A study on the impact of weathering in groundwater chemistry of a hard rock aquifer
- PDF / 1,947,970 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 10 Downloads / 230 Views
ORIGINAL PAPER
A study on the impact of weathering in groundwater chemistry of a hard rock aquifer V. S. Adithya 1 & S. Chidambaram 1 & C. Thivya 1 & R. Thilagavathi 1 & M. V. Prasanna 2 & M. Nepolian 1 & N. Ganesh 1
Received: 18 November 2014 / Accepted: 10 September 2015 # Saudi Society for Geosciences 2016
Abstract Hydrogeochemistry of groundwater in hard rock terrain are mainly governed by lithology and land use practices. A study area near Madurai region of central Tamil Nadu was selected with various litho-units and a hard rock sedimentary contact with an unconformity. Land use practices in these regions are also varied with lithology. The study was conducted by collecting 54 groundwater samples spatially covering the major litho-units. Collected samples were analyzed for electrical conductivity, pH, total dissolved solids (TDS), temperature, Ca, Mg, Na, K, Cl, HCO3, NO3, H4SiO4, PO4, and SO4. The results of the samples analyzed found to vary spatially. Dominance of ion shows that the alkalies are predominant and HCO3 is the dominant anion. Piper facies show that the samples are alkali-carbonate type indicating the predominance of weathering. Most of the parameters exceed the drinking water permissible limit. Standard plots and statistical analysis also indicate weathering as the major process governing the hydrogeochemistry of the groundwater in the region. Relative mobility of cations indicates that the rate of liberation of alkalies from the lithology is more prominent.
Keywords Groundwater . Ion exchange . Weathering . Mobility . Hydrogeochemistry
* M. V. Prasanna [email protected] 1
Department of Earth Sciences, Annamalai University, Annamalai Nagar - 608002, India
2
Department of Applied Geology, Faculty of Engineering and Science, Curtin University, Sarawak Malaysia, CDT 250, 98009 Miri, Sarawak, Malaysia
Introduction Geochemistry of groundwater plays an important role as it explains the groundwater composition and quality which helps in classifying water for different purposes like drinking, domestic, and agriculture as well as in understanding the nature and source of groundwater contamination. This might be attributed to chemical weathering of rock forming minerals which is the major driving force in controlling groundwater chemistry (Chowdhury and Gupta 2011). Weathering of primary and secondary minerals has resulted in the release of cations and silica. In the process of weathering, chemical composition of groundwater is mainly governed by carbonate weathering, silicate weathering, and ion exchange process. Various hydrogeochemical processes and reactions along the groundwater flow direction control the quality (Rosen and Jones 1998; Reddy and Kumar 2010; Tirumalesh et al. 2010; Raju et al. 2011). Hydrogeochemical processes help to delineate the origin and flow direction of groundwater and also helps in understanding the aquifer systems of the study area. Identification of the hydrogeochemical processes in groundwater using classic integrated geochemical methods and geostatistica
Data Loading...
