Effects of Chlortetracycline Hydrochloride and its UV Degradation Products on Growth of Freshwater Algae

[Objective] The aimwas to study the ecological risk when tetracyclines antibiotics entered the waterenvironment and anotheren-vironmental factorwhich influenced the growth of algae.[Method] Effects of chlortetracycline hydrochloride and UV light degradation of chlortetracycline hydrochloride on alga growth and chlorophyll a content were investigated by Microcystis aeruginosa and Scenedesmus obliquus.[Result] MS Chlortetracycline hydrochloride inhibited the growth of the two algae except that 0.5 mg/L of chlortetracycline hydrochloride promoted the growth of Microcystis aeruginosa.With the increase of concentration of chlortetracycline hydrochloride,the inhibition strengthened but 10 mg/L of chlortetracycline hydrochloride couldn’t inhibit the growth of the two algae completely.Chlortetracycline hydrochloride degradedby UV light had different effects on growth of the two algae.The biomass and chlorophyll a content of Microcystis aeruginosawere as follows:chlortetracycline hydrochloride degraded by UV light for2 h1 h4 h0 h8 h12 h24 h.To Scenedesmus obliquus,the control grouphad the biggest biomass and chlorophyll a content which decreased with the increasing degraded time in experimental groups.[Conclusion]Effects of chlortetracycline hydrochloride on freshwater algae were ralated to its concentration and algal species.Effects of UV degradation of chlortetracycline hydrochloride on freshwater algae were ralated to its degradation time and algal species.