| dc.description | Water quality is characterized in terms of the chemical, physical, biological and
radiological properties of water. There are several factors that affect water
quality. The quality of natural water is related to the quality of recharge water,
the mineralogy of soils and aquifer sediments, and the residence time in the
ground water flow system, and the presence of nearby saline water. However,
the primary influence on groundwater quality (as well as surface water quality)
is the contamination brought about by urban storm water, agricultural runoff,
domestic wastewater, industrial wastewater, and hydrologic modifications and
human activity are the major sources, which govern the water quality. | en_US |
| dc.description.abstract | An investigation was carried out to assess the quality of 75 water samples of which 68 samples
were groundwater and 7 were from surface sources collected from Dinajpur Sadar. The chemical
analyses results were used to determine the hydrogeochemical processes of differentions for
their suitability for irrigation and drinking water samples were analysed for pH, electrical
conductivity (EC), cations (Ca**, Mg**, Na*, K*, Zn?*, Cu’*, Mn** and Fe**), anions (CO3”,
HCO;3, NO;3, S04”, PO, and Cl) and TDS (total dissolved solids). Several variables were
compated such as SAR (sodium adsorption ratio), SSP (soluble sodium percentage), RSC
(residual sodium carbonate), permeability index (PI), Kelly's ratio, potential salinity, Gibbs ratio
and hardness to evaluate the suitability of groundwater supply for specific uses. The pH values
indicated that the waters were mostly acidic in nature. From the geochemical results, it has been
found both the cations and anions varied in the groundwater. The average values of Mg and Cl
was 2.22 meq L” and 1.84 meqL'. Among the chemical budget of ions, Mg and Cl were found
to be the most predominant ions. The average value of Ca, Na, K and HCO3 were 1.65 meq Cs
2.10 meq L”, 0.05 meq L"!, and 3.06 meq L" respectively. The above values of these samples
were safe limit for crop production. The intense agricultural activities may be an important factor
for the higher NO3 concentration in these aquifers. The mean values of TDS and SAR were
165.8 mg L’! and 1.58. As per TDS all the waters were excellent and SAR indicated the excellent
category for irrigation purpose. Based on SSP all waters were excellent classes. In respect to
hardness, water had moderately hard to very hard class. Based on the total hardness, most ground
waters are moderately hard. All waters were free from RSC and belong to the suitable category.
According to EC and SAR the most dominant class is Cl-S1. The major ion concentrations are
below the acceptable level for drinking water. The salinity hazard is low thus, there is less
chances to increase of toxic salt concentrations. Other micronutrient like Fe, Zn, Mn and Cu
were within the safe limits for irrigating all types of agricultural crops. Some samples had high
concentration of Fe and Mn that exceeded the drinking standard. Other ions likes Cl, Cu, Zn and
SO, were within the safe limit. Regarding cation and anion constituents, groundwater is suitable
for irrigation, purposes except of few wells. | en_US |
