Table 4 Mean values of the Physico-chemical parameters, heavy metals and E. coli of the analysed samples.
S/N | Parameters | Direct rainwater from the sky (control) | Rainwater from Asbestos roof | WHO, 2011 | USEPA, 2012 | NSDWQ, 2015 | ||
|---|---|---|---|---|---|---|---|---|
RWECU | RWECR | RWEDU | RWEDR | |||||
1. | pH | 7.40 ± 0.20 | 7.60 ± 0.20 | 7.50 ± 0.20 | 7.40 ± 0.20 | 6.5–8.5 | 6.5–8.5 | 6.5–8.5 |
2. | Electrical Conductivity, µs/cm | 23.00 ± 4.34 | 20.33 ± 3.52 | 34.33 ± 1.00 | 32.00 ± 4.36 | 1200 | 1000 | 1000 |
3. | Temperature, oC | 22.00 ± 1.00 | 21.00 ± 1.00 | 28.00 ± 1.00 | 21.00 ± 1.00 | 30 | Ambient | Ambient |
4. | TDS, mg/L | 16.67 ± 3.51 | 25.00 ± 3.76 | 45.00 ± 2.65 | 41.33 ± 3.51 | 250 | 500 | 500 |
5. | TSS, mg/L | 17.33 ± 10.10 | 15.67 ± 1.53 | 28.30 ± 5.51 | 19.00 ± 6.86 | 250 | 500 | 500 |
6. | Colour, TCU | 0.48 ± 0.02 | 0.44 ± 0.01 | 0.51 ± 0.34 | 2.32 ± 1.82 | 5 | 15 | 15 |
7. | Phosphate, mg/L | 1.23 ± 0.83 | 2.69 ± 1.12 | 2.42 ± 1.29 | 3.29 ± 1.47 | 5 | 5 | 5 |
8. | Chloride, mg/L | 7.89 ± 1.06 | 8.48 ± 2.09 | 10.83 ± 0.12 | 10.33 ± 2.80 | 250 | 250 | 250 |
9. | Sulphate, mg/L | 3.14 ± 0.95 | 1.07 ± 0.12 | 0.89 ± 0.20 | 0.95 ± 0.24 | 250 | 250 | 250 |
10. | Alkalinity, mg/L | 25.33 ± 7.02 | 20.00 ± 2.00 | 48.67 ± 3.06 | 27.00 ± 3.46 | 100 | 200 | 100 |
11. | Nitrate, mg/L | 0.48 ± 0.22 | 0.44 ± 0.01 | 0.51 ± 0.06 | 2.32 ± 1.82 | 50 | 50 | 50 |
12. | E. Coli Count, cfu/mL | ND | ND | ND | ND | 0 | 0 | 0 |
13. | Lead, mg/L | ND | ND | ND | 0.01 ± 0.00 | 0.01 | 0.01 | 0.01 |
14. | Chromium, mg/L | 0.01 ± 0.00 | 0.02 ± 0.01 | 0.01 ± 0.00 | 0.01 ± 0.00 | 0.05 | 0.05 | 0.05 |
15. | Iron, mg/L | 0.01 ± 0.00 | 0.02 ± 0.00 | 0.01 ± 0.00 | 0.01 ± 0.00 | 0.3 | 0.3 | 0.3 |
16. | Aluminium, mg/L | ND | ND | ND | ND | 0.1–0.2 | 0.2 | 0.2 |
