Actual Application of a H₂-Based Polyvinyl Chloride Hollow Fiber Membrane Biofilm Reactor to Remove Nitrate from Groundwater

Table 3

Electronic-equivalent fluxes for sulfate and nitrate.

Period	Denitrification rate or; substrate flux^a			Electron-equivalent flux; (eq/m^2d)				Distribution of electron-equivalent; fluxes (%)
	Nitrate (g/m^2d)	Sulfate (g /m^2d)	O2 (g/m^2d)	Nitrate^b	Sulfate^c		Sum-up of the fluxes	Nitrate	Sulfate	O2
Run I	0.49	0.45	0.15	0.18	0.04	0.02	0.23	76.0	15.9	8.1
Run II	0.98	0.75	0.15	0.35	0.06	0.02	0.43	81.5	14.2	4.3
Run III	1.18	0.97	0.15	0.42	0.08	0.02	0.52	81.2	15.2	3.6

Calculated by influent flow rate () × removed substrate ()area of biofilm surface (), where Q is in m³/d, S is in g-substrate (-N or )/m³, is in m², and J is in g--N/m²d or g-/m²d.
^bCalculated by = (influent flow rate () × removed -N ())/(area of biofilm surface () × EW_Nitrate), where is in m³/d, is in g--N/m³, is in m², EW_Nitrate is in 14 g--N/5 e⁻ equivalent for reduction of nitrate to nitrogen gas, and is in g--N/m²d. We assume five electrons per mole for nitrate reduction to nitrogen gas.
^cCalculated by (influent flow rate () × removed ())/(area of biofilm surface () × EW_Sulfate), where Q is in m³/d, ΔS is in g-/m³, is in m², EW_Sulfate is in 96 g--N/8 e⁻ equivalent for reduction of sulfate to sulfide, and J is in g-/m²d. We assume 8 electrons per mole for sulfate reduction to sulfide, for seen   (i) [26].
^dCalculated by (influent flow rate () × removed O₂ ())/(area of biofilm surface () × EW_Oxygen), where Q is in m³/d, ΔS is in g-O/m³, is in m², EW_Oxygen is in 32 g-O₂/4 e⁻ equivalent for reduction of O₂ to O²⁻, and J is in g-O₂/m²d. We assume 4 electrons per mole for reduction O₂ to O²⁻, for seen   (ii).