The Thoothukudi District is characterized by different geological formations and groundwater is the major source for domestic, agricultural and other water related activities. 100 groundwater samples collected from this area during Pre monsoon (PRM) and Post monsoon (POM). Chemical data were used for mathematical calculations and graphical plots to understand the chemical process like such as Ca2+ + Mg2+ versus SO2-4 + HCO-3 scatter diagram indicate that majority of the samples in ion exchange process due to an excess of SO2-4 + HCO-3 during PRM compared to POM. The (Ca2+ +Mg2+) versus TZ+ plot for both seasons reveals higher Ca2+ and Mg2+ leaching due to silicate mineral weathering from aquifer matrix of the study area. The plot for (Na+ + K+) versus TZ+ indicates weathering process of both alkali and alkali earth from feldspars along with additional sources like contribution from alkali/saline soil and residence time. Na+ versus Cl- plot shows most of the groundwater samples lay above the 1:1 trend line during PRM compared to POM seasons due to excess sodium, which might have come from silicate weathering. Overall, results indicate that different natural hydrogeochemical processes such as simple weathering of carbonate minerals and silicate weathering are the key factors during PRM compared to POM due to dilution effect after rainfall.
Loading....