title: Treatment of ferrous-NTA-based NO x scrubber solution by an up-flow anaerobic packed bed bioreactor.
abstract: A bench scale system consisting of an up-flow packed bed bioreactor (UAPBR) made of polyurethane foam was used for the treatment and regeneration of aqueous solution of ferrous-NTA scrubbed with nitric oxide (NO). The biomass in the UAPBR was sequentially acclimatized under denitrifying and iron reducing conditions using ethanol as electron donor, after which nitric oxide (NO) gas was loaded continuously to the system by absorption. The system was investigated for different parameters viz. pH, removal efficiency of nitric oxide, biological reduction efficiency of Fe(II)NTA-NO and COD utilization. The Fe(II)NTA-NO reduction efficiency reached 87.8 % at a loading rate of 0.24 mmol L(-1) h(-1), while the scrubber efficiency reached more than 75 % with 250 ppm NO. Stover-Kincannon and a Plug-flow kinetic model based on Michaelis-Menten equation were used to describe the UAPBR performance with respect to Fe(II)NTA-NO and COD removal. The Stover-Kincannon model was found capable of describing the Fe(II)NTA-NO reduction (R m = 8.92 mM h(-1) and K NO = 11.46 mM h(-1)) while plug-flow model provided better fit to the COD utilization (U m = 66.62 mg L(-1) h(-1), K COD = 7.28 mg L(-1)). Analyses for pH, Fe(III)NTA, ammonium, nitrite concentration, and FTIR analysis of the medium samples indicated degradation of NTA, which leads to ammonium and nitrite accumulation in the medium, and affect the regeneration process.
authors.affiliation: Environmental Biotechnology Division, CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur, 440020, Maharashtra, India.
authors.forename: B
authors.initials: B
authors.lastname: Chandrashekhar
authors.forename: Nidhi
authors.initials: N
authors.lastname: Sahu
authors.forename: Heena
authors.initials: H
authors.lastname: Tabassum
authors.forename: Padmaraj
authors.initials: P
authors.lastname: Pai
authors.forename: Amruta
authors.initials: A
authors.lastname: Morone
authors.forename: R A
authors.initials: RA
authors.lastname: Pandey
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D052918:Environmental Restoration and Remediation / Q000295:instrumentation / Q000379:methods*; D005296:Ferrous Compounds / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D009569:Nitric Oxide / Q000737:chemistry / Q000378:metabolism*; D009571:Nitrilotriacetic Acid / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005296:Ferrous Compounds; D009569:Nitric Oxide; D009571:Nitrilotriacetic Acid