pH as a Key Indicator of Water Quality: A Case Study on Natural and Industrial Water Sources in Malwa Region of Punjab, India

Abstract

pH is a critical factor that affects physicochemical processes in aquatic systems, especially in areas influenced by intensive agriculture and industrial activities. This study aimed to examine how pH influences key physicochemical characteristics of surface and groundwater in the Malwa region of Punjab, India. Water samples were taken from natural surface water bodies and groundwater sources using a stratified sampling design. We used standard analytical procedures from APHA and BIS to measure pH, electrical conductivity (EC), total dissolved solids (TDS), hardness, alkalinity, dissolved oxygen (DO), biochemical oxygen demand (BOD₅), and chemical oxygen demand (COD). The results show that pH values ranged from 6.2 to 8.9, with several sampling locations exceeding BIS permissible limits. TDS concentrations varied from 310 to 2,480 mg/L, hardness values ranged from 180 to 1,120 mg/L, and COD levels reached up to 410 mg/L in areas affected by industrial and agricultural activities. Groundwater showed higher mineralization and organic load compared to surface water, which reflects increased geochemical interactions under confined conditions. Significant correlations between pH and factors like alkalinity, hardness, and TDS underline the role of pH in controlling water chemistry and the movement of contaminants. This study identifies pH as a reliable indicator of physicochemical degradation in surface and groundwater systems and provides region-specific baseline data crucial for assessing water quality and monitoring the environment in the Malwa region.