The EBPR system could bear a Cu (II) concentration of 2.5 mg/L in the long run.
EBPR performances were affected by 2.5 mg/L Cu (II) in the adaptation period.
P, COD and NH4+-N removal maintained efficient with 2.5 mg/L Cu (II) after stable.
PAOs had a higher ratio than that of GAOs under the effect of 2.5 mg/L Cu (II).