Bioaugmented Treatment of Erythromycin by Engineered Microorganism in Surface Water
Erythromycin-degrading strains were isolated from activated sludge collected from a sewage treatment plant,which were identified as Pseudomonas putida. It was found that the removal rate as high as 76.6% of erythromycin within 5d could be achieved at temperature of 30 ℃,pH of 7.0 ~7.5,initial erythromycin concentration of 30 mg/L. Removal of erythromycin was investigated as isolated degrading-strains were inoculated into biological aeration filters(BAF),using bioceramic media and volcanic rock as the filters. Results showed that the effect with erythromycin-degrading bacteria addition on start-up of BAF was negligible. However,the erythromycin removal increased at the beginning and then decreased as the aeration intensity increased. The erythromycin removal decreased when the hydraulic residence time decreased. The performance during the stable operation indicated that the erythromycin removal efficiencies by bioaugmented bio-ceramic media and bioaugmented volcanic rock filters increased by 33.9% and 40.1% respectively, demonstrating that the improvement of erythromycin removal via bioaugmentation was feasible and effective.