title: The impacts of silver nanoparticles and silver ions on wastewater biological phosphorous removal and the mechanisms.
abstract: The effects of AgNPs and Ag+ (0-5 mg/L) on wastewater enhanced biological phosphorus removal (EBPR) were investigated. The phosphorus removal efficiency was maintained at 99% no matter what the concentrations of AgNPs were, but it was decreased to 48.8% at Ag+ of 1 mg/L, and no net phosphorus was removed at Ag+ greater than 2 mg/L in the batch tests. The uptake of wastewater carbon source and the anaerobic and aerobic transformations of phosphorus, polyhydoxyalkanoates and glycogen were inhibited by Ag+ other than AgNPs. Ag+ showed stronger toxicity on polyphosphate accumulating organisms (PAOs) than glycogen accumulating organisms (GAOs). Further investigation revealed that the decrease in anaerobic phosphorus release by Ag+ was caused by the inhibition on the activities of adenylate kinase and expolyphosphatase, whereas the decrease in aerobic phosphorus uptake was due to the suppression in energy generation for phosphorus uptake. However, the presence of either AgNPs or Ag+ did not lead to cell leakage and membrane damage.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Yinguang
authors.initials: Y
authors.lastname: Chen
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.forename: Xiong
authors.initials: X
authors.lastname: Zheng
authors.forename: Hui
authors.initials: H
authors.lastname: Mu
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000378:metabolism; D000263:Adenylate Kinase / Q000378:metabolism; D001419:Bacteria / Q000187:drug effects* / Q000378:metabolism; D058491:Bacterial Load; D053768:Metal Nanoparticles; D010758:Phosphorus / Q000378:metabolism*; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012834:Silver / Q000494:pharmacology*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000382:microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification
chemical_list: D017766:Acid Anhydride Hydrolases; D000263:Adenylate Kinase; D010758:Phosphorus; D017856:Phosphotransferases (Phosphate Group Acceptor); D017382:Reactive Oxygen Species; D012834:Silver; D062065:Wastewater; D014874:Water Pollutants, Chemical; C022424:polyphosphate kinase; C020137:exopolyphosphatase