Effect of Free Nitrous Acid on Nitrous Oxide Production and Denitrifying Phosphorus Removal by Polyphosphorus-Accumulating Organisms in Wastewater Treatment

Table 2

Various rates of denitrifying phosphorus removal by PAOs.

	FNA concentration (mgHNO2-N/L)	Phosphorus uptake rate (mgPO4-P/h·gVSS)		Nitrite reduction rate (mgNO2-N/h·gVSS)	The highest N2O to TN proportion (%)	PHA degradation rate (mmol-C/h·gVSS)	PHA consumption to TN proportion (mmol-C/mmol-N·gVSS)
		Nitrite exit conditions	Average rate of anoxic phase			Nitrite exit conditions	Average rate of anoxic phase
pH 6.0	92.3 × 10^−3	−2.08	−2.08	1.16	18.80	−0.091	-
pH 6.5	31.6 × 10^−3	0.53	0.53	2.14	26.81	0.067	-
pH 7.0	10.3 × 10^−3	6.12	5.38	4.82	40.63	0.278	0.916
pH 7.5	3.10 × 10^−3	9.66	6.13	8.15	78.42	0.589	0.546
pH 8.0	0.96 × 10^−3	11.10	8.10	8.25	61.55	0.581	0.532
pH 8.5	0.35 × 10^−3	15.82	8.62	11.7	44.04	0.603	0.444