摘要
The increasing application of engineered nanoparticles(NPs) has posed an emerging challenge to constructed wetland wastewater treatment. The performance, microbial community and toxic mechanism of anammox-based unplanted subsurface-flow constructed wetlands(USFCWs) were investigated under the long-term exposure of different graphene oxides(GOs) and Ag NP concentrations. Results showed that the addition of GO could promote TN removal, manifesting as function anammox bacteria C. Anammoxoglobus having a relative high abundance, for GO did not cause significant damage to the cell integrity though there was an increase in ROS concentrations. TN removal would not be obviously affected under exposure of 1 mg/L Ag NPs, for the function gene related to cell biogenesis and repair was up-regulated; while the addition of 10 mg/L Ag NPs would have an inhibiting effect on TN removal in the USFCWs, for the disappearance of some species having anammox ability. Key enzymes of anammox process(NIR and HDH) decreased to some extent under GO and Ag NP exposure, and function gene of defense mechanisms had an increase trend in samples.
The increasing application of engineered nanoparticles(NPs) has posed an emerging challenge to constructed wetland wastewater treatment. The performance, microbial community and toxic mechanism of anammox-based unplanted subsurface-flow constructed wetlands(USFCWs) were investigated under the long-term exposure of different graphene oxides(GOs) and Ag NP concentrations. Results showed that the addition of GO could promote TN removal, manifesting as function anammox bacteria C. Anammoxoglobus having a relative high abundance, for GO did not cause significant damage to the cell integrity though there was an increase in ROS concentrations. TN removal would not be obviously affected under exposure of 1 mg/L Ag NPs, for the function gene related to cell biogenesis and repair was up-regulated; while the addition of 10 mg/L Ag NPs would have an inhibiting effect on TN removal in the USFCWs, for the disappearance of some species having anammox ability. Key enzymes of anammox process(NIR and HDH) decreased to some extent under GO and Ag NP exposure, and function gene of defense mechanisms had an increase trend in samples.
基金
financially supported by the National Key R&D Program of China(No.2017YFC0505901)
the National Natural Science Foundation of China(Nos.41401548
41772244)
the Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.HC201622)
the China Scholarship Council(Nos.201804910339,201806175055)
