title: Comparison of the MBBR denitrification carriers for advanced nitrogen removal of wastewater treatment plant effluent.
abstract: The moving bed biofilm reactors (MBBRs) were used to remove the residual NO3(-)-N of wastewater treatment plant (WWTP) effluent, and the MBBR carriers for denitrification were compared. The results showed that high denitrification efficiency can be achieved with polyethylene, polypropylene, polyurethane foam, and haydite carriers under following conditions: 7.2 to 8.0 pH, 24 to 26 °C temperature, 12 h hydraulic retention time (HRT), and 25.5 mg L(-1) external methanol dosage, while the WWTP effluent total nitrogen (TN) was between 2.6 and 15.4 mg L(-1) and NO3(-)-N was between 0.2 and 12.6 mg L(-1). The MBBR filled with polyethylene carriers had higher TN and NO3(-)-N removal rate (44.9 ± 19.1 and 83.4 ± 13.0%, respectively) than those with other carriers. The minimum effluent TN and NO3(-)-N of polyethylene MBBR were 1.6 and 0.1 mg L(-1), respectively, and the maximum denitrification rate reached 23.0 g m(-2) day(-1). When chemical oxygen demand (COD)/TN ratio dropped from 6 to 4, the NO3(-)- N and TN removal efficiency decreased significantly in all reactors except for that filled with polyethylene, which indicated that the polyethylene MBBR can resist influent fluctuation much better. The three-dimensional excitation-emission matrix analysis showed that all the influent and effluent of MBBRs contain soluble microbial products (SMPs)-like organics and biochemical oxygen demand (BOD), which can be removed better by MBBRs filled with haydite and polyethylene carriers. The nitrous oxide reductase (nosZ)-based terminal restriction fragment length polymorphism (T-RFLP) analysis suggested that the dominant bacteria in polyethylene MBBR are the key denitrificans.
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, No. 8 Da Yang Fang, Anwai, Chaoyang District, 100012, Beijing, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Yuan
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.forename: Qianyu
authors.initials: Q
authors.lastname: Hang
authors.forename: Yangfan
authors.initials: Y
authors.lastname: Deng
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.forename: Chunmei
authors.initials: C
authors.lastname: Li
authors.forename: Shengzhi
authors.initials: S
authors.lastname: Zheng
mesh_terms: D018441:Biofilms; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D058440:Denitrification; D009584:Nitrogen / Q000302:isolation & purification*; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater / Q000032:analysis; D018508:Water Purification / Q000379:methods*
chemical_list: D009584:Nitrogen; D062065:Wastewater