Distribution And Fate Of Erythromycin-Phenanthrene In Simulated Aquatic Microcosms

In recent years, antibiotics have received great attention for their increasing usage and detection in the environment. Besides antibiotics, other pollutants also coexist in the environment, such as polycyclic aromatic hydrocarbons. Antibiotics might have influence on the migration, transformation and ecological efficiency of polycyclic aromatic hydrocarbons, as antibiotics show measurable effects in both organisms at low concentrations. In this research, in order to understand the distribution and fate of antibiotics in aquatic ecosystem and accurately assess the ecological risk of antibiotics in environment, erythromycin was chosen to represent antibiotics, and phenanthrene was chosen to represent polycyclic aromatic hydrocarbons. The distribution of erythromycin in aquatic ecosystem and the effects of erythromycin on the distribution of phenanthrene in aquatic ecosystem were investigated by aquatic microcosms and were evaluated by fugacity models. The main research results are as follows:1. When erythromycin was discharged into aquatic environment, it dispersed rapidly from water to other phases in the aquatic environment. Erythromycin was mainly dispersed to the sediments. Meanwhile, erythromycin could be accumulated and metabolized by organisms in ecosystem. Elodea densa presented higher accumulation ability than Brachydanio rerio. The BCF values of erythromycin in organisms in low erythromycin microcosm were higher than that in high erythromycin concentration microcosm, the influence of erythromycin on organisms at low concentration should be paid more attention to when assessing the risk of erythromycin to ecological security.2. When phenanthrene was discharged into aquatic environment, it dispersed rapidly from water to other phases in the aquatic environment. The half-life time for phenanthrene in water was 23 days, the reduce rate for phenanthrene in water was higher than erythromycin. The sediment-water partition coefficient and BCF values for phenanthrene were much higher than erythromycin.3. Erythromycin could change the migration of phenanthrene from water to the organisms in the microcosm. It could increase the concentration of phenanthrene in Brachydanio rerio, which increase the environmental risk of phenanthrene for organisms in aquatic ecosystem. Thus, the influence of antibiotics for their coexisting pollutants should be considered when assessing the ecological risk of antibiotics in environment.