Assessment of corrosion and scaling potential of the groundwater in the Thanjavur district using hydrogeochemical analysis and spatial modeling techniques

In this study, corrosiveness and scaling potential of groundwater in the Thanjavur district are evaluated based on the chemical analyses of 34 groundwater samples and GIS-based geostatistical mapping techniques. Total dissolved solid values show that six out of 34 samples exceeded the WHO drinking water standard 1000 mg/L. Piper plot shows that majority of the samples are mixed Ca-Mg-CI type, Ca-HCO3 type and Na-Cl. The results of the physicochemical parameters were used to calculate the most popular corrosion and scaling indices such as Langelier index (LI), aggressive index (Al), Ryznar index (RI), Puckorius index (PI) and Larson-Skold index (LS). Results of LI show that 41% samples have corroding tendency (LI <0) and 59% of the samples have scaling tendency (LI > 0). Al has the same result as 41% of the water is moderately corrosive and the remaining has scaling tendency. RI suggests that 88% of the samples have corrosive tendency and 12% have rigorous corrosive tendency. Values of the PI suggest that all the samples were corrosive. Finally, the LS values show that 62% of the samples have scaling tendency and the remaining have corrosion tendency. In general, groundwater in the Thanjavur district shows both corrosive and scaling tendencies, which can cause severe damage to the machineries in the industries. Spatial variation of the corrosive and scaling indices suggests that the central region of the district has more corrosive tendencies and the western and eastern regions have more scaling tendencies.