Nitrogen and Phosphorous Removal in Municipal Wastewater Treatment Plants in China: A Review

Table 2

Performance of major WWTP processes in China in 2006 (unit, mg/L).

	COD			NH3–N			TN			TP
	mean^a	range^b	%^c	mean^a	range^b	%^c	mean^a	range^b	%^c	mean^a	range^b	%^c
OD	320	125–550	84%	28	12–46	68%	34	18–58	59%	4.2	1.2–7	71%
SBR	300	120–500	83%	27	10–48	66%	34	15–57	58%	4.0	1.2–6	71%
AAO	390	150–700	85%	32	14–54	75%	39	16–68	55%	5.4	2.0–10	78%
AO	460	140–860	80%	31	11–49	64%	46	19–74	58%	5.3	1.0–9	70%
CAS^d	440	175–790	88%	34	14–58	50%	40	6–86	42%	4.9	1.7–10	66%

^aAverage concentrations of pollutants in raw influent to WWTPs; ^b10 and 90 percentiles in the distribution of pollutant concentrations; ^cRemoval rates based on average values of WWTP influent and effluent; ^dConventional activated sludge processes with primary and secondary treatment.