenous metabolism.