Parameters | Units | WHO standard (2011) | Weight (wi) | Relative weight \({W_{i}} = \frac{{{\text{w}}_{\text{i}} }}{{\mathop \sum \nolimits_{{{\text{i}} = 1}}^{\text{n}} {\hbox{w}}_{\text{i}} }}\) |
---|---|---|---|---|
pH |  | 6.5–8.5 | 4 | 0.093 |
TDS | mg/L | 500 | 4 | 0.093 |
SO42− | mg/L | 250 | 4 | 0.093 |
Ca | mg/L | 75 | 2 | 0.047 |
Mg | mg/L | 50 | 2 | 0.047 |
Total harness | mg/L | 500 | 3 | 0.070 |
NO3− | mg/L | 45 | 5 | 0.116 |
Fe | mg/L | 0.3 | 3 | 0.070 |
Zn | mg/L | 3.0 | 3 | 0.070 |
Na+ | mg/L | 200 | 1 | 0.023 |
K+ | mg/L | 12 | 1 | 0.023 |
Cl− | mg/L | 250 | 5 | 0.116 |
HCO3− | mg/L | 300 | 3 | 0.070 |
EC | μS/cm | 500 | 3 | 0.070 |
 |  |  | \(\sum {\text{w}}_{\text{i}}\) = 43 | \(\sum {\text{w}}_{\text{i}}\) = 1 |