Normality of FAS:
N(FAS) = W/ (TV×0.04904×10)
= 10/ (18.7×0.04904×10) = 1.0904
Observation –
| Burette Reading | Greywater A | Greywater B | Greywater C |
| Bathroom | Kitchen | Azolla bed | |
| 1. | 4.9 | 1.6 | 1.3 |
| 2. | 4.8 | 1.4 | 1.3 |
| 3. | 4.8 | 1.6 | 1.35 |
| Average | 4.83 | 1.53 | 1.32 |
Blank sample reading= 5.6ml
Normality of FAS = 1.09
Sample 1:
COD= [(B-V) × N(FAS)×8000]/vol. of sample
= [(5.6-4.83) × 1.09 ×8000]/ 20
= 335.72 mg/L
Sample 2:
COD= (B-V) × N(FAS)×8000)/vol. of sample
= [(5.6-1.53) × 1.09 × 8000]/20
= 1774.52 mg/L
Sample 3:
COD= (B-V) × N(FAS)×8000)/vol. of sample
= [(5.6-1.32) × 1.09× 8000]/20
= 1866.08 mg/L
we also tested other water properties like pH, hardness, ammonia, turbidity, chloride, fluoride, etc. with the help of Mridaparikshak kit and manual for procedure.
| Type of water | Water properties | ||||||
| pH | Hardness | Ammonia | Fluoride | Chloride | Turbidity | Alkalinity | |
| Grey water | 6 | 250 | 3.5 | 2 | 90 | 100 | 350 |
| Tap water | 7.5 | 80 | 4 | 1 | 50 | – | 200 |
