influence of cefixime trihydrate on the biological properties of activated sludge

activated sludge is an aerobic biological wastewater treatment process. this process has been efficiently and extensively used for the treatment of industrial and municipal wastewaters since about 100 years ago. some drugs such as antibiotics have adverse effects on the bacteria in activated sludge. cefixime trihydrate is a semi-synthetic antibiotic belonging to the third generation of cephalosporins. in this research the effect of cefixime on the biological operational parameters of activated sludge process was investigated. mlss, svi, cod and microscopic analysis of sludge texture were evaluated. the results showed that by carefully controlling of the operational parameters in adopting period, sludge quality can be kept in acceptable level. mlss of 3500 ppm, ph of 6.7 and svi of 90 ml.g-1 were average controlled parameters. the cod reduced from 800 to 40 ppm after implementing the adoption period. optical microscopic analysis showed that after adoption period, microorganisms such as protozoa and ciliate are active in activated sludge even in the presence of antibiotic.