Autohydrogenotrophic perchlorate reduction kinetics of a microbial consortium in the presence and absence of nitrate.
This is the first study to model the effects of nitrate on autohydrogenotrophic perchlorate biokinetics. Batch experiments demonstrated that the presence of nitrate significantly inhibited perchlorate degradation by a hydrogen-oxidizing, perchlorate-reducing microbial consortium. However, the consortium was capable of significant perchlorate reduction while the bulk of the nitrate was still present. Results showed that a modified competitive inhibition model successfully predicted autohydrogenotrophic perchlorate degradation in the presence of nitrate (initial concentrations of ∼230 μg ClO(4)(-)/L and 2.2-4.6 mg NO(3)(-)-N/L). The model describes perchlorate degradation as a function of the biomass, perchlorate, hydrogen, and nitrate concentrations, as well as the single-component perchlorate (28 μg/L), hydrogen (2.3 × 10(-6) M (aq)), and nitrate (0.15 mg/L as N) half-saturation coefficients (K(s)) and perchlorate maximum substrate utilization rate (k) (1.8 μg ClO(4)(-)/mg TSS-hr). Single-component parameters were obtained through a series of batch experiments performed under perchlorate-, nitrate-, and hydrogen-limiting conditions with initial concentrations of 80-340 μg ClO(4)(-)/L, 2.7-3.6 mg NO(3)(-)-N/L, and 1%-3% H(2) (g) by volume.
Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, 1 University Station C1786, Austin, TX 78712-0273, USA.
Mara R
MR
London
Susan K
SK
De Long
Mark D
MD
Strahota
Lynn E
LE
Katz
Gerald E
GE
Speitel
D001419:Bacteria / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D061249:Batch Cell Culture Techniques; D001673:Biodegradation, Environmental / Q000187:drug effects; D006859:Hydrogen / Q000378:metabolism*; D007700:Kinetics; D008956:Models, Chemical; D009566:Nitrates / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects; D010472:Perchlorates / Q000378:metabolism*; D010802:Phylogeny
D009566:Nitrates; D010472:Perchlorates; D006859:Hydrogen; C494474:perchlorate