Copper inhibition of enhanced biological phosphorus removal (EBPR) was examined in batch experiments under anaerobic and aerobic conditions. Inhibition was represented by both acetate uptake and phosphorus release coefficients under anaerobic conditions, and by a phosphorus uptake coefficient under aerobic conditions. The results showed that copper inhibition of EBPR occurred mainly during aerobic phosphorus uptake and a first-order phosphorus uptake coefficient can be better used to describe the inhibition effect. For the aerobic phosphorus uptake using the EBPR activated sludge, (i) copper inhibition started at 0.07 mg/l, (ii) 50% and 100% inhibition occurred at 0.30 mg/l and 0.53 mg/l, respectively, and (iii) the inhibition constant was 0.48 mg/l.
Keywords: copper, enhanced biological phosphorus removal, heavy metals, inhibition