title: [Activity of nitrifiers and metabolized products in a membrane bioreactor MBR under the condition of non-sludge discharge].
abstract: A membrane bioreactor fed with synthetic ammonium bearing inorganic wastewater was operated under the following conditions: HRT, from 30 h to 7 h; influent NH4+ -N, 500 mg/L; non-discharge of sludge. Formation of extra-cellular polymers (ECP) and their influence on the activity of nitrifiers in the membrane bioreactor was investigated. Over the whole experimental period of 200 d, the activity of nitrifiers in terms of overall ammonium-oxidizing rate decreased from 2.1 kg/(L x d) to 1.5 kg/(L x d), and the nitrifier number using INTF absorbency measurement decreased from 0.023 x 10(-3) to 0.01 x 10(-3), although the MLSS increased from 4500 mg/L to 10500 mg/L. The ECP content increased from the initial 300 mg/L to 600 mg/L. Batch tests using the extracted ECP also indicated that the activity of nitrifiers could be inhibited by the existence of ECP.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Hong-yan
authors.initials: HY
authors.lastname: Li
authors.forename: Meng-chun
authors.initials: MC
authors.lastname: Gao
authors.forename: Qing-xiang
authors.initials: QX
authors.lastname: Yang
authors.forename: Min
authors.initials: M
authors.lastname: Yang
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D041841:Bradyrhizobiaceae / Q000378:metabolism*; D008567:Membranes, Artificial; D009573:Nitrites / Q000378:metabolism*; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D009573:Nitrites; D012722:Sewage