THE EFFECT OF ANTIBIOTICS ON NITRIFICATION PROCESSES - BATCH ASSAYS

The effect of different antibiotics at several concentrations of ampic illin (0-250 mg/L), benzylpenicillin (0-250 mg/l),novobiocine (0-150 m g/L), oxytetracycline (0-250 mg/L), and chloramphenicol (0-50 mg/L) on a stabilized nitrifying sludge was evaluated under aerated and lithoa utotrophic conditions. No effect resulting from the presence of antibi otics on the biomass and nitrate production was noticed. The specific growth rate and volumetric nitrification rate average values for the c ontrols were 8.28 x 10(-3)/h(-1) and 2.74 x 10(-3) g/L . h, respective ly. Similar rate values were found when different kinds of antibiotic and concentrations were tested. These results may be explained by the nature of the flee or the instability of the antibiotics.