Removal Characteristics of Human Antibiotics during Wastewater Treatment in Japan

Pharmaceuticals resident in sewage and in the aqueous environment has begun to attract attention. The objectives of this research were to clarify the behaviour of selected human antibiotics in wastewater treatment plants, namely levofloxacin (LVFX), clarithromycin (CAM) and azithromycin (AZM) which are much used in Japan. The concentrations in raw influent of LVFX, CAM, AZM were respectively 425~981ng/L, 340~573ng/L, ND(<190 ng/L)~371ng/L. The averages of removal ratio were about 50 % for all selected antibiotics. It was suggested that selected antibiotics was not too much removed in the conventional creature processing like the conventional activated sludge process. The remarkable removals in activated sludge tank using high class treatment method were confirmed about all selected antibiotics. The rise of the concentrations of CAM and AZM was confirmed after the addition of chemical coagulants in one wastewater treatment plant. From the result of batch experiment with activated sludge, it was suggested that LVFX and AZM were removed from water mainly by the absorption to activated sludge. Also, in batch experiment with chemical coagulants, it was suggested that LVFX was removed from water and CAM, AZM were eluted a little in water by adding sulphuric acid band.