title: pH-gradient real-time aeration control for nitritation community selection in a non-porous hollow fiber membrane biofilm reactor (MBfR) with dilute wastewater.
abstract: Nitritation (ammonium to nitrite) as a pre-treatment of Anammox (anaerobic ammonium oxidation) is a key step for an energy-efficient nitrogen-removal alternative from dilute wastewaters, e.g. anaerobically-treated sewage, with which limited study has achieved sustainable nitritation at ambient temperature and short hydraulic retention times. To this end, pH-gradient real-time aeration control in an oxygen-based membrane biofilm reactor was observed at 20°C in the sequencing batch mode. An optimum oxygen supply via diffusion for ammonium-oxidizing bacteria (AOB) was established, but nitrite-oxidizing bacteria (NOB) could be inhibited. The system achieved nitrite accumulation efficiencies varying from 88% to 94% with the aeration control. Mass balance and rate performance analyses indicate that this aeration control is able to supply an oxygen rate of 1.5 mol O(2) mol(-1) ammonium fed, the benchmark oxygenation rate based on stoichiometry for nitritation community selection. Microbial analyses confirmed AOB prevalence with NOB inhibition under this aeration control.
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China. phlee@polyu.edu.hk
authors.forename: Po-Heng
authors.initials: PH
authors.lastname: Lee
authors.forename: Samuel F
authors.initials: SF
authors.lastname: Cotter
authors.forename: Silvia C
authors.initials: SC
authors.lastname: Reyes Prieri
authors.forename: Dinu
authors.initials: D
authors.lastname: Attalage
authors.forename: Shihwu
authors.initials: S
authors.lastname: Sung
mesh_terms: D001419:Bacteria / Q000378:metabolism; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology*; D005374:Filtration / Q000295:instrumentation / Q000379:methods; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D009573:Nitrites / Q000378:metabolism; D016062:Porosity; D018892:Proton-Motive Force; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology*
chemical_list: D008567:Membranes, Artificial; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D062065:Wastewater