Table 1.
UV-treated final effluent water quality parameters of the North End Sewage Treatment Plant
| Sampling time | Mean | Standard deviation | ||||
|---|---|---|---|---|---|---|
| Oct-22-2019 (T1) | Nov-28-2019 (T2) | Dec-18-2019 (T3) | Feb-6-2020 (T4)‡ | |||
| pH | 7.12 | 6.81 | 6.79 | 6.99 | 6.93 | 0.14 |
| Turbidity (NTU) | 12.25† | 4.2 | 6.3 | 9.2 | 7.99 | 3.03 |
| TSS (mg/L) | 19.5† | 6 | 10 | 18 | 13.38 | 5.58 |
| BOD (mg/L) | 19.5† | 13 | 18 | 26 | 19.13 | 4.64 |
| COD (mg/L) | 51.5† | 66 | 94 | 89 | 75.13 | 17.25 |
| TN (mg/L) | 15.4† | 40.7 | 49.8 | 50.5 | 39.1 | 14.22 |
| TP (mg/L) | 1.67† | 3.43 | 1.69 | 1.69 | 2.12 | 0.76 |
| TOC (mg/L) | 19.8† | 21.2 | 29.6 | 34.4 | 26.25 | 6.02 |
| Precipitation (mm)* | 4.8 | 0 | 1 | 1.6 | 1.85 | 1.8 |
| Grab temperature (°C) | 13.4 | 14.1 | 14.1 | 12.7 | 13.6 | 0.7 |
| E. coli (counts/100 mL) | 60 | 60 | 90 | 1080 | 322.5 | 437.51 |
TSS, total suspended solids; BOD, biochemical oxygen demand; COD, chemical oxygen demand; TN, total nitrogen; TP, total phosphorus; TOC, total organic carbon
*Cumulative amount of rainfall over three days
†Parameters measured the day before and the day after were averaged and used to estimate parameters of sample date