Table 2.
Spatial variations of physicochemical parameters of wastewater collected from treated textile effluent discharge canal during the dry season.
| Parameter | Site A | Site B | Site C | Site D | |
|---|---|---|---|---|---|
| pH | 9.06 ± 0.02a | 6.96 ± 0.1b | 6.82 ± 0.07b | 6.74 ± 0.02b | |
| Temperature (°C) | 33.1 ± 0.3a | 31.1 ± 0.2b | 31.1 ± 0.1b | 29.7 ± 0.4b | |
| Conductivity (μS/cm) | 9503 ± 100a | 4457.8 ± 60b | 4432.2 ± 45.3b | 436.67 ± 5.53c | |
| TDS (mg/L) | 5191.10 ± 62.1a | 2345.6 ± 30.9b | 2554.4 ± 98.5b | 207.58 ± 3.89c | |
| DO (mg/L) | 2.30 ± 0.21a | 2.47 ± 0.17a | 2.59 ± 0.15a | 5.65 ± 0.09b | |
| Salinity (‰) | 4.59 ± 0.04a | 2.16 ± 0.03b | 2.15 ± 0.02b | 0.21 ± 0.00c | |
| BOD5 (mg/L) | 36 ± 0.9a | 12 ± 0.3b | 10 ± 0.2b | 6 ± 0.3c | |
| COD (mg/L) | 673 ± 37a | 269 ± 6b | 255 ± 6b | 176 ± 16c | |
| Ammoniacal-N (mg/l) | 3.2 ± 0.1a | 2.9 ± 0.0ab | 2.3 ± 0.0b | 2.4 ± 0.0b | |
| Zn | 42.5 ± 3.5a | 39.6 ± 6.2a | 26.6 ± 3.6b | 8.5 ± 2.1c | |
| Cu | 10.9 ± 1.1a | 8.7 ± 1.2b | 8.5 ± 3.1b | 2.6 ± 0.5c | |
| Colour intensities (m−1) | 436 nm | 16.2 ± 0.1a | 11.4 ± 0.4b | 9.5 ± 0.1c | 8.9 ± 0.1c |
| 525 nm | 8.6 ± 0.1a | 5.8 ± 0.3b | 4.5 ± 0.1c | 4.4 ± 0.1c | |
| 620 nm | 4.5 ± 0.1a | 2.7 ± 0.2b | 2.3 ± 0.0b | 1.9 ± 0.1c | |
Data are presented as mean ± standard deviation (SD). Results indicated by different superscript letters in each row are significantly different from each other (n = 8, ANOVA, Tukey's test, p < 0.05). Site A: effluent discharge point; site B: 100 m downstream from site A, site C: 200 m downstream from site A, and site D: 100 m upstream from site A.