title: Regulatory role of n-propanol in propylene glycol biomethanization under overload.
abstract: This work examines the transient response of an anaerobic fluidized bed bioreactor to an overload of propylene glycol (PG), the primary component in aircraft de-icing waste. Under favorable operating conditions, PG was converted to n-propanol (n-PrOH) and propionate (HPr), and subsequently n-PrOH was completely converted into HPr. HPr was then fully degraded to methane and carbon dioxide via acetate. Under an overload condition, n-PrOH conversion to propionate was completely blocked but propionate degradation continued, contrary to free-energy computations in which n-PrOH should rapidly degrade and HPr should accumulate. When the imposed overload condition was relieved, the accumulated n-PrOH was rapidly converted into propionate. n-PrOH, then, could act as a temporal sink for reducing equivalents (XH(2)) and could regulate the overall PG methanazation process. n-PrOH should be monitored along with typical VFAs such as HPr to avoid sudden VFA accumulation and thus to optimize process performance for PG methanization.
authors.affiliation: Department of Civil and Environmental Engineering, 319 MRC, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA. seokj2@alum.rpi.edu
authors.forename: Jonghyuk
authors.initials: J
authors.lastname: Seok
authors.forename: Simeon J
authors.initials: SJ
authors.lastname: Komisar
mesh_terms: D000401:Aircraft; D001421:Bacteria, Anaerobic / Q000502:physiology; D001673:Biodegradation, Environmental; D019149:Bioreactors; D007053:Ice; D008697:Methane / Q000032:analysis / Q000737:chemistry; D019946:Propylene Glycol / Q000737:chemistry / Q000378:metabolism*; D012997:Solvents / Q000737:chemistry / Q000378:metabolism*
chemical_list: D007053:Ice; D012997:Solvents; D019946:Propylene Glycol; D008697:Methane