title: Changes in the nitrogen removal performance and the properties of granular sludge in an Anammox system under oxytetracycline (OTC) stress.
abstract: The short- and long-term effects of oxytetracycline (OTC) on the anaerobic ammonium oxidation (Anammox) process were evaluated. The OTC inhibition of Anammox was substrate-, and especially nitrite-, dependent. The IC50 of OTC in the batch tests on an Anammox mixed culture was calculated to be 517.5 mg L(-1). The long-term effects of OTC on the Anammox process were examined in a continuous-flow upflow anaerobic sludge blanket reactor. Fifty milligrams per liter of OTC significantly decreased the nitrogen removal rate from 12.4 to 2 kg N m(-3) d(-1) within 26 days. The recovery of Anammox performance after OTC inhibition was accelerated by adding biocatalyst. In contrast to the modified Stover-Kincannon model, the modified Boltzmann model accurately simulated the recovery of Anammox performance. OTC presented in the influent led to sludge hardening and cell lysis. A poor settling property of Anammox sludge was also observed.
authors.affiliation: Department of Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, PR China.
authors.forename: Guang-Feng
authors.initials: GF
authors.lastname: Yang
authors.forename: Qian-Qian
authors.initials: QQ
authors.lastname: Zhang
authors.forename: Ren-Cun
authors.initials: RC
authors.lastname: Jin
mesh_terms: D001421:Bacteria, Anaerobic / Q000187:drug effects / Q000502:physiology*; D019149:Bioreactors / Q000382:microbiology; D003198:Computer Simulation; D008954:Models, Biological; D009584:Nitrogen / Q000302:isolation & purification / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010118:Oxytetracycline / Q000494:pharmacology*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*
chemical_list: D000644:Quaternary Ammonium Compounds; D012722:Sewage; D009584:Nitrogen; D010118:Oxytetracycline