Silver nanoparticles(AgNPs)have been widely used in many fields,which raised concerns about potential threats to biological sewage treatment systems.In this study,the phosphorus removal performance,enzymatic activity ...Silver nanoparticles(AgNPs)have been widely used in many fields,which raised concerns about potential threats to biological sewage treatment systems.In this study,the phosphorus removal performance,enzymatic activity and microbial population dynamics in constructed wetlands(CWs)were evaluated under a long-term exposure to Ag NPs(0,50,and 200μg/L)for 450 days.Results have shown that Ag NPs inhibited the phosphorus removal efficiency in a short-term exposure,whereas caused no obviously negative effects from a long-term perspective.Moreover,in the coexisting CW system of Ag NPs and phosphorus,competition exhibited in the initial exposure phase,however,cooperation between them was observed in later phase.Enzymatic activity of acid-phosphatase at the moderate temperature(10–20℃)was visibly higher than that at the high temperature(20–30℃)and CWs with Ag NPs addition had no appreciable differences compared with the control.High-throughput sequencing results indicated that the microbial richness,diversity and composition of CWs were distinctly affected with the extension of exposure time at different Ag NPs levels.However,the phosphorus removal performance of CWs did not decline with the decrease of polyphosphate accumulating organisms(PAOs),which also confirmed that adsorption precipitation was the main way of phosphorus removal in CWs.The study suggested that Ag NPs and phosphorus could be removed synergistically in the coexistence system.This work has some reference for evaluating the influences of Ag NPs on the phosphorus removal and the interrelation between them in CWs.展开更多
基金supported by the National Natural Science Foundation of China:“The ecological effect and fate of typical nanoparticles in constructed wetland”(No.51479034)the Fundamental Research Funds for the Central Universities(No.2242019K40064)the Graduate Innovation Project of Jiangsu Province(No.KYCX18—0125)
文摘Silver nanoparticles(AgNPs)have been widely used in many fields,which raised concerns about potential threats to biological sewage treatment systems.In this study,the phosphorus removal performance,enzymatic activity and microbial population dynamics in constructed wetlands(CWs)were evaluated under a long-term exposure to Ag NPs(0,50,and 200μg/L)for 450 days.Results have shown that Ag NPs inhibited the phosphorus removal efficiency in a short-term exposure,whereas caused no obviously negative effects from a long-term perspective.Moreover,in the coexisting CW system of Ag NPs and phosphorus,competition exhibited in the initial exposure phase,however,cooperation between them was observed in later phase.Enzymatic activity of acid-phosphatase at the moderate temperature(10–20℃)was visibly higher than that at the high temperature(20–30℃)and CWs with Ag NPs addition had no appreciable differences compared with the control.High-throughput sequencing results indicated that the microbial richness,diversity and composition of CWs were distinctly affected with the extension of exposure time at different Ag NPs levels.However,the phosphorus removal performance of CWs did not decline with the decrease of polyphosphate accumulating organisms(PAOs),which also confirmed that adsorption precipitation was the main way of phosphorus removal in CWs.The study suggested that Ag NPs and phosphorus could be removed synergistically in the coexistence system.This work has some reference for evaluating the influences of Ag NPs on the phosphorus removal and the interrelation between them in CWs.
