Table 3 Mean values of the Physico-chemical parameters, heavy metals and E. coli of the analysed samples.
S/N | Parameters | Rainwater from Long span aluminium roof | Rainwater from Stone-coated tiles roof | WHO, 2011 | USEPA, 2012 | NSDWQ, 2015 | ||
|---|---|---|---|---|---|---|---|---|
RWEAU | RWEAR | RWEBU | RWEBR | |||||
1. | pH | 6.50 ± 0.10 | 6.80 ± 0.20 | 6.70 ± 0.10 | 6.90 ± 0.20 | 6.5–8.5 | 6.5–8.5 | 6.5–8.5 |
2. | Electrical Conductivity, µs/cm | 62.67 ± 3.79 | 72.33 ± 6.11 | 43.30 ± 5.69 | 67.30 ± 3.79 | 1200 | 1000 | 1000 |
3. | Temperature, oC | 21.30 ± 1.53 | 20.00 ± 1.00 | 28.00 ± 1.00 | 25.00 ± 1.00 | 30 | Ambient | Ambient |
4. | TDS, mg/L | 42.67 ± 2.08 | 32.00 ± 2.65 | 37.30 ± 3.06 | 29.67 ± 2.52 | 250 | 500 | 500 |
5. | TSS, mg/L | 41.67 ± 14.67 | 36.67 ± 11.59 | 25.30 ± 9.61 | 21.00 ± 4.36 | 250 | 500 | 500 |
6. | Colour, TCU | 0.46 ± 0.18 | 0.97 ± 0.27 | 9.45 ± 0.34 | 8.14 ± 2.54 | 5 | 15 | 15 |
7. | Phosphate, mg/L | 3.80 ± 1.57 | 1.79 ± 1.13 | 5.39 ± 1.22 | 3.97 ± 0.90 | 5 | 5 | 5 |
8. | Chloride, mg/L | 8.54 ± 1.09 | 9.09 ± 1.81 | 7.27 ± 0.01 | 7.29 ± 0.01 | 250 | 250 | 250 |
9. | Sulphate, mg/L | 4.27 ± 1.25 | 3.99 ± 0.76 | 3.43 ± 0.90 | 3.48 ± 1.11 | 250 | 250 | 250 |
10. | Alkalinity, mg/L | 28.00 ± 5.56 | 21.67 ± 3.51 | 28.00 ± 4.00 | 16.67 ± 3.06 | 100 | 200 | 100 |
11. | Nitrate, mg/L | 4.27 ± 1.25 | 3.99 ± 0.76 | 3.43 ± 0.90 | 3.48 ± 1.11 | 50 | 50 | 50 |
12. | E. Coli Count, cfu/mL | ND | ND | ND | ND | 0 | 0 | 0 |
13. | Lead, mg/L | 0.01 ± 0.00 | 0.01 ± 0.00 | ND | ND | 0.01 | 0.01 | 0.01 |
14. | Chromium, mg/L | 0.01 ± 0.00 | ND | 0.01 ± 0.00 | ND | 0.05 | 0.05 | 0.05 |
15. | Iron, mg/L | 0.02 ± 0.01 | 0.01 ± 0.00 | 0.02 ± 0.01 | 0.16 ± 0.05 | 0.3 | 0.3 | 0.3 |
16. | Aluminium, mg/L | ND | ND | ND | ND | 0.1–0.2 | 0.2 | 0.2 |
