lower concentration of parameters such as sodium potassium fluoride phosphate analyzed in the water samples of a reservoir is observed whereas the same parameters were found to be higher in the water of other reservoir constructed on the same. what may be the reason
Question is related to surface water, which usually have low concentration of Na, K and F compared to ground water. As I understand, This is concerned with two reservoirs, on comparison the value of Na, K and F differ to each other. As to get better answer of this question one should know the data. Examine how much variation. And what about other parameters. Distance between two reservoirs. Type of geological strata and hydrological processes. Time period between two analysis performed and their accuracy. Water collection in Pre or post Manson. It may also concerned with water - rock interaction and percolation process. Chemical kinetic study can Not be ruled out. Dr. Pavan, appreciate your problem and hopefully result of this may provide valuable information.
The answer depends upon which reservoir is on the up-stream and which is on the down-stream?
If low concentration of these parameters were observed on the up stream reservoir and higher concentration on the downstream reservoir, then there may be a possibility of polluting sourced in between these reservoirs.
Arun, appreciated your comment. As you suggested may be one of the possible cause for variation in particular chemical parameters. It is further suggested to examine other parameters, what they indicate.
the two reservoirs are constructed on the same river.. the analysis is done for 3 years and 11 seasons all the values are well within the prescribed standard values by B IS
but some parameters mentioned in my questions show variation
1. the soils are sandy loams, red soils
2. the distance between 2 reservoirs is 50 km
3. all parameters mentioned above were found to be higher in concentration in the reservoir situated near the originating place of the reservoir through which the water reaches the second reservoir in which the values were found to be lesser
the same trend of higher concentration in the reservoir near the originating place when compared to the other
The water before the 2nd reservoir, may be diluted? If you have hydroxiapatrite in rocks
it absorbs Fluoride as fluoropatite that is less soluble.and harder.
During its travel of 50 km from the 1st to the 2nd reservoir is there any chance of dilution? like some other streams joining the river.
As Prof. Bertello pointed that it can also be influenced by the rock type. It also depends on the aquatic macrophytes. The aquatic macrophytes can take up potassium and phosphorus as nutrients. Some plants are also capable of accumulating Fluoride. Apart from these the adsorption can also play a role. Eventhough if there is no streams joining the main river, the water can still get diluted by the seepage from the soil. These are all possibilities. The exact reason depends upon a lot of variables and is bit complicated. If you consult a statistical expert, they may help you to get some relations between your data, but I am not sure.
Thank you
Always surface waters (if not polluted) have less dissolved solids than groundwater. Same in the case of Na, K and Fluoride. The concentration of particular ion depends on the geology and soil conditions of the area.
The reason for variation of Na, K and F in different reservoirs depends on the geological situation and anthropogenic contamination. We can not pin point exact reason for this, it depends upon lot of environmental and geological variables.
The one of the main reason might be due to dilution effect and mixing of rainwater with surface water than groundwater.