For estimation of heavy metals in water, 500 ml of water sample (pre acidified) was filtered and subjected to nitric
acid digestion.
For digestion, 5 ml of 6N HNO3 was added to 100 ml of the sample followed by heating to slow boil
till the digestion was completed which was indicated by a light coloured clear solution.
The digested samples were
used for metal estimation using Atomic Absorption Spectrophotometer (MODEL No. SL 173, ELICKO, India) as
per [12].
The heavy metals were estimated i.e. Copper (Cu), Chromium (Cr), Lead Pb) and Zinc (Zn).