Health hazardous: nitrate-n in groundwater and soil in Intensified agricultural areas

The study was focused on estimation of nitrate-N in groundwater and soil in intensive agricultural areas mainly on Valikamam East, Jaffna, Sri Lanka. Groundwater samples from sixty eight wells were collected from the intensive agricultural areas and an analysis was done periodically from July 2007 to February 2008 throughout dry and wet season for nitrate-N concentration. Out of sampled area, some of the areas were selected for soil sampling to see the nitrate level in the soil. Nitrate-N in the groundwater and soil was determined by brucine method. The nitrate- N vary in all the months in sixty eight wells and values were ranged from 0.1mg/l to 17.83 mg/l. Out of sixty eight tested wells, 80% of the wells were not recommended for drinking water in intensified agricultural areas and all the wells were accepted for irrigation requirement. High concentration of nitrate-N was observed till 0- 40 cm of soil profile and the concentration was low below the top layer. There was a good correlation between soil nitrate-N to groundwater nitrate-N

A hydrochemical approach to estimate mountain front recharge in an aquifer system in Tamilnadu, India

© 2017 Science Press, Institute of Geochemistry, CAS and Springer-Verlag GmbH Germany Mountain-front recharge (MFR) is a process of recharging an aquifer by infiltration of surface flow from streams and adjacent basins in a mountain block and along a mountain front (MF). This is the first attempt in India to estimate MFR along the foothills of Courtallam using hydrogeochemistry and geostatistical tools. The estimation of MFR has been carried out by collecting groundwater samples along the foothills of Courtallam. Collected water samples were analyzed for major cations and anions using standard procedures. Hydrogeochemical facies show the existence of four water types in this region. Calcium-rich water derived from gneissic rock terrain indicates significant recharge from higher elevation. Log pCO 2 and ionic strength of the samples were also calculated to identify the geochemical process. Majority of the collected samples have sodium-rich water and weak ionic strength, which indicate foothill recharge and low residence time. Silicate and carbonate weathering have an equal interplay along the foothills with a relatively large fraction of Mg from the MF. The spatial diagrams of three factors show that the southern part of the study area is dominated by both weathering and anthropogenic processes, whereas the northern part is dominated by both leaching and weathering processes. Thus, the dominant weathering process represented by the second factor indicates the large recharge process along the foothills