title: Rapid startup and high rate nitrogen removal from anaerobic sludge digester liquor using a SNAP process.
abstract: In this study, a single-stage autotrophic nitrogen removal reactor, packed with a novel acrylic fiber biomass carrier material (Biofix), was applied for nitrogen removal from sludge digester liquor. For rapid start-up, conventional activated sludge was added to the reactor soon after the attachment of anammox biomass on the Biofix carriers, which allowed conventional activated sludge to form a protective layer of biofilm around the anammox biomass. The Nitrogen removal efficiency reached 75% within 1 week at a nitrogen loading rate of 0.46 kg-N/m(3)/day for synthetic wastewater treatment. By the end of the synthetic wastewater treatment period, the maximum nitrogen removal rate had increased to 0.92 kg-N/m(3)/day at a nitrogen loading rate of 1.0 kg-N/m(3)/day. High nitrogen removal rate was also achieved during the actual raw digester liquor treatment with the highest nitrogen removal rate being 0.83 kg-N/m(3)/day at a nitrogen loading rate of 0.93 kg-N/m(3)/day. The thick biofilm on Biofix carriers allowed anammox bacteria to survive under high DO concentration of 5-6 mg/l resulting in stable and high nitrogen removal performance. FISH and CLSM analysis demonstrated that anammox bacteria coexisted and surrounded by ammonium oxidizing bacteria.
authors: Key Laboratory of Industrial Ecology and Environmental Engineering, MOE, School of Environmental Science and Technology, Dalian University of Technology, No. 2 Linggong Road, Dalian, P. R. China. qs_cyj@yahoo.com.cn
authors: Sen
authors: S
authors: Qiao
authors: Takashi
authors: T
authors: Nishiyama
authors: Tatsuo
authors: T
authors: Fujii
authors: Zafar
authors: Z
authors: Bhatti
authors: Kenji
authors: K
authors: Furukawa
mesh_terms: D000179:Acrylates / Q000737:chemistry; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D018441:Biofilms / Q000254:growth & development*; D018533:Biomass; D019149:Bioreactors; D052837:Chemoautotrophic Growth; D015342:DNA Probes; D004269:DNA, Bacterial / Q000032:analysis; D017404:In Situ Hybridization, Fluorescence; D018613:Microscopy, Confocal; D009584:Nitrogen / Q000378:metabolism*; D009606:Nitrosomonas / Q000502:physiology*; D061328:Planctomycetales / Q000502:physiology*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid
chemical_list: D000179:Acrylates; D015342:DNA Probes; D004269:DNA, Bacterial; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D009584:Nitrogen