title: Nitrification-denitrification biological treatment of a high-nitrogen waste stream for water-reuse applications.
abstract: This research was conducted to evaluate the use of biological nitrification-denitrification systems as pre-processors for recycling wastewater to potable water in support of space exploration. A packed-bed bioreactor and membrane-aerated nitrification reactor were operated in series with a 10:1 recycle ratio over varying loading rates. The dissolved organic carbon (DOC) removal exceeded 80% for all loading rates (theta = 1 to 6.8 days), while total nitrogen removal generally increased with decreasing retention time, with a maximum removal of 55%. The degree of nitrification generally declined with decreasing retention time from a high of 80% to a low of 60%. Maximum DOC and total nitrogen volumetric removal rates exceeded 1000 and 800 g/m3 x d, respectively, and maximum nitrification volumetric conversion rates exceeded 300 g/m3 x d. At low hydraulic loading rates, the system was stoichiometrically limited, while kinetic limitations dominated at high hydraulic loading rates. Incomplete nitrification occurred at high loading rates, likely as a result of the high pH and large concentrations of ammonia.
authors.affiliation: Department of Civil and Environmental Engineering, Texas Tech University, Lubbock, Texas 79409, USA. Andrew.jackson@ttu.edu
authors.forename: W Andrew
authors.initials: WA
authors.lastname: Jackson
authors.forename: Audra
authors.initials: A
authors.lastname: Morse
authors.forename: Eric
authors.initials: E
authors.lastname: McLamore
authors.forename: Ted
authors.initials: T
authors.lastname: Wiesner
authors.forename: Shu
authors.initials: S
authors.lastname: Xia
mesh_terms: D002244:Carbon / Q000302:isolation & purification; D052918:Environmental Restoration and Remediation / Q000379:methods*; D009573:Nitrites / Q000737:chemistry*; D009584:Nitrogen / Q000302:isolation & purification
chemical_list: D009573:Nitrites; D002244:Carbon; D009584:Nitrogen