Table 1.

Summary of microbial As(III) oxidation under denitrifying conditions

Inoculum		As(V) formation‡		Time†
Number	Sources	With NO3−	Without NO3−	(Days)
1	NGS	0.423±0.004	—	6
2	EGS	—	—	—
3	ADS	0.425±0.003	—	13
4	RAS	—	—	—
5	TDE	0.416±0.002	—	10
6	DPS	0.415±0.003	—	6
7	WCS	0.413±0.001	—	5
8	PCS	0.295±0.020	0.298±0.014	>14+

^†Time to oxidize 80% of 0.5 mM As(III) to As(V)

^‡Conversion of As(III) to As(V): “Average ± STDE” for “conversion ≥ 80%”; “—“ for “conversion ≤ 5%”

As(V) formation =conc. of As(V) (at the end of the experiment, d10 or d14) minus conc. of As(V) (at day 0)

⁺In PCS, at day 14 only 60% of As(III) was converted to As(V)