Table 1. Characteristics of 18 wastewater treatment plants.
| ID | WWTP |
Percentage (%) of municiple wastewater | Process | Flow rate (103 m3/d) | Average (or range) (mg/L) |
Latitude | Longitude | Temperature (oC) |
Sampling time (mm/year) | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Code | Full name | COD | TN | TP | Range | At sampling | |||||||
| 1 | UK-WL-OW | Wanlip Old Works (Leicester, UK) | Predominant | A/A/O | 95 | 657 | 38 | 8 | N52.4 | W1.6 | 10–20 | NAb | 11/2012 |
| 2 | UK-NW-NW | Crankley Point (Newark, UK) | Significant trade | CAS | 11 | 1302 | 34 | 6.5 | N53.0 | E0.5 | 10–20 | NA | 11/2012 |
| 3 | UK-SB-SB | Stoke Bardolph (Nottingham, UK) | Predominant | CAS | 142 | 532 | 35 | 6.2 | N52.6 | W1.2 | 10–20 | NA | 11/2012 |
| 4 | UK-LB-LB | Loughborough (Loughborough, UK) | Predominant | A/O + RAS fermentation | 23 | 452 | 34 | 5.5 | N52.5 | W1.1 | 10–20 | NA | 11/2012 |
| 5 | US-CO-CO | Columbia regional(Columbia, USA) | Predominant | CAS | 76 | 700 (500–1100) | 32 (21–42) | NA | N38.9 | W92.2 | 11–23 | 17 | 04/2010 |
| 6 | US-GR-PC | Potato Creek (Griffin, USA) | Predominant | OD | 8 | 402 | 30 | 4.0 | N33.2 | W84.2 | 15–20 | 18 | 05/2010 |
| 7 | CA-GP-GP | Guelph (Guelph, Canada) | Predominant | CAS | 55 | 270 | 45 | 7.0 | N43.5 | W80.2 | 13–23 | 13 | 01/2010 |
| 8 | JP-A2O-TKa | (Tsukuba, Japan) | Predominant | A/A/O | 10 | 102 | 37 | 3.9 | N36.1 | E140.1 | 11–24 | 19 | 09/2012 |
| 9 | JP-STD-TKa | (Tsukuba, Japan) | Predominant | CAS | 14 | 102 | 37 | 3.9 | N36.1 | E140.1 | 11–24 | 19 | 09/2012 |
| 10 | SG-SG-UP | Ulu Pandan (Singapore) | Predominant | CAS + MBR | 23 | 265 | 45 | 9.2 | N1.3 | E103.6 | 23–32 | 27 | 05/2010 |
| 11 | CN-BJ-BX | Bei-Xiao-He (Beijing, PRC) | 95 | A/A/O + MBR | 100 | 462 | 51 | 9.3 | N39.9 | E116.4 | 16–25 | 16 | 12/2009 |
| 12 | CN-NJ-SJ | Suo-Jin-Cun (Nanjing, PRC) | 85 | A/O | 15 | 330 | 57 | 5.8 | N32.1 | E118.6 | 16–29 | 22 | 11/2009 |
| 13 | CN-SH-MH | Min-Hang (Shanghai, PRC) | 70 | A/O | 44 | 267 (140–576) | 40 (34–53) | 2.9 (2–6) | N31.2 | E121.3 | 12–28 | 16 | 11/2009 |
| 14 | CN-GZ-DT | Da-Tan-Sha (Guangzhou, PRC) | 60 | A/A/O | 150 | 595 | 55 | 5.2 | N23.1 | E113.2 | 20–30 | 26 | 04/2010 |
| 15 | CN-WH-LW | Long-Wang-Zui (Wuhan, PRC) | Predominant | A/A/O | 161 | 277 | 23 | 4.9 | N30.5 | E114.3 | 16–29 | 17 | 12/2009 |
| 16 | CN-QD-TD | Tuan-Dao (Qingdao, PRC) | 70 | A/O | 100 | 900 | 120 | 10.0 | N36.1 | E120.2 | 12–20 | 17 | 12/2009 |
| 17 | CN-HK-ST | Sha-Tin (Hong Kong, PRC) | 95 | A/O | 216 | 226–491 | 26–40 | 3.1–5.3 | N22.3 | E114.2 | 22–32 | 27 | 11/2009 |
| 18 | CN-HK-SH | Shek-Wu-Hui (Hong Kong, PRC) | 90 | A/O | 82 | 206–529 | 28–41 | 3.0–5.6 | N22.3 | E114.1 | 21–31 | 30 | 08/2010 |
Abbreviations: WWTP, wastewater treatment plant; COD, chemical oxygen demand; TN, total nitrogen; TP, total phosphorus; CAS, conventional activated sludge; A/A/O, anaerobic/anoxic/aerobic; A/O, anoxic/aerobic; MBR, membrane bioreactor; OD: oxidation ditch.
aJP-A2O-TK and JP-STD-TK were from one sewage treatment plant in Tsukuba (Japan), but the activated sludge samples were extracted from two different treatment pipelines using A/A/O process and CAS process respectively.
bNA indicated not applicable. The temperatures at sampling UK-WL-OW, UK-NW-NW, UK-SB-SB, UK-LB-LB were assumed to be 15 °C for the correlation analysis according to the average temperature in the WWTPs.