Bacteriological and physicochemical parameters of water flowing from tanks of different ages
| Parameter . | Mean . | SIG. (α = 0.05) . | ||
|---|---|---|---|---|
| Tank age in years . | 0–5 (n = 43) . | 6–10 (n = 22) . | >10 (n = 47) . | |
| Bacteriological analysis | ||||
| Total coliforms (CFU/100 ml) | 12 ± 3 | 17 ± 5 | 26 ± 4 | *0.020 |
| Faecal coliforms (CFU/100 ml) | 0 | 1 | 1 ± 1 | *0.026 |
| Heterotrophic bacteria (CFU/100 ml) | 491 ± 97 | 919 ± 340 | 964 ± 172 | 0.060 |
| Physicochemical analysis | ||||
| Free chlorine (mg/L) | 0.010 ± 0.001 | 0.010 ± 0.001 | 0.030 ± 0.002 | 0.580 |
| Colour (Pt Co) | 7.530 ± 0.740 | 8.140 ± 1.230 | 14.740 ± 2.430 | 0.120 |
| SO42− (mg/L) | 6.66 ± 0.200 | 5.110 ± 0.540 | 5.990 ± 0.300 | *0.042 |
| Mn (mg/L) | 0.009 ± 0.001 | 0.010 ± 0.001 | 0.020 ± 0.001 | *<0.001 |
| Fe (mg/L) | 0.002 ± 0.001 | 0.020 ± 0.001 | 0.140 ± 0.060 | *<0.001 |
| Parameter . | Mean . | SIG. (α = 0.05) . | ||
|---|---|---|---|---|
| Tank age in years . | 0–5 (n = 43) . | 6–10 (n = 22) . | >10 (n = 47) . | |
| Bacteriological analysis | ||||
| Total coliforms (CFU/100 ml) | 12 ± 3 | 17 ± 5 | 26 ± 4 | *0.020 |
| Faecal coliforms (CFU/100 ml) | 0 | 1 | 1 ± 1 | *0.026 |
| Heterotrophic bacteria (CFU/100 ml) | 491 ± 97 | 919 ± 340 | 964 ± 172 | 0.060 |
| Physicochemical analysis | ||||
| Free chlorine (mg/L) | 0.010 ± 0.001 | 0.010 ± 0.001 | 0.030 ± 0.002 | 0.580 |
| Colour (Pt Co) | 7.530 ± 0.740 | 8.140 ± 1.230 | 14.740 ± 2.430 | 0.120 |
| SO42− (mg/L) | 6.66 ± 0.200 | 5.110 ± 0.540 | 5.990 ± 0.300 | *0.042 |
| Mn (mg/L) | 0.009 ± 0.001 | 0.010 ± 0.001 | 0.020 ± 0.001 | *<0.001 |
| Fe (mg/L) | 0.002 ± 0.001 | 0.020 ± 0.001 | 0.140 ± 0.060 | *<0.001 |
*, significance (α = 0.05).