Performance of Combined A/O Moving-Bed Biofilm Reactors for Biological Nutrients Removal from Domestic Wastewater under Different Gas/Water Ratios

Table 2

Performance of A/O system under different gas/water ratios.

Gas/water ratio	Chemical oxygen demand (COD)			Ammonium (NH4^+-N)			Total nitrogen (TN)			Total phosphorus (TP)
	Average influent value (mg/L)	Average effluent value (mg/L)	Average removal efficiency value (%)	Average influent value (mg/L)	Average effluent value (mg/L)	Average removal efficiency value (%)	Average influent value (mg/L)	Average effluent value (mg/L)	Average removal efficiency value (%)	Average influent value (mg/L)	Average effluent value (mg/L)	Average removal efficiency value (%)
5 : 1	307.23	25.90	91.27	40.74	4.34	88.77	46.74	20.50	55.46	4.10	1.01	73.05
7 : 1	313.33	12.98	95.56	36.45	0.87	97.27	44.60	9.08	78.67	3.86	0.57	84.49
10 : 1	320.73	12.10	96.16	38.75	0.36	98.98	40.73	20.15	49.46	2.74	1.52	42.32
15 : 1	319.93	8.53	97.08	37.17	0.25	99.24	43.43	22.03	48.44	3.68	2.46	32.47
20 : 1	292.67	6.97	97.51	46.53	0.20	99.56	52.07	28.40	45.33	3.57	2.65	25.02