నైరూప్య

Ionic characteristics of river Ganga, Yamuna and their canals: Ultimate level of ions in the drinking water supply

J.S.Jangwan, N.Semwal

The chemistry of fresh water is dictated mainly by ions. Composition of ions in Himalayan Rivers is predominantly governed by chemical weathering process. Calcium and magnesium were the major ions, accounting for more than 85% of the total cation concentration of 1.408844331meq./l in River Ganga and 1.063554785 meq./l in River Yamuna. Among rest 15% sodium was the most abundant ion followed by trace quantities of potassium and ammonium ions. Total cation levels were increased to 2.115125212 meq./l and 3.085396688 meq./l in Gang Canal and Western Yamuna Canal respectively, having same pattern of ions. The levels of calcium and magnesium ions in drinking water supply of these canals were also in the range of 78 - 84% of the total concentration of 3.0 meq./l approx. Bicarbonate and sulphate were the major ions accounting for 86% of total anion concentration of 1.499494169 meq./l in River Ganga and 1.084299371 meq./l in River Yamuna. The levels of bicarbonate and sulphate were raised to 92-94% of total anion concentration of 2.164310984 meq /l in Gang Canal and 2.99235742 meq./l in Western Yamuna Canal. Chloride is the next most abundant ion followed by trace quantities of nitrates. Sulphur springs located in the high altitude region are the prominent source of bicarbonate, sodium and chloride ions respectively to both these rivers. Levels of bicarbonate and sulphate present in drinking water supplywere at 75-83%of total anion concentration (3.0meq./l approx.). The ionic levels found in rivers supporting high diversity of aquatic life was slightly lower compared to drinking water supply for human consumption.